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Biomedical subjects

X Rogiers

Publications and source records attributed to X Rogiers.

At least 19 recordsLinked to original sources
PubMed2003

[MRCP in primary sclerosing cholangitis].

PURPOSE: Evaluation of MR-cholangiopancreaticography (MRCP) for the diagnosis of primary sclerosing cholangitis (PSC) in correlation with endoscopic retrograde cholangiopancreaticography (ERCP) and in comparison to the diagnostic accuracy of various T2-weighted sequences. METHODS AND MATERIALS: Fifty-five patients (34 males, 21 females; mean age 40 years, range 16 to 65 years) with suspected PSC were examined in a 1.5 T MR unit (Magnetom Vision, Siemens, Erlangen), using breath-hold transverse and coronal HASTE, paracoronal RARE and thin-sliced HASTE (TS-HASTE) sequences. Applying a five-point-scale, two blinded investigators assessed the image quality for ROC analysis. Morphologic criteria of PSC were documented and correlated with ERCP, which served as the gold standard, and sensitivity, specificity and diagnostic accuracy were calculated. RESULTS: PSC was confirmed in 40 of 55 patients (ERCP 55 of 55, liver biopsy 37 of 55), with concomitant chronic ulcerative colitis in 27 and Crohn's disease in 6 of the 40 patients. Qualitative analysis of the image quality showed no significant difference between RARE, HASTE and thin-sliced HASTE sequences (3.4/3.5/3.2). The RARE sequence had the highest sensitivity (97 %), specificity (64 %) and accuracy (84 %) for the detection of PSC. The difference between HASTE and thin-sliced HASTE was statistically significant (p < 0.01). Of the 40 patients with confirmed PSC, 29 were followed by MRI and 3 underwent a liver transplantation within the follow-up period. A Klatskin tumor, which was misdiagnosed by MRCP, was diagnosed by brush biopsy in 1 of the 40 patients. Interobserver variability was adequate to good (kappa 0.4 to 0.7), depending on the chosen sequence. CONCLUSION: MRCP seems to be a reliable non-invasive imaging method to diagnose and follow PSC. The RARE sequence showed the highest diagnostic accuracy of the T2-weighted sequences.

Adolescent↗
PubMed2002

The oxidative metabolism of polymorphonuclear neutrophils in pediatric liver graft recipients.

BACKGROUND: Data on the oxidative metabolism of polymorphonuclear neutrophils (PMN) after solid organ transplantation are very limited. We hypothesized that immunosuppressive agents reduce the capacity of PMN to produce reactive oxygen species, such as O2(-), H2O2, OH, and OCL(-) leading to an increased susceptibility to infectious complications after liver transplantation. METHODS: A lucigenin-enhanced chemiluminescence (CL) assay was used with soluble and particulate stimuli to study the oxidative metabolism of PMN in pediatric liver graft recipients. Sixteen patients (median age: 2.4 yr) were enrolled in a prospective study and integrated CL response was compared with the CL activity of 29 healthy controls. RESULTS: In the second week post-transplant, we found a significantly reduced CL activity. Pre-operatively, and after lowering steroids and cyclosporin A (CsA) the oxidative burst was normal. CONCLUSIONS: Our data suggest that CsA and steroids may not only influence T and B cells but also PMN, which may be a relevant factor for the incidence of infectious complications in pediatric liver graft recipients.

Adolescent↗
PubMed2002

[Formation of portal venous collaterals after ligation of the portal vein for induction of liver regeneration].

PURPOSE: Unilateral occlusion of the portal vein induces contralateral lobar hypertrophy - in contrast to complete portal vein occlusion which will result in a cavernous transformation. The impact of the formation of collaterals in partial portal vein occlusion is not sufficiently known. The lobar-hypertrophy- phenomenon is in clinical use for several years to induce iatrogenic liver growth to enable extended resections. After portal vein ligation in patients prior to extended hepatic resections, we noticed a perfusion of the formerly occluded side on CT. Using the well-established mini pig model, we were interested whether portal collaterals are formed as cause of the reperfusion. Ex-situ angiograms of the liver were used for the depiction of collaterals. MATERIALS AND METHODS: Using a median laparotomy as access for preparation of the hepatoduodenal ligament, a proximal left portal vein ligation was performed in eight mini pigs under general anesthesia. The total arrest of the portal blood flow (except in segments VI and VII) was documented by duplex ultrasound. After 4 weeks, all pigs were sacrificed and the weight of the ligated liver segments and non-ligated liver segments was measured and compared to a sham group (n = 5). After insertion of a guiding sheath, an ex-situ DSA of the portal vein was acquired. RESULTS: Compared with the sham group, the liver weight increased by 60 % (23 - 99 %, std. dev. 30 %) in segments VI and VII. Atrophy of the ligated segments was signified by a weight loss of 10 % (standard deviation 15 %). The ex-situ angiograms revealed a uniform pattern of collaterals with subsequent complete total recanalization of the formerly occluded portal vein distal from the ligation. The collaterals reduced the portal venous flow rate. CONCLUSION: After portal vein ligation, uniform collateralization results in recanalization of the occluded portal vein. The extent of the collaterals exceeds the known cavernous transformation. The increase in liver volume is not restrained by the formation of collaterals.

Aged↗
PubMed2001

Th2 cytokine profile in infants predisposes to improved graft acceptance after liver transplantation.

BACKGROUND: The T helper cell type 1 (Th1) cytokines interleukin (IL)-2 and interferon (IFN)-gamma are mediators of acute graft rejection after liver transplantation and Th2 cytokines, such as IL-4 and IL-10, may have a protective role and correlate with graft acceptance. To test the hypothesis that infants aged <1 year have an immunological advantage with regard to graft acceptance because of a partially immature immune system with a physiological balance toward a Th2 cytokine profile, we conducted the present study. METHODS: We compared the T helper serum cytokine profiles in 105 infants and children after liver transplantation with or without acute graft rejection and analyzed the normal age-distributed concentrations of T helper cytokines in 51 healthy controls. RESULTS: The incidence of acute graft rejection was as follows: 0 to 12 months, 26.8%; 1 to 3 years, 40.0%; and >3 years, 71.8%. There was a significantly lower incidence of acute rejection in infants 0 to 12 months of age compared with children >1 year (11/41 vs. 38/64; P=0.001). In healthy infants, significant increasing Th1 cytokine concentrations and decreasing Th2 cytokine concentrations were found with increasing age. Patients with acute rejection had significantly higher values of Th1 cytokines compared with nonrejecting subjects, who had significantly higher concentrations of Th2 cytokines. A longitudinal analysis of serum cytokines from patients showed that changes of the cytokine patterns in the follow-up did not differ significantly from preoperative values, except in the 4 weeks posttransplant. CONCLUSIONS: We conclude from the data that the physiological balance toward a Th2 cytokine profile of infants in the first months of life predisposes to improved graft acceptance. Transplantation of children with biliary atresia as early as possible, avoiding Th1 stimulation by recurrent infections and vaccinations, may have a positive impact on overall tolerance.

Acute Disease↗
PubMed2001

Hepatocyte transplantation using biodegradable matrices in ascorbic acid-deficient rats: comparison with heterotopically transplanted liver grafts.

BACKGROUND: Hepatocyte transplantation using polymeric matrices is under investigation as an alternative therapy for metabolic liver diseases. Long-term engraftment of hepatocytes in polymers has been demonstrated. However, the metabolic activity of hepatocytes in such devices has never been assessed in direct comparison with liver grafts. METHODS: Hepatocyte and partial liver transplantation were evaluated in the scurvy-prone osteogenic disorder Shionogi rat model. Biodegradable poly glycolic acid matrices seeded with hepatocytes equivalent to 20% of the recipient's liver mass, or 20% liver grafts were heterotopically transplanted into ascorbic acid- (AsA) deficient recipients. Recipients of cell-free matrices or AsA-deficient liver grafts served as controls. Recipients were set on AsA-free diet after transplantation. Plasma AsA levels, AsA concentrations in liver and adrenal gland tissue, and body weight ratios were assessed and H&E histology was performed. RESULTS: Recipients from the control groups showed symptoms of scurvy at 1 month after cessation of AsA supply. Hepatocyte transplantation and auxiliary liver transplantation prevented symptoms of scurvy and increased plasma and tissue AsA levels and body weight ratios. AsA levels in recipients of 20% liver grafts were comparable to normal control animals. CONCLUSIONS: Hepatocytes transplanted in polymeric matrices are able to compensate for liver-based metabolic deficiencies. Hepatocyte transplantation improves plasma AsA levels in AsA-deficient recipients. However, auxiliary liver grafts are superior to hepatocyte grafts in improving metabolic parameters. Further research work is needed to increase the efficiency of liver cell transplantation with regard to a clinical application.

Animals↗
PubMed2001

First experience with basiliximab in pediatric liver graft recipients.

Several studies have shown a significant reduction of acute cellular graft rejection in adult liver and kidney graft recipients treated with monoclonal anti-interleukin-2 (IL-2)-receptor antibodies. The mechanism was inhibition of activated T-helper cells by blocking the alpha-chain (CD25) of the IL-2 receptor. The pilot study described here evaluated the use of basiliximab in pediatric liver transplantation (LTx), which is the first report on its use in children. Fifty-two liver-transplanted children were analyzed in this study. A matched-pair historical control group (n = 26) received cyclosporin A (CsA) and prednisolone, and patients in the basiliximab group (n = 26) were treated with low-dose CsA and basiliximab (after reperfusion and on day 4 post-transplant). The incidences were compared of acute graft rejections, infectious complications, and the adverse effects of immunosuppressive medication within the first 6 months post-transplant. The incidence of acute rejection was significantly higher in the control group (61.5% vs. 11.5%, p = 0.0004). The frequency of infectious complications was similar (46.1% vs. 53.8%). Patients in the basiliximab group showed less arterial hypertension; however, the differences were not statistically significant (30.7% vs. 7.7%, p = 0.07). Nephrotoxicity, hepatotoxicity or neurotoxicity were only seen in the control group (7.7%; 3.8%; 3.8%, respectively). Hence, the use of basiliximab in combination with CsA and steroids in pediatric liver transplant recipients is safe and reduces the incidence of acute graft rejection. Further studies are needed to confirm our preliminary results and to analyze long-term effects on post-transplant lymphoproliferative disease, chronic rejection, and patient survival.

Antibodies, Monoclonal↗
PubMed2001

Repopulation of mouse liver with human hepatocytes and in vivo infection with hepatitis B virus.

Mice containing livers repopulated with human hepatocytes would provide excellent in vivo models for studies on human liver diseases and hepatotropic viruses, for which no permissive cell lines exist. Here, we report partial repopulation of the liver of immunodeficient urokinase-type plasminogen activator (uPA)/recombinant activation gene-2 (RAG-2) mice with normal human hepatocytes isolated from the adult liver. In the transplanted mice, the production of human albumin was demonstrated, indicating that human hepatocytes remained functional in the mouse liver for at least 2 months after transplantation. Inoculation of transplanted mice with human hepatitis B virus (HBV) led to the establishment of productive HBV infection. According to human-specific genomic DNA analysis and immunostaining of cryostat liver sections, human hepatocytes were estimated to constitute up to 15% of the uPA/RAG-2 mouse liver. This is proof that normal human hepatocytes can integrate into the mouse hepatic parenchyma, undergo multiple cell divisions, and remain permissive for a human hepatotropic virus in a xenogenic liver. This system will provide new opportunities for studies on etiology and therapy of viral and nonviral human liver diseases, as well as on hepatocyte biology and hepatocellular transplantation.

Adult↗
PubMed2001

Hepatic involvement in hereditary hemorrhagic telangiectasia: an unusual indication for liver transplantation.

Hereditary hemorrhagic telangiectasia (HHT) is a vascular disease with multiple organ manifestations. Severe hepatic involvement is an unusal indication for liver transplantation. We report on a 39-year-old woman diagnosed with HHT and decompensation of the disease during her second pregnancy. After delivery, hemobilia occurred, followed by severe therapy-resistant cholangitis and progressive liver dysfunction. Because of progressive loss of liver function, orthotopic liver transplantation needed to be performed. The various aspects of liver involvement in Osler's disease, diagnosis, and therapy are discussed.

Adult↗
PubMed2001

[Native magnetic resonance tomography imaging of the Morris hepatoma (MH-7777A) in the rat].

UNLABELLED: Goal of the study presented was to establish an oncological animal model for implantable and differentiated hepatoma in the rat and to evaluate imaging of the tumor induced using MRI. MATERIAL AND METHODS: 20 male buffalo rats underwent tumor cell implantation of 150,000 MH7777-A cells via laparotomy. After 12 days MRI was performed T1w SE, T2w TSE fs, TIRM) for tumor detection and measurement of size. Immediately there after all rats were killed and macroscopic and histological examination performed. Pathological findings were correlated with MRI. RESULTS: In 5 out of 20 animals no tumor was found. Mean size of the hepatomas in 15 animals was 3.1 mm (+/- 1.7 mm). On MRI 14 out of 15 tumors were detectable. Mean diameter in MRI was 2.7 mm (+/- 1.5 mm; 1-5 mm). T2w TSE was superior for tumor detection compared with the TIRM, while the best anatomic depiction was offered by T1w SE. CONCLUSIONS: The MH7777-A tumor model presents with a rate of 75% even with the small tumor cell amount of 150,000 cells. With MRI using T2 weighted sequences with fat saturation a detection of tumors with diameters of 1 mm is reliably possible in 93% of the cases.

Animals↗
PubMed2001

[Living organ donation vs. cadaveric donation - study of liver transplanted children and their families].

There is only scarce information on the quality of life of child recipients of liver transplants and their families. Particularly children with a living related graft and their families never have been compared to children who received a cadaveric graft and their families. We investigated the following issues in our study: How do parents and children from participating families rate their strain, their quality of life and their relationships within their family? Do families with a living - related donor differ from those with a cadaveric donor? What do living donors and their partners think about the donation retrospectively? The study was conducted with 106 participants from 50 families (42 mothers, 40 fathers, and 24 children older than 6 years). In 20 of these families, a living transplantation had been performed. Participants were interviewed and asked to fill out several questionnaires. School-aged children with a liver transplant show good social integration among their peers and in school. The child's disease, however, has a great impact on the family. Family members show a reduction in social contact, and an increase in marital crises, and problematic relations amongst siblings. Families in which a cadaveric graft was performed, are less satisfied with life, and show more symptoms of exhaustion. Every family studied possessed or acquired - a high degree of internal or external coping resources. Living - related donors tried hard to obtain an understanding of the medical context. The partner, rather than the donor himself, feels anxious before the donation. The limited time available for the decision to donate is not perceived by the donors to be critical. Ten percent of living donors feel "a little" that their health is affected. The decision to donate is supported "strongly" or "very strongly" by the partners in 80 % of the cases. A possible strain on the child through the expectation of gratitude by the donor is stated by 20 %. All of the donors agree that if they were to be asked today, they would donate again, only one of the partners raised objections. In summary, as a retrospective pilot study, this study primarily generates hypotheses rather than testing them and helps to develop research tools for the field. Results suggest that a psychological support be made available both prior to and following the operation, not only for the children but also for their families, with particular attention to the partners of the living donors and the siblings of the affected children.

Adolescent↗
PubMed2001

Is there still a need for living-related liver transplantation in children?

OBJECTIVE: To assess and compare the value of split-liver transplantation (SLT) and living-related liver transplantation (LRT). SUMMARY BACKGROUND DATA: The concept of SLT results from the development of reduced-size transplantation. A further development of SLT, the in situ split technique, is derived from LRT, which itself marks the optimized outcome in terms of postoperative graft function and survival. The combination of SLT and LRT has abolished deaths on the waiting list, thus raising the question whether living donor liver transplantation is still necessary. METHODS: Outcomes and postoperative liver function of 43 primary LRT patients were compared with those of 49 primary SLT patients (14 ex situ, 35 in situ) with known graft weight performed between April 1996 and December 2000. Survival rates were analyzed using the Kaplan-Meier method. RESULTS: After a median follow-up of 35 months, actual patient survival rates were 82% in the SLT group and 88% in the LRT group. Actual graft survival rates were 76% and 81%, respectively. The incidence of primary nonfunction was 12% in the SLT group and 2.3% in the LRT group. Liver function parameters (prothrombin time, factor V, bilirubin clearance) and surgical complication rates did not differ significantly. In the SLT group, mean cold ischemic time was longer than in the LRT group. Serum values of alanine aminotransferase during the first postoperative week were significantly higher in the SLT group. In the LRT group, there were more grafts with signs of fatty degeneration than in the SLT group. CONCLUSIONS: The short- and long-term outcomes after LRT and SLT did not differ significantly. To avoid the risk for the donor in LRT, SLT represents the first-line therapy in pediatric liver transplantation in countries where cadaveric organs are available. LRT provides a solution for urgent cases in which a cadaveric graft cannot be found in time or if the choice of the optimal time point for transplantation is vital.

Adolescent↗
PubMed2001

FDG PET in the diagnosis of hilar cholangiocarcinoma.

Resectional surgery offers a curative intent and a survival benefit for patients with hilar cholangiocarcinoma, but is associated with high morbidity. Since morphological imaging cannot solve differential diagnosis preoperatively, in order to exclude patients inappropriate to this aggressive surgery, we evaluated the impact of functional imaging using fluorodeoxyglucose positron emission tomography (FDG PET) in the detection of cholangiocarcinoma and its usefulness in the differentiation from benign Klatskin tumour-mimicking lesions. Fifteen consecutive patients aged 47-78 years underwent standardized whole-body FDG PET with attenuation correction before potentially curative surgery using a conventional full-ring PET scanner with an axial field-of-view of 16.2 cm. FDG PET was evaluated visually and semiquantitatively using tumour-to-background ratios (T/B) ratios. All lesions were evaluated histopathologically. FDG PET presumed to be indicative for carcinoma was positive in 12 of 15 patients, true positive in 10 (T/B ratio, 3.2+/-1.9) and false positive in two of them (T/B ratios, 2.1 and 2.8) with Klatskin tumour-mimicking lesions. While all true positive PET results were seen in the tubular type of cholangiocarcinoma with a high amount of tumour cells and only low production of mucus, a false negative FDG PET in three patients was observed in mucinous adenocarcinoma. Additionally, FDG PET detected locoregional lymph nodes in two patients and distant metastases in a further three patients. Due to false positive results FDG PET does not allow the differentiation of benign from malignant lesions, and FDG PET should be avoided in patients with mucinous cholangiocarcinoma. However, FDG PET may have significant influence on the treatment strategy in as much as 20% of the patients, since it may detect distant metastases.

Aged↗