TIPS geometry influences patency.

OBJECTIVE: The purpose of this study was to evaluate potential causes of Transjugular intrahepatic portosystemic shunt (TIPS) dysfunction. MATERIAL AND METHODS: We retrospectively evaluated 26 patients who required TIPS revision (group I) and 24 patients who did not require any further intervention (group II) within the first two years following TIPS implantation. The distance of the distal end of the stent to the hepatocaval junction was measured. Furthermore, the angle between the stent and the portal vein (inflow) and the angle between the stent and the hepatic vein (outflow) were measured. Furthermore, the following data were evaluated: pre- and postinterventional portal pressure gradients, maximal postinterventional flow and blood values [C-reactive protein (CRP), bilirubin, glutamic-oxaloacetic transaminase (GOT), glutamic-pyruvic transaminase (GPT)]. RESULTS: Compared with control subjects, patients who required TIPS revision showed a significantly longer distance from the distal end of the stent to the hepatocaval junction (I: 17.3 ±â€Š10 mm, II: 6.7 ±â€Š5.7 mm, p < 0.001). There was a statistically significant correlation between the above named distance and the time to revision (Pearson's correlation coefficient, r = 0.5, p = 0.01). In addition, patients with TIPS revision had a significantly larger angle of portalvenous inflow (alpha angle) than the control group (I: 100.5 ±â€Š31.5°, II: 64.5 ±â€Š31.6°, p < 0.001). CONCLUSION: Our results show that the distance from the end of the stent to the hepatocaval junction and the angle of portalvenous inflow are technical factors that may influence the shunt's patency rate. Of these two, the distance to the hepatocaval junction can be influenced easily by the interventionalist.

[Hepatic cholestasis resulting from a long-standing enterothorax: a case report]. / Langjähriger Enterothorax als ungewöhnliche Ursache einer Cholestase: ein Fallbericht.

BACKGROUND: Due to the lack of symptoms an enterothorax frequently remains undetected in adults. Most symptomatic patients complain about bowel obstruction and a surgical repair of the diaphragmatic defect, particularly with a mesh, is mandatory. METHODS: This report presents the case of a 72-year-old female patient with a history of an upside-down stomach presenting with a painless jaundice and signs of liver cirrhosis. CLINICAL COURSE: The preoperative work-up revealed an enterothorax with compression of the main bile duct. Explorative laparotomy showed a liver cirrhosis with distinct intrahepatic cholestasis, a hydropic gallbladder and confirmed a right-sided diaphragmatic defect with an enterothorax. After reposition of the intestine, a cholecystectomy, bile duct revision and the closure of the diaphragmatic defect using a mesh were performed. CONCLUSION: Diaphragmatic defects are the basis for the formation of an enterothorax which may be associated with a complicated clinical course. Therefore, in cases of coincidental diagnosis, even in asymptomatic patients, surgical repair should be performed in order to prevent serious complications as presented in this case.

Perioperative outcome and long-term survival for intrahepatic cholangiocarcinoma after portal vein embolization and subsequent resection: A propensity-matched study.

INTRODUCTION: In view of the high therapeutic value of surgical resection for intrahepatic cholangiocarcinomas (ICC), our study addresses the question of clinical management and outcome in case of borderline resectability requiring hypertrophy induction of the future liver remnant prior to resection. METHODS: Clinical data was collected of all primary ICC cases receiving major liver resection with or without prior portal vein embolization (PVE) from a single high-volume center. PVE was performed via a percutaneous transhepatic access. Propensity score matching was performed. Perioperative morbidity was assessed as well as long-term survival with a minimum follow-up of 36 months. RESULTS: No significant difference in perioperative morbidity was seen between the PVE and the control group. For the PVE group, median OS was 28 months vs. 37 months for the control group (p = 0.418), median DFS 18 and 14 months (p = 0.703). Disease progression during hypertrophy was observed in 38% of cases. Here, OS and DFS was reduced to 18 months (p = 0.479) and 6 months (p = 0.013), respectively. In case of positive N-status or multifocal tumor (MF+) OS was also reduced (18 vs. 26 months, p = 0.033; MF+: 9 vs. 36months p = 0.013). CONCLUSION: Our results suggest that the surgical therapy in case of borderline resectability offers acceptable results with non-inferior OS rates compared to cases without preoperative hypertrophy induction and comparable oncological features. In the presence of additional risk factors (multifocal tumor, lymph node metastasis, PD during hypertrophy) the OS is notably reduced.

Cholestatic liver diseases from child to adult: the diversity of MDR3 disease.

The phospholipidfloppase MDR3 (gene symbol: ABCB4) is expressed in the canalicular membrane of hepatocytes and mediates the biliary excretion of phosphatidylcholine, which is required for the formation of mixed micelles in bile. Several mutations of ABCB4 have been identified, which cause cholestatic liver diseases of varying severity including progressive familial intrahepatic cholestasis type 3 (PFIC-3), intrahepatic cholestasis of pregnancy (ICP) and the low phospholipid associated cholelithiasis syndrome (LPAC). Here, we report on four new (S1076N; L 23Hfs16X; c.286 + 1G > A; Q 1181E) and one known (S27G) MDR3 mutations in eight patients of three families. The patients presented with a wide spectrum of liver diseases. The clinical presentation and decisive laboratory findings or the association to a trend-setting family history led to the identification of the genetic background in these patients. Even the same mutation may be associated with varying disease progression.

Biological significance of unwinding capability of nuclear matrix-associating DNAs.

Matrix attachment regions (MARs) are thought to separate chromatin into topologically constrained loop domains. A MAR located 5' of the human beta-interferon gene becomes stably base-unpaired under superhelical strain, as do the MARs flanking the immunoglobulin heavy chain gene enhancer; in both cases a nucleation site exists for DNA unwinding. Concatemerized oligonucleotides containing the unwinding nucleation site exhibited a strong affinity for the nuclear scaffold and augmented SV40 promoter activity in stable transformants. Mutated concatemerized oligonucleotides resisted unwinding, showed weak affinity for the nuclear scaffold, and did not enhance promoter activity. These results suggest that the DNA feature capable of relieving superhelical strain is important for MAR functions.

Probiotic yogurt in the elderly with intestinal bacterial overgrowth: endotoxaemia and innate immune functions.

A study was conducted in healthy elderly living independently in senior housing to assess the impact of a probiotic yoghurt supplement on small intestinal bacterial overgrowth. Twenty-three participants with positive and thirteen participants with negative hydrogen breath test were studied before and after a period of 4 weeks of probiotic yoghurt administration. Intestinal permeability, plasma endotoxin levels, phagocytic activity of leucocytes, cytokine production by monocytes and free radical response of neutrophils were determined. Intestinal permeability was similar for the two groups and was unaffected by probiotic treatment. Both plasma endotoxin levels and the basal phagocytic activity of leucocytes decreased after yoghurt intake in the two groups. Exposure of monocytes and neutrophils ex vivo led to an increased cytokine response and free radical response, respectively. The normalisation of the various cytokine responses was more apparent in the group with positive breath test. In addition, the plasma levels of lipoplysaccharide binding protein and soluble CD14, lipoplysaccharide pattern recognition receptors and surrogate markers of lipoplysaccharide permeability were diminished by the end of the study. In conclusion, probiotic administration in the elderly normalises the response to endotoxin, and modulates activation markers in blood phagocytes, and therefore may help reduce low-grade chronic inflammation.

Effect of physical cues of altered extract media from biodegradable magnesium implants on human gingival fibroblasts.

Volume stable barrier membranes made of magnesium are very promising in Guided Bone Regeneration (GBR) to treat periodontal bone defects in dentistry due to their excellent biocompatibility and biodegradability. During the degradation process the cells are exposed to the alteration of various parameters, so called physical cues, involving surface alterations due to the formed corrosion layer and medium alterations arising from the dissolved corrosion products. Cell migration of human gingival fibroblasts (HGF), as a crucial parameter for optimal healing process in GBR, has been investigated on magnesium membranes and revealed that medium alterations by dissolved corrosion products have a higher impact on cell migration than surface alterations. However, the effect of each altered medium parameter on cell migration has not been adequately studied, but their roles are crucial to explain the slower migration rate on magnesium surfaces compared to titanium and tissue culture plastic surfaces. Our study investigates the single effect of Mg2+, Ca2+, H2 and increased osmolality as well as the effect of magnesium extracts, which contain a dynamic mixture of previous parameters on cell migration, proliferation and viability of HGF. We showed that at 75 mM Mg2+ concentration and at 0 mM Ca2+, respectively, the cell migration rate is greatly reduced. In complex magnesium extract media, we found that a temporarily increased ratio of Mg2+ to Ca2+ conditioned a slow HGF migration rate. Based on these findings and the characterization of supernatants from HGF migration assays on Mg membranes, we propose, that the slower migration rate of HGF can be explained by the altered ratio of Mg2+ to Ca2+, caused by increasing concentrations of Mg2+ and decreasing concentrations of Ca2+ in the vicinity of the corroding Mg implant, combined with a constantly increased molecular hydrogen concentration in the supernatant. These results are cell type specific and should be checked carefully, if necessary, for Mg implant performance. STATEMENT OF SIGNIFICANCE: The study is providing a systematic approach to explain the main effects of extract medium parameters (physical cues) such as magnesium or calcium ion concentration, osmolality and dissolved molecular hydrogen and CO2 in cell culture media modified by co-incubating with corroding magnesium implants on the migration rate of human gingival fibroblasts (HGF). This study uncovers for the first time the combinatory effect of slightly increased molecular hydrogen and the change in Mg2+/Ca2+ ratio on HGF cell migration.

Alcohol, intestinal bacterial growth, intestinal permeability to endotoxin, and medical consequences: summary of a symposium.

This report is a summary of the symposium on Alcohol, Intestinal Bacterial Growth, Intestinal Permeability to Endotoxin, and Medical Consequences, organized by National Institute on Alcohol Abuse and Alcoholism, Office of Dietary Supplements, and National Institute of Diabetes and Digestive and Kidney Diseases of National Institutes of Health in Rockville, Maryland, October 11, 2006. Alcohol exposure can promote the growth of Gram-negative bacteria in the intestine, which may result in accumulation of endotoxin. In addition, alcohol metabolism by Gram-negative bacteria and intestinal epithelial cells can result in accumulation of acetaldehyde, which in turn can increase intestinal permeability to endotoxin by increasing tyrosine phosphorylation of tight junction and adherens junction proteins. Alcohol-induced generation of nitric oxide may also contribute to increased permeability to endotoxin by reacting with tubulin, which may cause damage to microtubule cytoskeleton and subsequent disruption of intestinal barrier function. Increased intestinal permeability can lead to increased transfer of endotoxin from the intestine to the liver and general circulation where endotoxin may trigger inflammatory changes in the liver and other organs. Alcohol may also increase intestinal permeability to peptidoglycan, which can initiate inflammatory response in liver and other organs. In addition, acute alcohol exposure may potentiate the effect of burn injury on intestinal bacterial growth and permeability. Decreasing the number of Gram-negative bacteria in the intestine can result in decreased production of endotoxin as well as acetaldehyde which is expected to decrease intestinal permeability to endotoxin. In addition, intestinal permeability may be preserved by administering epidermal growth factor, l-glutamine, oats supplementation, or zinc, thereby preventing the transfer of endotoxin to the general circulation. Thus reducing the number of intestinal Gram-negative bacteria and preserving intestinal permeability to endotoxin may attenuate alcoholic liver and other organ injuries.

Scaffold/matrix attachment regions (S/MARs): relevance for disease and therapy.

There is increasing awareness that processes, such as development, aging and cancer, are governed, to a considerable extent, by epigenetic processes, such as DNA and histone modifications. The sites of these modifications in turn reflect their position and role in the nuclear architecture. Since epigenetic changes are easier to reverse than mutations, drugs that remove or add the chemical tags are at the forefront of research for the treatment of cancerous and inflammatory diseases. This review will use selected examples to develop a unified view that might assist the systematic development of novel therapeutic regimens.

The hepatitis C virus and immune evasion: non-structural 3/4A transgenic mice are resistant to lethal tumour necrosis factor alpha mediated liver disease.

BACKGROUND: The hepatitis C virus (HCV) establishes chronic infection by incompletely understood mechanisms. The non-structural (NS) 3/4A protease/helicase has been proposed as a key complex in modulating the infected hepatocyte, although nothing is known about the effects this complex exerts in vivo. AIM: To generate mice with stable and transient hepatocyte expression of the HCV NS3/4A proteins to study its effects in vivo. METHODS: NS3/4A expression was determined by western blot and immunohistochemistry. Two independent pathologists determined the liver histology. Hepatic immunity was characterised by quantifying intrahepatic immune cell subsets. Liver damage was induced using carbon tetrachloride (CCl(4)), lipopolysaccaride (LPS), tumour necrosis factor alpha (TNFalpha), and anti-Fas antibody. RESULTS: Expression of NS3/4A was restricted to the cytoplasm of hepatocytes, and did not cause liver cancer or any spontaneous liver pathology. However, the presence of NS3/4A modulated the intrahepatic immunity, as follows: first, the CD4+ T cell and type I/II dendritic cell subsets were reduced in transgenic livers; second, NS3/4A protected hepatocytes from liver damage mediated in vivo by CCl(4), LPS, TNFalpha, but not FAS; and third, both stable and transiently NS3/4A transgenic mice were resistant to lethal doses of liver targeted TNFalpha, and the resistance could be reverted by treatment with a p38 mitogen activated protein kinase inhibitor (MAPK). CONCLUSIONS: Hepatic expression of NS3/4A does not induce spontaneous liver disease. NS3/4A does, however, alter the intrahepatic immune cell subsets and protects hepatocytes against TNFalpha induced liver damage in vivo. The TNFalpha resistance can be reverted by treatment with a p38 MAPK inhibitor. This represents a new immune evasion strategy conferred by NS3/4A.

Differential effects of vasodilatory prostaglandins on focal adhesions, cytoskeletal architecture, and migration in human aortic smooth muscle cells.

OBJECTIVE: Cyclooxygenases 1 and 2 are expressed in atherosclerotic arteries, and local generation of prostacyclin and prostaglandin E2 (PGE2) occurs. However, the role of cyclooxygenases and individual prostaglandins during plaque progression is currently uncertain. The present study characterizes the effect of vasodilatory prostaglandins on morphology, focal adhesion (FA) function, and migration in human aortic smooth muscle cells (SMCs). METHODS AND RESULTS: The stable prostacyclin analog iloprost transiently induced: (1) disassembly of FA and stress fibers, (2) partial retraction and rounding of SMCs, (3) hypophosphorylation of FA kinase (FAK) and paxillin, and (4) inhibition of platelet-derived growth factor-BB-induced migration. Inhibition of FAK phosphorylation and morphological changes were mimicked by forskolin, inhibited by H89, and prevented by the protein tyrosine phosphatase inhibitor vanadate and by calpeptin. PGE2 was by far less efficient with respect to all parameters investigated. This difference correlated with the respective cAMP induction in response to iloprost and PGE2. CONCLUSIONS: Inhibition of FAK phosphorylation and FA function is a new target of vasodilatory prostaglandins, which might be causally involved in the antimigratory effects of prostaglandins. Importantly, prostacyclin analogs and PGE2 differ dramatically with respect to dephosphorylation of FAK and inhibition of migration, which might be of relevance for their respective functions in atherosclerosis.

Evaluation of sequence motifs found in scaffold/matrix-attached regions (S/MARs).

Based on the contents of the database S/MARt DB, the most comprehensive data collection of scaffold/matrix-attached regions (S/MARs) publicly available thus far, we initiated a systematic evaluation of the stored data. By analyzing the 245 S/MAR sequences presently described in this database, we found that the S/MARs contained in this collection are generally AT-rich, with certain significant exceptions. Comparative analyses showed that most of the AT-rich motifs which were found to be enriched in S/MARs are also enriched in randomized S/MAR sequences of the same AT content. Some sequence patterns previously suggested to be characteristic for S/MARs were also investigated, among them potential binding sites for homeodomain transcription factors. Even though hexanucleotides containing the core motif of homeodomain factors were frequently observed in S/MARs, only a few potential binding sites for these factors were found enriched when compared with regulatory regions or exon sequences. All our analyses indicated that, on average, the observed frequency of motifs in S/MAR elements is largely influenced by the AT content. Our results can serve as a guideline for further improvements in the definition of S/MARs, which are now believed to constitute the functional coordinate system for genomic regulatory regions.

Scaffold/matrix-attached regions: structural properties creating transcriptionally active loci.

The expression characteristics of the human interferon-beta gene, as part of a long stretch of genomic DNA, led to the discovery of the putative domain bordering elements. The chromatin structure of these elements and their surroundings was determined during the process of gene activation and correlated with their postulated functions. It is shown that these "scaffold-attached regions" (S/MAR elements) have some characteristics in common with and others distinct from enhancers with which they cooperate in various ways. Our model of S/MAR function will focus on their properties of mediating topological changes within the respective domain.

Stress-induced duplex DNA destabilization in scaffold/matrix attachment regions.

S/MARs are DNA elements 300 to several thousand base-pairs long, which are operationally defined by their affinity for the nuclear scaffold or matrix. S/MARs occur exclusively in eukaryotic genomes, where they mediate several functions. Because S/MARs do not have a clearcut consensus sequence, the characteristics that define their activity are thought to be structural. Ubiquitous S/MAR binding proteins have been identified, but to date no unique binding sequence or structural motif has been found. Here we show by computational analysis that S/MARs conform to a specific design whose essential attribute is the presence of stress-induced base-unpairing regions (BURs). Stress-induced destabilization (SIDD) profiles are calculated using a previously developed statistical mechanical procedure in which the superhelical deformation is partitioned between strand separation, twisting within denatured regions, and residual superhelicity. The results of these calculations show that BURs exhibit a succession of evenly spaced destabilized sites that would render part or all of the S/MAR sequence single stranded at sufficient superhelicity. These analyses are performed for a range of sequenced S/MAR elements from the borders of eukaryotic gene domains, from centromeres, and from positions where S/MARs are known to support the action of an enhancer. The results reported here are in excellent agreement with earlier in vitro chemical reactivity studies. This approach demonstrates the potential for computational analysis to predict the points of division of the eukaryotic genome into functional units (domains), and also to locate certain cis-regulatory sequences.

Coping with kinetic and thermodynamic barriers: RMCE, an efficient strategy for the targeted integration of transgenes.

Site-specific recombinases have become powerful tools for the targeted integration of transgenes into defined chromosomal loci. They have been successfully used both to achieve predictable gene expression in cell culture and for the systematic creation of transgenic animals. A recent improvement of this method, the recombinase-mediated cassette exchange procedure (RMCE), permits expression in the absence of any co-expressed selection marker gene.

Germ-line transcripts of the immunoglobulin lambda J-C clusters in the mouse: characterization of the initiation sites and regulatory elements.

Transcription of unrearranged immunoglobulin gene segments strongly correlates with their accessibility to the V(D)J recombination machinery. The regulatory mechanisms governing this germ-line transcription are still poorly defined. In order to identify new regulatory elements, we first carried out a detailed characterization of the transcription initiation sites for the J-C germ-line transcripts, using rapid amplification of 5' cDNA ends, assisted by a template switching mechanism at the 5'-end of the RNA. Transcripts were observed that initiated heterogeneously, starting up to 293 (lambda1), 116 bp (lambda2) and 79 bp (lambda3) upstream from the respective Jlambda gene segment. Additional RT-PCR analysis revealed the existence of germ-line transcripts of lambda and also of kappa that initiate even more upstream of these transcription initiation sites, although their frequencies were low. Promoter activity was detected in vitro 5' of Jlambda2, with the minimal promoter activity mapping to the region between positions -35 and -120. In addition, computer analysis allowed the prediction of a nuclear scaffold/matrix attachment (S/MAR) region between the two J-C gene clusters at each hemi-locus. This region between the lambda1/lambda3 clusters binds to the nuclear matrix in vitro, and J-C lambda1 germ-line transcription initiates a short distance downstream from this S/MAR element.

Modeling the LPS-induced effects on transcription factor activation and gene expression in murine macrophages.

Macrophages within the liver are of particular importance for a functional defense against bacterial infection. They exhibit a complex response to lipopolysaccharide and secrete a variety of pro-inflammatory cytokines and chemokines that both coordinate the immune response and regulate activity of the macrophages, themselves. In this context, the dynamic of pathway activation and gene expression is important for a better understanding of the role of activated macrophages in healthy and diseased states. Therefore, we present a representative model of LPS-induced macrophage activation that covers the principle regulatory motifs. Based on that, we propose a simplified model with a reduced number of states and parameters that allows estimation of transcription factor activity from gene expression data and can be easily extended to describe the full spectrum of gene regulation in LPS-activated macrophages.