Selective downregulation of retinoic acid-inducible gene I within the intestinal epithelial compartment in Crohn's disease.

BACKGROUND: A defective innate immune response may contribute to the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC). Employing a global gene expression analysis, this study was aimed at identifying specifically regulated genes within the epithelial compartment in inflammatory bowel disease (IBD). METHODS: The epithelial fraction of human ileal mucosa samples from surgical specimens was obtained by laser microdissection. Gene expression was examined by global expression profiling (n = 18, Affymetrix), quantitative reverse-transcription polymerase chain reaction (RT-PCR) (n = 35), immunoblot analysis (n = 9), and immunohistochemistry (n = 25). RESULTS: Global expression profiling revealed a pronounced downregulation of the retinoic acid-inducible gene I (RIG-I) within the epithelial layer of the ileum in patients with CD but not with UC. The downregulation of RIG-I was confirmed by quantitative RT-PCR, immunoblot analysis, and immunohistochemistry. CONCLUSIONS: Epithelial downregulation of RIG-I, a known pattern recognition receptor for viral components, might contribute to alterations of the innate mucosal immune response, particularly in CD.

Reduced hydrophobicity of the colonic mucosal surface in ulcerative colitis as a hint at a physicochemical barrier defect.

PURPOSE: There is increasing evidence that a defect of the gastrointestinal mucosal barrier is important for the development of inflammatory bowel diseases (IBD). The hydrophobicity of the colonic mucosal surface is a measure of its resistance to luminal antigens, e.g. of bacterial origin. Therefore, the purpose of this study was to determine this parameter in patients suffering from IBD. METHODS: Nineteen patients with ulcerative colitis (UC), ten patients with Crohn's disease (CD) and 20 controls were examined. All underwent colonic surgery at the University Hospital Heidelberg. Clinical disease activity was determined. From every subject, colonic tissue specimens were obtained, and hydrophobicity of the mucosal surface was determined with a goniometer by multiple plateau contact angle measurements. Histological evaluation of disease activity was performed in directly adjacent tissue specimens. RESULTS: Hydrophobicity of the colonic mucosal surface, expressed as plateau contact angles, was significantly reduced in patients with UC (mean ± SEM, 47.8° ± 3.4°) compared to those with CD (72.0° ± 5.2°) and controls (72.5° ± 5.6°; over-all P = 0.0004; UC versus controls, P < 0.001; UC versus CD, P < 0.05; CD versus controls, P > 0.05). Between mucosal hydrophobicity and clinical disease activity, as well as mucosal hydrophobicity and histological disease activity, no significant correlation was found. CONCLUSIONS: The results suggest a defective physicochemical barrier as an essential factor in the pathogenesis of UC, but not CD. The fact that no correlation was found between mucosal hydrophobicity and disease activity may indicate that the loss of mucosal hydrophobicity in UC is not exclusively a secondary effect due to inflammation.

Serotonin receptor diversity in the human colon: Expression of serotonin type 3 receptor subunits 5-HT3C, 5-HT3D, and 5-HT3E.

Since the first description of 5-HT3 receptors more than 50 years ago, there has been speculation about the molecular basis of their receptor heterogeneity. We have cloned the genes encoding novel 5-HT3 subunits 5-HT3C, 5-HT3D, and 5-HT3E and have shown that these subunits are able to form functional heteromeric receptors when coexpressed with the 5-HT3A subunit. However, whether these subunits are actually expressed in human tissue remained to be confirmed. In the current study, we performed immunocytochemistry to locate the 5-HT3A as well as the 5-HT3C, 5-HT3D, and 5-HT3E subunits within the human colon. Western blot analysis was used to confirm subunit expression, and RT-PCR was employed to detect transcripts encoding 5-HT3 receptor subunits in microdissected tissue samples. This investigation revealed, for the first time, that 5-HT3C, 5-HT3D, and 5-HT3E subunits are coexpressed with 5-HT3A in cell bodies of myenteric neurons. Furthermore, 5-HT3A and 5-HT3D were found to be expressed in submucosal plexus of the human large intestine. These data provide a strong basis for future studies of the roles that specific 5-HT3 receptor subtypes play in the function of the enteric and central nervous systems and the contribution that specific 5-HT3 receptors make to the pathophysiology of gastrointestinal disorders such as irritable bowel syndrome and dyspepsia.

Primary chondrosarcoma of the kidney: case report and review of the literature.

We present a case of primary renal chondrosarcoma, its diagnosis and management.

DMBT1 functions as pattern-recognition molecule for poly-sulfated and poly-phosphorylated ligands.

Deleted in malignant brain tumors 1 (DMBT1) is a secreted glycoprotein displaying a broad bacterial-binding spectrum. Recent functional and genetic studies linked DMBT1 to the suppression of LPS-induced TLR4-mediated NF-kappaB activation and to the pathogenesis of Crohn's disease. Here, we aimed at unraveling the molecular basis of its function in mucosal protection and of its broad pathogen-binding specificity. We report that DMBT1 directly interacts with dextran sulfate sodium (DSS) and carrageenan, a structurally similar sulfated polysaccharide, which is used as a texturizer and thickener in human dietary products. However, binding of DMBT1 does not reduce the cytotoxic effects of these agents to intestinal epithelial cells in vitro. DSS and carrageenan compete for DMBT1-mediated bacterial aggregation via interaction with its bacterial-recognition motif. Competition and ELISA studies identify poly-sulfated and poly-phosphorylated structures as ligands for this recognition motif, such as heparansulfate, LPS, and lipoteichoic acid. Dose-response studies in Dmbt1(-/-) and Dmbt1(+/+) mice utilizing the DSS-induced colitis model demonstrate a differential response only to low but not to high DSS doses. We propose that DMBT1 functions as pattern-recognition molecule for poly-sulfated and poly-phosphorylated ligands providing a molecular basis for its broad bacterial-binding specificity and its inhibitory effects on LPS-induced TLR4-mediated NF-kappaB activation.

Prognostic value of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and TRAIL receptors in renal cell cancer.

PURPOSE: The death ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and its receptors (TRAIL-R) are involved in immune surveillance and tumor development. Here, we studied a possible association between the expression of TRAIL/TRAIL-Rs and the prognosis in patients with renal cell carcinomas (RCC). EXPERIMENTAL DESIGN: A tissue microarray containing RCC tumor tissue samples and corresponding normal tissue samples from 838 patients was generated. Expression of TRAIL and TRAIL-Rs was examined by immunohistochemistry and the effect of TRAIL and TRAIL-R expression on disease-specific survival was assessed. RESULTS: High TRAIL-R2 expression levels were associated with high-grade RCCs (P < 0.001) and correlated negatively with disease-specific survival (P = 0.01). Similarly, high TRAIL expression was associated with a shorter disease-specific survival (P = 0.01). In contrast, low TRAIL-R4 expression was associated with high-stage RCCs (P < 0.001) as well as with the incidence of distant metastasis (P = 0.03) and correlated negatively with disease-specific survival (P = 0.02). In patients without distant metastasis, multivariate Cox regression analyses revealed that TRAIL-R2 and TRAIL are independent prognostic factors for cancer-specific survival (in addition to tumor extent, regional lymph node metastasis, grade of malignancy, and type of surgery). CONCLUSION: High TRAIL-R2, high TRAIL, and low TRAIL-R4 expression levels are associated with a worse disease-specific survival in patients with RCCs. Therefore, the assessment of TRAIL/TRAIL-R expression offers valuable prognostic information that could be used to select patients for adjuvant therapy studies. Moreover, our findings are of relevance for a potential experimental therapeutic administration of TRAIL-R agonists in patients with RCCs.

CT and endoscopic ultrasound in comparison to endoluminal MRI: preliminary results in staging gastric carcinoma.

PURPOSE: To prospectively compare diagnostic parameters of a newly developed endoluminal MRI (endo-MRI) concept with endoscopic ultrasound (EUS) and hydro-computer tomography (Hydro-CT) in T-staging of gastric carcinoma on one patient collective. MATERIAL AND METHODS: 28 consecutive patients (11 females, 17 males, age range 46-87 years, median 67 years) referred for surgery due to a gastric malignancy were included. Preoperative staging by EUS was performed in 14 cases and by Hydro-CT in 14 cases within a time frame of 2 weeks. Ex vivo endo-MRI examination of gastric specimens was performed directly after gastrectomy within a time interval of 2-3h. EUS data were acquired from the clinical setting whereas Hydro-CT and endo-MRI data were evaluated in blinded fashion by two experienced radiologists and one surgeon well experienced in EUS on gastric carcinomas. RESULTS: Histopathology resulted in 4 pT1, 17 pT2, 3 pT3 and 2 pT4 carcinomas with 2 gastric lymphomas which were excluded. Overall accuracy for endo-MRI was 75% for T-Staging of the 26 carcinomas. EUS achieved 42.9% accuracy; endo-MRI in this subgroup was accurate in 71.4%. Hydro-CT was correct in 28.6%, accuracy for endo-MRI in this subgroup was 71.4%. CONCLUSION: The direct comparison of all three modalities on one patient collective shows that endo-MRI is able to achieve adequate staging results in comparison with clinically accepted methods like EUS and Hydro-CT in classifying the extent of tumor invasion into the gastric wall. However the comparison is limited as we compared in vivo routine clinical data with experimental ex vivo data. Future investigations need to show if the potential of endo-MRI can be transferred into a clinical in vivo setting.

High nuclear Livin expression is a favourable prognostic indicator in renal cell carcinoma.

OBJECTIVES: To assess the protein expression of Livin, an apoptosis inhibitor, in renal cell carcinoma (RCC) and to determine its prognostic relevance. PATIENTS AND METHODS: Immunohistochemical staining for Livin was performed in tissue microarrays (TMAs), including tumour tissue cores, from patients with RCC who had undergone renal surgery. In 682 TMAs cytoplasmatic staining intensity and nuclear staining quantity were evaluated, and the association of Livin expression with progression-free survival (PFS) and cancer-specific survival (CSS) was analysed with a multivariate Cox regression model. RESULTS: Over a median (range) follow-up of 5.2 (0-16.1) years, 204 patients (28%) had died from their disease. The CSS rates at 1 and 5 years for the entire cohort was 88% and 71%. Cytoplasmatic Livin staining was absent in 516 (76%) specimens; staining was positive in 166 (24%) specimens. Weak nuclear Livin staining (25%) nuclear Livin expression was a favourable independent predictor of PFS and CSS even after adjusting for tumour stage, Fuhrman grade, age, sex and Karnofsky severity rating. Cytoplasmatic Livin expression did not offer additional prognostic information. CONCLUSION: High nuclear Livin expression is a favourable independent predictor of PFS and CSS in patients with RCC.

Sexual pseudo-precocity caused by a somatic activating mutation of the LH receptor preceding true sexual precocity.

AIM: We describe the clinical features of a 6-year-old boy with sexual precocity caused by a somatic activating mutation of the luteinizing hormone (LH) receptor gene preceding gonadotropin-releasing hormone (GnRH)-dependent sexual precocity. STUDY DESIGN: Genomic DNA was extracted from the right testis and from the peripheral leukocytes followed by DNA amplification and sequencing of the LH receptor gene. We described the clinical characteristics including anthropometric parameters, bone age, and endocrine evaluation when the boy presented with sexual precocity. These data were compared with the clinical and hormonal evaluation after orchiectomy preceding GnRH-dependent sexual precocity and after subsequent treatment with GnRH agonist. RESULTS: No mutation was found in the sequence of the LH receptor gene extracted from peripheral leukocytes. Interestingly, sequencing of the tumor LH receptor gene revealed a heterozygous mutation in exon 11 encoding a replacement of Asp(578)His. Despite normalization of plasma testosterone, true precocious puberty was triggered within a year. CONCLUSIONS: Inmales with GnRH-independent sexual precocity the presence of small testicular Leydig cell tumorous lesions harboring a somatic mutation of the LH receptor gene should be considered. A close follow-up of affected patients should be instigated in order to monitor recurrence or subsequent true precocity.

Decoy receptor 3 is a prognostic factor in renal cell cancer.

BACKGROUND: Decoy receptor 3 (DcR3) is a soluble protein that binds to and inactivates the death ligand CD95L. Here, we studied a possible association between DcR3 expression and prognosis in patients with renal cell carcinomas (RCCs). METHODS: A tissue microarray containing RCC tumor tissue samples and corresponding normal tissue samples was generated. Decoy receptor 3 expression in tumors of 560 patients was examined by immunohistochemistry. The effect of DcR3 expression on disease-specific survival and progression-free survival was assessed using univariate analysis and multivariate Cox regression analysis. Decoy receptor 3 serum levels were determined by ELISA. FINDINGS: High DcR3 expression was associated with high-grade (P = .005) and high-stage (P = .048) RCCs. The incidence of distant metastasis (P = .03) and lymph node metastasis (P = .002) was significantly higher in the group with high DcR3 expression. Decoy receptor 3 expression correlated negatively with disease-specific survival (P < .001) and progression-free survival (P < .001) in univariate analyses. A multivariate Cox regression analysis retained DcR3 expression as an independent prognostic factor that outperformed the Karnofsky performance status. In patients with high-stage RCCs expressing DcR3, the 2-year survival probability was 25%, whereas in patients with DcR3-negative tumors, the survival probability was 65% (P < .001). Moreover, DcR3 serum levels were significantly higher in patients with high-stage localized disease (P = .007) and metastatic disease (P = .001). INTERPRETATION: DcR3 expression is an independent prognostic factor of RCC progression and mortality. Therefore, the assessment of DcR3 expression levels offers valuable prognostic information that could be used to select patients for adjuvant therapy studies.

Clinical relevance of mutations in the Wilms tumor suppressor 1 gene WT1 and the cadherin-associated protein beta1 gene CTNNB1 for patients with Wilms tumors: results of long-term surveillance of 71 patients from International Society of Pediatric Oncology Study 9/Society for Pediatric Oncology.

BACKGROUND: Mutations in the Wilms tumor (WT) suppressor 1 gene (WT1) and the cadherin-associated protein beta1 gene (CTNNB1) are found predominantly in stromal type WT, defining a genetic subgroup. The clinical relevance of these mutations remains to be determined. METHODS: A long-term follow-up study was performed for 71 patients (International Society of Pediatric Oncology Study 9/Society for Pediatric Oncology; n = 77 tumors) with known molecular genetic status. Eight patients had bilateral disease, including 2 patients with a WT in both kidneys and 5 patients with a WT in 1 kidney and nephrogenic rests (NRs) in the other kidney. The response to preoperative chemotherapy, relapses, metastases, metachronous tumor development, and deaths were evaluated with a median follow-up of 12 years and 4 months. RESULTS: Nineteen patients (n = 24 tumors) had WT1 mutations, and 16 were constitutional mutations. Three patients with germline mutations had second tumor events: Two patients developed a WT in the kidney with NRs 3 years and 11 years after the first tumor; and 1 patient developed second tumors after 2 years, 1 in the kidney with a previous WT and 1 in the kidney with a previous NR. Eighteen of the WT1 mutant tumors were analyzed for CTNNB1 mutations, and all had mutations. A poor volumetric response (progression and <50% reduction) was observed in all patients who had tumors with a WT1 mutation and in 23 of 52 nonmutant tumors. CONCLUSIONS: Patients with WT1 germline mutations had an increased risk for bilateral disease and second tumor events. Therefore, the authors concluded that tumor surveillance until adulthood should be considered. Although tumors with both WT1 and CTNNB1 mutations had a poor volumetric response, there was no significant difference in overall survival in this cohort of patients with and without WT1 mutations.

High-mobility group box-1 in ischemia-reperfusion injury of the heart.

BACKGROUND: High-mobility group box-1 (HMGB1) is a nuclear factor released by necrotic cells and by activated immune cells. HMGB1 signals via members of the toll-like receptor family and the receptor for advanced glycation end products (RAGE). Although HMGB1 has been implicated in ischemia/reperfusion (I/R) injury of the liver and lung, its role in I/R injury of the heart remains unclear. METHODS AND RESULTS: Here, we demonstrate that HMGB1 acts as an early mediator of inflammation and organ damage in I/R injury of the heart. HMGB1 levels were already elevated 30 minutes after hypoxia in vitro and in ischemic injury of the heart in vivo. Treatment of mice with recombinant HMGB1 worsened I/R injury, whereas treatment with HMGB1 box A significantly reduced infarct size and markers of tissue damage. In addition, HMGB1 inhibition with recombinant HMGB1 box A suggested an involvement of the mitogen-activated protein kinases jun N-terminal kinase and extracellular signal-regulated kinase 1/2, as well as the nuclear transcription factor nuclear factor-kappaB in I/R injury. Interestingly, infarct size and markers of tissue damage were not affected by administration of recombinant HMGB1 or HMGB1 antagonists in RAGE(-/-) mice, which demonstrated significantly reduced damage in reperfused hearts compared with wild-type mice. Coincubation studies using recombinant HMGB1 in vitro induced an inflammatory response in isolated macrophages from wild-type mice but not in macrophages from RAGE(-/-) mice. CONCLUSIONS: HMGB1 plays a major role in the early event of I/R injury by binding to RAGE, resulting in the activation of proinflammatory pathways and enhanced myocardial injury. Therefore, blockage of HMGB1 might represent a novel therapeutic strategy in I/R injury.

A prominent role for mucosal cystine/cysteine metabolism in intestinal immunoregulation.

BACKGROUND & AIMS: T-cell receptor reactivity of intestinal lamina propria T cells (LP-T) critically depends on the capacity of local accessory cells to secrete cysteine. For T cells, cysteine is the limiting precursor for glutathione synthesis, a prerequisite for antigen-dependent proliferation. We aimed to determine the role of the redoxactive microenvironment for hyporeactivity of LP-T in normal human gut vs hyperreactivity of LP-T in inflammatory bowel disease. METHODS: Parameters relevant to cysteine production, determined as acid-soluble thiol, by intestinal lamina propria macrophages (LP-MO) vs peripheral blood monocytes were investigated (L-[(35)S]cystine uptake via system x(c)(-), messenger RNA, and protein expression of the cystine transporter subunit xCT). Glutathione levels in LP-T and peripheral blood T cells were analyzed both spectrophotometrically and by immunofluorescent staining in situ and in vitro. RESULTS: LP-MO from normal gut, unlike peripheral blood monocytes, are unable to take up cystine, which is due to a deficient expression of the transporter xCT in situ and in vitro. As a consequence, LP-MO do not secrete cysteine. The glutathione content in LP-T from normal gut is <50% of that in autologous peripheral blood T cells. In contrast, in inflammatory bowel disease, CD14(+)CD68(+) LP-MO express xCT and secrete substantial amounts of cysteine upon stimulation, which results in high glutathione levels and full T-cell receptor reactivity in LP-T. CONCLUSIONS: The antioxidative microenvironment of LP-T in inflammatory bowel disease and the prooxidative microenvironment in normal gut explain the differential T-cell receptor reactivities.

Phosphatidylcholine for steroid-refractory chronic ulcerative colitis: a randomized trial.

BACKGROUND: Although long-term steroid treatment is discouraged in ulcerative colitis, alternatives are lacking when therapy with immunosuppressant drugs fails. An insufficient level of phosphatidylcholine in colonic mucus is a possible pathogenetic factor for ulcerative colitis. OBJECTIVE: To see whether steroid withdrawal is easier with retarded-release phosphatidylcholine or placebo in adults with chronic steroid-refractory ulcerative colitis. DESIGN: Randomized, double-blind, placebo-controlled trial conducted from March 2003 to January 2006. SETTING: University Hospital Heidelberg, a referral center for inflammatory bowel disease. PATIENTS: 60 patients with chronic steroid-refractory ulcerative colitis and high clinical and endoscopic disease activity indexes (score > or =5). INTERVENTION: Phosphatidylcholine or cellulose placebo was ingested 4 times daily for 12 weeks for a total dosage of 2 g/d. The follow-up rate was 97%. MEASUREMENTS: The number of patients achieving complete steroid withdrawal and either a low clinical activity index (< or =3) or improvement in the clinical activity index of 50% or more. RESULTS: The primary end point was achieved in 15 of 30 (50%) phosphatidylcholine recipients and in 3 of 30 (10%) placebo recipients (difference, 40% [95% CI, 19% to 61%]; P = 0.002). Twenty-four phosphatidylcholine recipients (80%) and 3 (10%) placebo recipients discontinued steroid therapy without disease exacerbation (difference, 70% [CI, 52% to 88%]; P <0.001). Mild bloating was a common adverse event. LIMITATIONS: The sample size was small, and the study was of short duration. CONCLUSION: Phosphatidylcholine reduced corticosteroid dependence more than placebo in patients with chronic steroid-refractory ulcerative colitis. The next step is long-term trials to evaluate the sustainability of steroid withdrawal in these patients. ClinicalTrials.gov registration number: NCT00259545.

DMBT1 confers mucosal protection in vivo and a deletion variant is associated with Crohn's disease.

BACKGROUND & AIMS: Impaired mucosal defense plays an important role in the pathogenesis of Crohn's disease (CD), one of the main subtypes of inflammatory bowel disease (IBD). Deleted in malignant brain tumors 1 (DMBT1) is a secreted scavenger receptor cysteine-rich protein with predominant expression in the intestine and has been proposed to exert possible functions in regenerative processes and pathogen defense. Here, we aimed at analyzing the role of DMBT1 in IBD. METHODS: We studied DMBT1 expression in IBD and normal tissues by quantitative reverse transcription-polymerase chain reaction, immunohistochemistry, and mRNA in situ hybridization. Genetic polymorphisms within DMBT1 were analyzed in an Italian IBD case-control sample. Dmbt1(-/-) mice were generated, characterized, and analyzed for their susceptibility to dextran sulfate sodium-induced colitis. RESULTS: DMBT1 levels correlate with disease activity in inflamed IBD tissues. A highly significant fraction of the patients with IBD displayed up-regulation of DMBT1 specifically in the intestinal epithelial surface cells and Paneth cells. A deletion allele of DMBT1 with a reduced number of scavenger receptor cysteine-rich domain coding exons is associated with an increased risk of CD (P = .00056; odds ratio, 1.75) but not for ulcerative colitis. Dmbt1(-/-) mice display enhanced susceptibility to dextran sulfate sodium-induced colitis and elevated Tnf, Il6, and Nod2 expression levels during inflammation. CONCLUSIONS: DMBT1 may play a role in intestinal mucosal protection and prevention of inflammation. Impaired DMBT1 function may contribute to the pathogenesis of CD.

Sulfated glycosphingolipid as mediator of phagocytosis: SM4s enhances apoptotic cell clearance and modulates macrophage activity.

Sulfoglycolipids are present on the surface of a variety of cells. The sulfatide SM4s is increased in lung, renal, and colon cancer and is associated with an adverse prognosis, possibly due to a low immunoreactivity of the tumor. As macrophages significantly contribute to the inflammatory infiltrate in malignancies, we postulated that SM4s may modulate macrophage function. We have investigated the effect of SM4s on the uptake of apoptotic tumor cells, macrophage cytokine profile, and receptor expression. Using flow cytometry and microscopic analyses, we found that coating apoptotic murine carcinoma cells from the colon and kidney with SM4s promoted their phagocytosis by murine macrophages up to 3-fold ex vivo and in vivo. This increased capacity was specifically inhibited by preincubation of macrophages with oxidized or acetylated low density lipoprotein and maleylated albumin, indicating involvement of scavenger receptors in this interaction. The uptake of SM4s-coated apoptotic cells significantly enhanced macrophage production of TGF-beta1, expression of P-selectin, and secretion of IL-6. These data suggest that SM4s within tumors may promote apoptotic cell removal and alter the phenotype of tumor-associated macrophages.

Regulation of enterocyte apoptosis by acyl-CoA synthetase 5 splicing.

BACKGROUND AND AIMS: The constant renewal of enterocytes along the crypt-villus axis (CVA) of human small intestine is due to cell-inherent changes resulting in the apoptotic cell death of senescent enterocytes. The aim of the present study was to examine underlying molecular mechanisms of the cell death at the villus tip. METHODS: Characterization of human acyl-coenzyme A (CoA) synthetase 5 (ACSL5) was performed by cloning, recombinant protein expression, biochemical approaches, and several functional and in situ analyses. RESULTS: Our data show that different amounts of acyl-CoA synthetase 5-full length (ACSL5-fl) and a so far unknown splice variant lacking exon 20 (ACSL5-Delta 20) are found in human enterocytes. In contrast with the splice variant ACSL5-Delta 20, recombinant and purified ACSL5-fl protein is active at a highly alkaline pH. Over expression of ACSL5-fl protein is associated with a decrease of the anti-apoptotic FLIP protein in a ceramide-dependent manner and an increased cell-surface expression of the death receptor TRAIL-R1. Expression analyses revealed that the ACSL5-fl/ACSL5-Delta 20 ratio increases along the CVA, thereby sensitizing ACSL5-fl-dominated cells at the villus tip to the death ligand TRAIL, which is corroborated by functional studies with human small intestinal mucosal samples and an immortalized human small intestinal cell line. CONCLUSIONS: Our results suggest an ACSL5-dependent regulatory mechanism that contributes to the cellular renewal along the CVA in human small intestine. Deregulation of the ACSL5-fl/ACSL5-Delta 20 homeostasis in the maturation and shedding of cells along the CVA might also be of relevance for the development of intestinal neoplasia.

Endoscopic posterior mesorectal resection as an option to combine local treatment of early stage rectal cancer with partial mesorectal lymphadenectomy.

BACKGROUND AND AIMS: Low anterior resection and abdominoperineal resection with total mesorectal excision are the standard treatment in patients with low rectal cancer. Rectal resection remains a surgical intervention with considerable morbidity and long-term impairment of quality of life. Local excision of low rectal cancer is regarded as an alternative to radical surgery; however, occurrence of lymph node metastasis even in patients with highly differentiated early-stage rectal cancer may be underestimated. PATIENTS AND RESULTS: In two patients with T1 rectal cancer, minimal-invasive partial excision of the mesorectum was performed after transanal excision of the tumor. The postoperative course was uneventful in both patients. Patients left the hospital on the fourth and fifth postoperative day without any complaints. In one patient, histo-pathological workup revealed a lymph node metastasis in the specimen. DISCUSSION: The technique of "Endoscopic posterior mesorectal resection" represents an interesting option in the surgical treatment of rectal cancer, as it allows for the first time an organ preserving resection of local lymph nodes in the small pelvis. It may evolve as an efficient new staging procedure to identify patients with metastatic disease who may benefit from multimodal treatment or extended surgery.