Dissecting the genetic heterogeneity of gastric cancer

BACKGROUND

Gastric cancer (GC) is clinically heterogenous according to location (cardia/non-cardia) and histopathology (diffuse/intestinal). We aimed to characterize the genetic risk architecture of GC according to its subtypes. Another aim was to examine whether cardia GC and oesophageal adenocarcinoma (OAC) and its precursor lesion Barrett's oesophagus (BO), which are all located at the gastro-oesophageal junction (GOJ), share polygenic risk architecture.

METHODS

We did a meta-analysis of ten European genome-wide association studies (GWAS) of GC and its subtypes. All patients had a histopathologically confirmed diagnosis of gastric adenocarcinoma. For the identification of risk genes among GWAS loci we did a transcriptome-wide association study (TWAS) and expression quantitative trait locus (eQTL) study from gastric corpus and antrum mucosa. To test whether cardia GC and OAC/BO share genetic aetiology we also used a European GWAS sample with OAC/BO.

FINDINGS

Our GWAS consisting of 5816 patients and 10,999 controls highlights the genetic heterogeneity of GC according to its subtypes. We newly identified two and replicated five GC risk loci, all of them with subtype-specific association. The gastric transcriptome data consisting of 361 corpus and 342 antrum mucosa samples revealed that an upregulated expression of MUC1, ANKRD50, PTGER4, and PSCA are plausible GC-pathomechanisms at four GWAS loci. At another risk locus, we found that the blood-group 0 exerts protective effects for non-cardia and diffuse GC, while blood-group A increases risk for both GC subtypes. Furthermore, our GWAS on cardia GC and OAC/BO (10,279 patients, 16,527 controls) showed that both cancer entities share genetic aetiology at the polygenic level and identified two new risk loci on the single-marker level.

INTERPRETATION

Our findings show that the pathophysiology of GC is genetically heterogenous according to location and histopathology. Moreover, our findings point to common molecular mechanisms underlying cardia GC and OAC/BO.

FUNDING

German Research Foundation (DFG).

Mismatch repair deficiency, chemotherapy and survival for resectable gastric cancer: an observational study from the German staR cohort and a meta-analysis

PURPOSE

In a post hoc analysis of the MAGIC trial, patients with curatively resected gastric cancer (GC) and mismatch repair (MMR) deficiency (MMRd) had better median overall survival (OS) when treated with surgery alone but worse median OS when treated with additional chemotherapy. Further data are required to corroborate these findings.

METHODS

Between April 2013 and December 2018, 458 patients with curatively resected GC, including cancers of the esophagogastric junction Siewert type II and III, were identified in the German centers of the staR consortium. Tumor sections were assessed for expression of MLH1, MSH2, MSH6 and PMS2 by immunohistochemistry. The association between MMR status and survival was assessed. Similar studies published up to January 2021 were then identified in a MEDLINE search for a meta-analysis.

RESULTS

MMR-status and survival data were available for 223 patients (median age 66 years, 62.8% male), 23 patients were MMRd (10.3%). After matching for baseline clinical characteristics, median OS was not reached in any subgroup. Compared to perioperative chemotherapy, patients receiving surgery alone with MMRd and MMRp had a HR of 0.67 (95% CI 0.13-3.37, P = 0.63) and 1.44 (95% CI 0.66-3.13, P = 0.36), respectively. The meta-analysis included pooled data from 385 patients. Compared to perioperative chemotherapy, patients receiving surgery alone with MMRd had an improved OS with a HR of 0.36 (95% CI 0.14-0.91, P = 0.03), whereas those with MMRp had a HR of 1.18 (95% CI 0.89-1.58, P = 0.26).

CONCLUSION

Our data support a positive prognostic effect for MMRd in GC patients treated with surgery only and a differentially negative prognostic effect in patients treated with perioperative chemotherapy. MMR status determined by preoperative biopsies may be used as a predictive biomarker to select patients for perioperative chemotherapy in curatively resectable GC.

Different Prevalence of Alarm, Dyspeptic and Reflux Symptoms in Patients with Cardia and Non-cardia Gastric Cancer

BACKGROUND AND AIMS

Symptoms of patients with gastric cancer (GC) are often unspecific and differences in symptoms between patients with cardia and non-cardia GC have been poorly investigated. We aimed to characterize symptoms of patients with cardia and non-cardia GC.

METHODS

Patients with cardia (Siewert type II and III) and non-cardia GC were recruited in the German multicenter cohort of the Gastric Cancer Research (staR) study between 2013 and 2017. Alarm, dyspeptic and reflux symptoms at the time of presentation were documented using a self-administered questionnaire.

RESULTS

A completed self-administered questionnaire was available for 568/759 recruited patients (132 cardia GC, 436 non-cardia GC, male 61%, mean age 64 years). Dyspeptic symptoms were more common in patients with non-cardia GC (69.0 vs. 54.5%, p=0.0024). Cardia GC patients reported more frequently alarm symptoms (69.7 vs. 44.7%, p<0.0001), and were more likely to have Union for International Cancer Control (UICC) stage III-IV (54.1vs. 38.9%, p=0.0034). Especially, dysphagia and weight loss were more common in patients with cardia GC (49.2 vs. 6.4 %, p<0.0001 and 37.1 vs. 25.7%, p=0.02, respectively). No differences between the two groups were observed with respect to reflux symptoms. Patients with alarm symptoms were more likely to have UICC stage III-IV at presentation (69.4 vs. 42.9%, p<0.0001).

CONCLUSIONS

In clinical practice the symptom pattern at presentation may serve as a hint for tumor localization. Despite the fact that they are common in the general population, dyspeptic symptoms offer a chance for earlier GC detection. Thus, in patients with dyspeptic symptoms who fail empiric approaches, endoscopy should not be delayed.

Gastric cancer in autoimmune gastritis: A case-control study from the German centers of the staR project on gastric cancer research

Objectives

Patients with autoimmune gastritis (AIG) are reported to have an increased risk of developing gastric cancer (GC). In this study, we assess the characteristics and outcomes of GC patients with AIG in a multicenter case-control study.

Methods

Between April 2013 and May 2017, patients with GC, including cancers of the esophagogastric junction (EGJ) Siewert type II and III, were recruited. Patients with histological characteristics of AIG were identified and matched in a 1:2 fashion for age and gender to GC patients with no AIG. Presenting symptoms were documented using a self-administered questionnaire.

Results

Histological assessment of gastric mucosa was available for 572/759 GC patients. Overall, 28 (4.9%) of GC patients had AIG (67 ± 9 years, female-to-male ratio 1.3:1). In patients with AIG, GC was more likely to be localized in the proximal (i.e. EGJ, fundus, corpus) stomach (odds ratio (OR) 2.7, 95% confidence interval (CI) 1.0–7.1). In GC patients with AIG, pernicious anemia was the leading clinical sign (OR 22.0, 95% CI 2.6–187.2), and the most common indication for esophagogastroduodenoscopy (OR 29.0, 95% CI 7.2–116.4). GC patients with AIG were more likely to present without distant metastases (OR 6.2, 95% CI 1.3–28.8) and to be treated with curative intention (OR 3.0, 95% CI 1.0–9.0). The five-year survival rates with 95% CI in GC patients with and with no AIG were 84.7% (83.8–85.6) and 53.5% (50.9–56.1), respectively (OR 0.25, 95% CI 0.08–0.75, p = 0.001).

Conclusions

Pernicious anemia leads to earlier diagnosis of GC in AIG patients and contributes significantly to a better clinical outcome.

Tumor budding outperforms ypT and ypN classification in predicting outcome of rectal cancer after neoadjuvant chemoradiotherapy

Background

Budding is a complementary prognostic factor for colorectal cancer. In this study, we aimed to clarify the role of tumor budding in rectal cancer patients after preoperative chemoradiotherapy.

Methods

A total of 124 patients with rectal cancer treated with neoadjuvant chemoradiotherapy and consecutive surgery were included. Surgical specimens were evaluated for budding and routine clinicopathological features. Budding was evaluated on hematoxylin and eosin (H&E)-stained slides and by cytokeratin immunohistochemical (IHC) staining.

Results

A budding rate of 36.9% (n = 38) by H&E and 55.6% (n = 55) by IHC was observed. Budding was significantly associated with a high ypT and ypN status, poor differentiation, and low degrees of tumor regression. Moreover, budding was strongly predictive of a worse patient outcome, as measured by tumor recurrence or death. In multivariate analyses, budding remained the only significant parameter for overall survival and was even superior to the ypT and ypN status (budding in H&E: hazard ratio (HR) 2.72, 95% confidence interval (95% CI) 1.15–6.44, p = 0.023; budding in IHC: HR 5.19, 95% CI 1.62–16.61, p = 0.006).

Conclusion

Budding is a strong prognostic predictor of survival in rectal cancer patients after neoadjuvant therapy. A standardized evaluation of tumor budding after neoadjuvant therapy may thus aid in risk stratification and guide the clinical management of patients with rectal cancer. Immunostaining can help to enhance the diagnostic accuracy and prognostic significance.

Evidence for PTGER4, PSCA, and MBOAT7 as risk genes for gastric cancer on the genome and transcriptome level

Genetic associations between variants on chromosome 5p13 and 8q24 and gastric cancer (GC) have been previously reported in the Asian population. We aimed to replicate these findings and to characterize the associations at the genome and transcriptome level. We performed a fine‐mapping association study in 1926 GC patients and 2012 controls of European descent using high dense SNP marker sets on both chromosomal regions. Next, we performed expression quantitative trait locus (eQTL) analyses using gastric transcriptome data from 143 individuals focusing on the GC associated variants. On chromosome 5p13 the strongest association was observed at rs6872282 (P = 2.53 × 10⁻⁰⁴) and on chromosome 8q24 at rs2585176 (P = 1.09 × 10⁻⁰⁹). On chromosome 5p13 we found cis‐eQTL effects with an upregulation of PTGER4 expression in GC risk allele carrier (P = 9.27 × 10⁻¹¹). On chromosome 8q24 we observed cis‐eQTL effects with an upregulation of PSCA expression in GC risk allele carrier (P = 2.17 × 10⁻⁴⁷). In addition, we found trans‐eQTL effects for the same variants on 8q24 with a downregulation of MBOAT7 expression in GC risk allele carrier (P = 3.11 × 10⁻⁰⁹). In summary, we confirmed and refined the previously reported GC associations at both chromosomal regions. Our data point to shared etiological factors between Asians and Europeans. Furthermore, our data imply an upregulated expression of PTGER4 and PSCA as well as a downregulated expression of MBOAT7 in gastric tissue as risk‐conferring GC pathomechanisms.

Nosokomiale Pneumonie

Nosokomiale Infektionen betreffen nach postoperativen Entzündungen von Wunden und Harnwegsinfektion am dritthäufigsten die unteren Atemwege. Die Pneumonie ist dabei die häufigste nosokomiale Atemwegsinfektion. Sie tritt überwiegend bei invasiv beatmeten Patienten auf. Zunehmend werden nosokomiale Infektionen durch multiresistente Keime hervorgerufen, was das Risiko einer inadäquaten initialen antiinfektiven Therapie erhöht. Die antiinfektive Therapie sollte bereits im Verdachtsfall begonnen werden. Die Diagnose ist im Verlauf kritisch zu überprüfen. Bestätigt sich eine nosokomiale Pneumonie nicht, sollte die antiinfektive Therapie vorzeitig beendet werden. Für die beatmungsassoziierte Pneumonie wurden verschiedene präventiv wirksame Maßnahmenbündel untersucht, mit deren Hilfe die Pneumonierate um über 50 % gesenkt werden konnte.

Poorly Differentiated Medullary Phenotype Predicts Poor Survival in Early Lymph Node-Negative Gastro-Esophageal Adenocarcinomas

BACKGROUND

5-year survival rate in patients with early adenocarcinoma of the gastro-esophageal junction or stomach (AGE/S) in Caucasian patients is reported to be 60-80%. We aimed to identify prognostic markers for patients with UICC-I without lymph-node involvement (N0).

METHODS

Clinical data and tissue specimen from patients with AGE/S stage UICC-I-N0, treated by surgery only, were collected retrospectively. Tumor size, lymphatic vessel or vein invasion, grading, classification systems (WHO, Lauren, Ming), expression of BAX, BCL-2, CDX2, Cyclin E, E-cadherin, Ki-67, TP53, TP21, SHH, Survivin, HIF1A, TROP2 and mismatch repair deficiency were analyzed using tissue microarrays and correlated with overall and tumor related survival.

RESULTS

129 patients (48 female) with a mean follow-up of 129.1 months were identified. 5-year overall survival was 83.9%, 5-year tumor related survival was 95.1%. Poorly differentiated medullary cancer subtypes (p<0.001) and positive vein invasion (p<0.001) were identified as risk factors for decreased overall-and tumor related survival. Ki-67 (p = 0.012) and TP53 mutation (p = 0.044) were the only immunohistochemical markers associated with worse overall survival but did not reach significance for decreased tumor related survival.

CONCLUSION

In the presented study patients with AGE/S in stage UICC-I-N0 had a better prognosis as previously reported for Caucasian patients. Poorly differentiated medullary subtype was associated with reduced survival and should be considered when studying prognosis in these patients.

Diagnostic confidence of run-off CT-angiography as the primary diagnostic imaging modality in patients presenting with acute or chronic peripheral arterial disease

Objectives

To investigate the reliability of CT-angiography of the lower extremities (run-off CTA) to derive a treatment decision in patients with acute and chronic peripheral artery disease (PAD).

Materials and Methods

314 patients referred for run-off CTA were includ-ed in this retrospective study. First, diagnostic confidence of run-off CTA to derive a treat-ment decision was assessed in an interdisciplinary vascular conference using a 2 point scale (sufficient or not sufficient diagnostic confidence) and compared with the image quality eval-uated by two readers in consensus in four different levels (abdominopelvic, thigh, calf, foot arteries). Second, reliability of treatment decision was verified in all patients undergoing re-vascularization therapy.

Results

Diagnostic confidence of run-off CTA to derive a treatment deci-sion was sufficient in all patients with acute and in 97% of patients (215/221) with chronic PAD, whereas the rate of run-off CTA with non-diagnostic image quality was considerably higher in the calf and foot level (acute vs. chronic; calf: 28% vs.17%; foot: 52% vs. 20%). Reliability of treatment decision was superior for patients with chronic (123/133 = 92%) than for patients with acute PAD (64/78 = 82%, P = 0.02).

Conclusion

Run-off CTA is a reliable imaging modality for primary diag-nostic work-up of patients with acute and chronic PAD.

[Safety of resection of symptomatic and asymptomatic Meckel's diverticulum and literature review]

BACKGROUND

Meckel's diverticulum (MD) is the most common diverticulum of the small bowel and an important finding in surgical practice. The aim of this study was to assess the safety of the resection of symptomatic and asymptomatic MD concerning postoperative complications. As MD are relatively rare, an overview of the literature is given.

PATIENTS AND METHODS

All patients with MD at the department at general surgery of the Charité - Campus Benjamin Franklin between 1996 and 2010 were assessed. An analysis for symptomatic and incidental MD was performed for incidence, indication, intraoperative findings, histology and postoperative outcome.

RESULTS

An MD was intraoperatively found in 71 of 29 682 patients (0.2 %). Of these, a symptomatic MD occurred in 26 patients (37 %). A symptomatic MD was causal in 6 of 7 patients with gastrointestinal bleeding (GIB, p = 0.005). All symptomatic MD and 30 (67 %) asymptomatic MD were resected. Ectopic gastric mucosa was found significantly more frequently in patients with symptomatic MD (p = 0.001). Patients with asymptomatic MD and resection had less complications as a trend (p = 0.057).

CONCLUSION

Ectopic mucosa is more frequent in symptomatic MD, especially in bleeding MD. MD should always be considered in GIB of unknown origin. Resection of incidental MD can be recommended in patients without contraindications such as peritonitis, cancer, ascites or immunosuppression.

Increased Pontin expression is a potential predictor for outcome in sporadic colorectal carcinoma

Colorectal cancer is one of the leading causes of cancer-related death worldwide. Molecular biomarkers could help to predict patient outcome and to identify patients who benefit from adjuvant therapy. Pontin and Reptin are ATPases which are involved in transcriptional regulation, DNA damage repair and regulation of cell proliferation. Many interaction partners of Pontin and Reptin such as β-catenin and c-myc are important factors in carcinogenesis. We hypothesized that Pontin and Reptin expression may be a negative predictor for survival in colorectal carcinoma. Specimens from 115 patients with primary colon adenocarcinomas UICC stage III and primary rectal adenocarcinomas UICC stage II and III curatively resected at the Department of Surgery, Charité Berlin, were evaluated. Clinical follow-up data were complete and mean follow-up time of patients was 51.8 months. We evaluated the expression of Pontin, Reptin and Ki-67 by immunohistochemistry. Patients with Pontin-positive carcinomas showed no differences in recurrence-free survival (p=0.109) and overall survival (p=0.197). There were no differences in Reptin-positive carcinomas and Ki-67-positive carcinomas in recurrence-free survival (p=0.443 and p=0.160) and overall survival (p=0.477 and p=0.687). Patients with Pontin-positive colorectal carcinomas receiving adjuvant therapy had a significantly worse recurrence-free survival (p=0.008) and overall survival (p=0.011) than Pontin-negative patients with adjuvant therapy. In UICC stage III, Pontin-positive colorectal carcinomas had a significantly worse recurrence-free survival (p=0.028). Pontin-positivity seems to be a negative predictor for response to adjuvant therapy in colorectal cancer patients and may help to identify patients with adverse outcome in advanced tumor stages.

Locally recurrent colorectal cancer: results of surgical therapy

PURPOSE

Up to 20 % of colorectal cancer patients develop recurrent disease despite standardized surgical techniques and multimodal treatment strategies. Radical resection is the central component of curative therapy in these cases. The aim of this study was to evaluate treatment results in patients with locoregionally recurrent colorectal cancer.

METHODS

From January 1995 to December 2007, surgery was performed for recurrent colorectal cancer in 82 patients who had undergone curative (R0) resection of their primary tumor. Assessment included patient, tumor and treatment characteristics, postoperative complications, and time without re-recurrence; recurrence-free and overall survival rates were calculated according to the Kaplan-Meier method.

RESULTS

Resection was performed in 60 of the 82 patients (73 %), repeat R0 resection in 52 % (31/60). Patients had a postoperative morbidity of 39 % (31/82), a relaparotomy rate of 13 % (11/82), and a lethality of 7 % (6/82). Forty-eight percent of all surgically-treated patients received a permanent stoma. Re-recurrence was seen in 52 % (16/31). R0 resection was associated with a 5-year survival rate of 35 % (11/31).

CONCLUSIONS

Extensive reinterventions often enable repeat R0 resection. Despite relevant morbidity, the lethality appears to be acceptable. Decisive for the prognosis is re-recurrence.

The Prognostic Impact of p53 Expression on Sporadic Colorectal Cancer Is Dependent on p21 Status

The prognostic value of p53 and p21 expression in colorectal cancer is still under debate. We hypothesize that the prognostic impact of p53 expression is dependent on p21 status. The expression of p53 and p21 was immunohistochemically investigated in a prospective cohort of 116 patients with UICC stage II and III sporadic colorectal cancer. The results were correlated with overall and recurrence-free survival. The mean observation period was 51.8 ± 2.5 months. Expression of p53 was observed in 72 tumors (63%). Overall survival was significantly better in patients with p53-positive carcinomas than in those without p53 expression (p = 0.048). No differences were found in recurrence-free survival (p = 0.161). The p53+/p21− combination was seen in 68% (n = 49), the p53+/p21+ combination in 32% (n = 23). Patients with p53+/p21− carcinomas had significantly better overall and recurrence-free survival than those with p53+/p21+ (p < 0.0001 resp. p = 0.003). Our data suggest that the prognostic impact of p53 expression on sporadic colorectal cancer is dependent on p21 status.

Management and results of complications after anterior resection with colonic pouch reconstruction for rectal cancer

AIM

Colonic J-pouch reconstruction is widely carried out during low anterior resection. The aim of this observational study was to describe the complications and evaluate the results of adverse event management.

METHOD

A total of 128 patients underwent an elective anterior resection with colorectal or coloanal J-pouch reconstruction for primary rectal cancer between January 1997 and December 2008.

RESULTS

The overall mortality was 1.6%. Three (2.3%) patients developed pouch necrosis, one of whom died. The rate of anastomotic leakage was 11.7%. Other major complications included intra-abdominal abscess (3.1%), haemorrhage (0.8%) and abdominal dihiscence (0.8%). In all cases of anastomotic leakage, the pouch was salvaged, with 80% of patients undergoing surgical revision with relaparotomy and transanal suture. Patients with pouch necrosis underwent relaparotomy with removal of the pouch and a terminal colostomy. In all cases of intra-abdominal abscess without anastomotic leakage, radiologically controlled percutaneous drainage was carried out.

CONCLUSION

Anal function can usually be saved after anastomotic leakage by salvage surgery without increase in mortality.

Epigenetic quantification of tumor-infiltrating T-lymphocytes

The immune system plays a pivotal role in tumor establishment. However, the role of T-lymphocytes within the tumor microenvironment as major cellular component of the adaptive effector immune response and their counterpart, regulatory T-cells (Treg), responsible for suppressive immune modulation, is not completely understood. This is partly due to the lack of reliable technical solutions for specific cell quantification in solid tissues. Previous reports indicated that epigenetic marks of immune cells, such as the Treg specifically demethylated region (TSDR) within the FOXP3 gene, may be exploited as robust analytical tool for Treg-quantification. Here, we expand the concept of epigenetic immunophenotyping to overall T-lymphocytes (oTL). This tool allows cell quantification with at least equivalent precision to FACS and is adoptable for analysis of blood and solid tissues. Based on this method, we analyse the frequency of Treg, oTL and their ratio in independent cohorts of healthy and tumorous ovarian, colorectal and bronchial tissues with 616 partly donor-matched samples. We find a shift of the median ratio of Treg-to-oTL from 3-8% in healthy tissue to 18-25% in all tumor entities. Epigenetically determined oTL frequencies correlate with the outcome of colorectal and ovarian cancers. Together, our data show that the composition of immune cells in tumor microenvironments can be quantitatively assessed by epigenetic measurements. This composition is disturbed in solid tumors, indicating a fundamental mechanism of tumor immune evasion. Epigenetic quantification of T-lymphocytes serves as independent clinical parameter for outcome prognosis.

The vasculitis in IBD is associated with the degree of inflammation

The role of vasculitis in the pathogenesis of IBD remains unclear. The aim of this study was to evaluate the detection rate of vasculitis in patients with IBD, its location in the intestinal wall layers and whether it occurs dependent of the degree of inflammation. Immunohistological staining with the endothelial cell marker CD31 and the pan-T cell marker CD3 was performed in 56 colonic specimens of Crohn's disease, in 43 of ulcerative colitis, and in 5 of colon cancer. Quantification of the degree of inflammation was done using a histological colitis score. There was no sign of vasculitis in the healthy intestinal wall layers. In Crohn's disease, specimens with minor inflammatory activity (score 0-2) disclosed no vasculitis. Vasculitis was observed in 82% of the specimens with an inflammatory degree of 3 and in 100% with an inflammatory degree of 4. Vasculitis was detected in all intestinal wall layers altered by inflammation. A direct association between vasculitis and granulomas was observed in only 5% of the specimens with an inflammatory degree of 4. All ulcerative colitis specimens evidenced an inflammatory degree between 2 and 4. No vasculitis was found in specimens with an inflammatory degree of 2, but in 57% with an inflammatory degree of 3 and in 100% with an inflammatory degree of 4. Vasculitis is only detectable in the mucous membrane changed by inflammation. Thus, the vasculitis in IBD is exclusively observed in the intestinal wall layers altered by inflammation. The extent of vasculitis depends on the degree of inflammation. An association between vasculitis and granuloma in Crohn's disease is seen in 5% of the cases.

Combination of p53 expression and p21 loss has an independent prognostic impact on sporadic colorectal cancer

There is no clear evidence on the prognostic and predictive value of abnormal p53 expression in colorectal cancer. The major downstream protein, p21, a cell cycle inhibitor, is transcriptionally regulated by p53. The prognostic impact of p21 expression in colorectal carcinomas is still under debate. In this study, we investigated the expression of p21 and p53 in a prospective cohort of 116 sporadic colorectal carcinomas at UICCII/III stage. We observed an expression of p21 in 26% and p53 in 63% of the carcinomas by immunohistochemistry. Patients with p21-negative colorectal carcinomas had a significant better recurrence-free and overall survival than patients with p21-positive carcinomas (p=0.02 and p=0.005). Expression of p53 was related to a better overall survival (p=0.048). The combination of p21-negative/p53-positive expression was significantly related to better recurrence-free and overall survival (p=0.007 and p=0.0001) and gained independent prognostic significance (HR: 3.4, p=0.01). Moreover, patients with combined p21-/p53+ expression had a remarkable benefit in overall survival after adjuvant chemotherapy as compared to the p21-/p53- subgroup (HR: 3.6, p=0.027). Our data suggest that the assessment of both p53 and p21 expression may provide prognostic information in colorectal cancer patients. This combination might be helpful to identify patients who could benefit from chemotherapy.

Effect of anastomosis level on continence performance and quality of life after colonic J-pouch reconstruction

Total mesorectal excision (TME) has become the recommended method for treatment of cancer in the middle or lower third of the rectum. Thus very low anastomoses are necessary to preserve continence, and pouch reconstruction is favored. It is unclear whether the level of anastomosis is important for continence and quality of life in colonic J-pouch reconstruction. In this investigation all patients were included who underwent curative elective anterior continuity resection with colorectal or coloanal J-pouch reconstruction for primary rectal cancer between January 2001 and December 2004. Exclusion criteria were distant metastases and any signs of recurrence at the time of investigation. Evaluation of continence performance by Wexner and Holschneider questionnaire and quality of life using the QLQ-C30 and QLQ-CR38 (EORTC) questionnaires was done 220 +/- 38 days after closure of the protective Ileostomy, which was performed 106 +/- 48 days after primary intervention. Fifty-two patients (79%) were analyzed. Colopouch rectal anastomosis was performed in eighteen cases and colopouch anal anastomosis in thirty-four cases. Fifty percent of the patients in both groups were continent for solid stool. Patients with a colopouch anal anastomosis had a significantly higher rate of incontinence for liquid stool, however. They took stool-regulating medicine more frequently and complained of fecal soiling and a restricted quality of life. Patients with a colopouch anal anastomosis had a significantly lower score on the most important points of the QLQ-C30 (emotional functioning, social functioning, pain, and quality of life). The same applied to the QLQ-CR38 for body image and problems with defecation. The quality of life of patients with a colopouch anal anastomosis was still considered acceptable compared with reference data for the normal healthy population, however. Both continence and quality of life are substantially affected by the level of the anastomosis after colonic pouch reconstruction. This suggests preservation of a small part of the rectum when oncologically feasible and performing a colopouch rectal anastomosis.

16-MDCT Angiography of Aortoiliac and Lower Extremity Arteries: Comparison with Digital Subtraction Angiography

OBJECTIVE

The objective of our study was to prospectively compare CT angiography (CTA) performed on a 16-MDCT scanner and digital subtraction angiography (DSA) in patients with peripheral arterial disease.

SUBJECTS AND METHODS

CTA and DSA were compared in 50 patients. CTA was independently evaluated by two blinded observers. DSA was evaluated by two additional blinded observers in consensus. Consensus DSA served as the reference standard for comparisons with CTA in terms of diagnostic quality, grading of stenoocclusive lesions, visualization of collaterals, impact on patient management, and time required for analysis.

RESULTS

No significant differences in diagnostic quality were observed between CTA and DSA above the ankle; both CTA observers noted significantly better visualization of pedal arteries (70 and 72 segments, respectively) than on DSA (57 segments). Of 958 stenoocclusive lesions on DSA, CTA observers 1 and 2 detected 933 and 929 lesions, respectively. Sensitivity and specificity for the detection of hemodynamically relevant (> 50%) lesions was 93.3% and 96.5% for observer 1 and 90.1% and 95.6% for observer 2. Collaterals were seen at 150 arterial levels on DSA compared with 97 and 92 levels on CTA (p < 0.05, both observers). Patient management decisions based on CTA were equivalent to those based on DSA in 49 of the 50 patients.

CONCLUSION

CTA is an effective noninvasive alternative to DSA for the evaluation of peripheral arterial disease.

Risk factors for clinical anastomotic leakage and postoperative mortality in elective surgery for rectal cancer

BACKGROUND AND AIMS

Clinical anastomotic leakage remains a major problem after anterior or low anterior resection for rectal cancer. The aim of this study was to assess the association between risk factors and anastomotic leakage and postoperative mortality.

MATERIALS AND METHODS

Two hundred seventy-six elective anterior or low anterior resections with anastomosis were performed and documented on-line from January 1995 to December 2004. Univariate and multivariate analyses with Bonferroni adjustment were carried out to identify relevant risk factors.

RESULTS

The rate of anastomotic leakage was 14.9% (41 of 276 patients) with a mortality of 12.2% (5 of 41 patients). Overall mortality was 2.5% (7 of 276 patients). Multiple regression analysis showed that smokers had an increased risk of anastomotic leakage [odds ratio (OR), 6.42; 95% confidence interval (CI), 2.68-15.36] as well as patients with coronary heart disease (OR, 7.79; 95% CI, 2.52-24.08). Smokers (OR, 13.20; 95% CI, 2.48-7.24) and patients with coronary heart disease (OR, 23.46; 95% CI, 4.33-27.04) also had an increased risk of postoperative mortality in the univariate analysis as well as patients with anastomotic leakage (OR, 16.25; 95% CI, 3.04-16.92).

CONCLUSIONS

Smoking and coronary heart disease are important risk factors for anastomotic leakage and postoperative mortality after elective resection for rectal cancer.

Ungewöhnlicher Fall einer akuten oberen gastrointestinalen Blutung: PEG-Implantationsmetastase eines Ösophaguskarzinoms - Fallbericht und Literaturübersicht

We present the case of a patient with an esophageal squamous cell carcinoma, who was treated primarily by radiotherapy. Due to dysphagia, the patient received a percutaneous endoscopic gastrostomy (PEG) without any sign of tumour at that time. Five months later the patient presented with an upper GI bleeding from a gastric ulcer, which histologically turned out to be a metastasis of the previously diagnosed squamous cell carcinoma. So-called "implantation metastases" at the percutaneous endoscopic gastrostomy site are rare and most of the cases have been described in patients with head and neck tumours. Moreover, the presentation as an upper GI bleed is very uncommon and needs the attention of both endoscopists as well as gastrointestinal oncologists. Clinicopathological features of this case with a brief review of the literature are presented.

Endothelin-1 receptor antagonist (LU-135252) improves the microcirculation and course of TNBS colitis in rats

The role of microcirculation in the pathogenesis and course of chronic inflammatory bowel disease is still unclear. The aim of this study was the evaluation of the role of microcirculation in colitis activity in the rat TNBS (trinitrobenzenesulfonic acid) colitis model using endothelin-1 and a selective endothelin-1 receptor antagonist (LU-135252). Target parameters were capillary blood flow, functional capillary density, vascular permeability, and leukocyte sticking as well as recording of hematocrit, weight course, diuresis, stool quality, and degree of inflammation using a histological colitis score. The acute phase of TNBS colitis is characterized by an extensive disturbance of microcirculation (a significant decrease in capillary blood flow and capillary density and a significant increase in capillary permeability and leukocyte sticking in the mucosa). There is also a significant increase in hematocrit and a significant decrease in diuresis and weight. An exogenous supply of endothelin-1 does not lead to an aggravation of these disorders because of a possible blockage of the endothelin-1 receptors by endogenous endothelin-1 in this florid inflammatory phase. Applying the selective endothelin-1 receptor A antagonist LU-135252 leads to a significant improvement of all microcirculatory parameters and clinical findings compared to the untreated colitis group. Direct improvement of capillary blood flow in the early phase of colitis leads to reduced colitis activity, which underscores the pathogenetic role of the microcirculation in the progression of colitis.

Ergebnisse der multiviszeralen Resektion des primären kolorektalen Karzinoms

BACKGROUND

In about 10 % of all patients with colorectal cancer, the primary invention already discloses adhesions or infiltration of adjacent organs. En bloc resection of the tumor-bearing bowel segment with adjacent organs is done to give patients a chance for curation, since intraoperative differentiation is not possible. The aim of this study is characterization of the patient population as well as evaluation of the morbidity and mortality associated with this type of extensive intervention.

METHOD

Between 1/95 and 6/04, we analyzed all patients with progressive primary colorectal cancer, who underwent multivisceral surgery with en bloc resection of at least one other organ. The target parameters were tumor characteristics as well as postoperative morbidity and mortality.

RESULTS

A total of 1 001 patients with colorectal cancer underwent surgery. 101 patients (10 %) required multivisceral resection. In 17 % the indication was exigent. About 70 % of the interventions involved the colon. Tumor perforation was seen in 17 % of patients with colon cancer and 16 % with rectal cancer. Resection of the inner genitals was most frequent in both colon and rectal cancer (26 and 84 %) followed by small bowel resection (21 %) and partial bladder resection (19 %). Other organs play a secondary role in rectal cancer while partial bladder resection (20 %) and abdominal wall resection (14 %) is observed more frequently in colon cancer. Resection of parenchymatous organs (kidney, suprarenal gland, spleen, pancreas, liver) and others like the stomach is quite rare in colon cancer. Actual tumor infiltration (T4 situation) was observed in 51 % of patients with colon cancer and in 64 % of those with rectal cancer. Local R0 resection (97 vs. 96 %) was successfully performed in nearly all colon and rectal cancer patients. The surgical major complication rate was 9 % in colon cancer and 19 % in rectal cancer. The mortality rate was 4 %.

CONCLUSION

Multivisceral en-bloc resection enables local R0 resection in the majority of cases with primary colorectal cancer. Despite sometimes extensive surgery, this type of procedure is associated with an acceptable morbidity and mortality. Since long-term survival is comparable to that in the T category (T3 or T4), multivisceral en-bloc resection is not only justified but also absolutely required in interventions with curative intention.

Selective COX-2 inhibition reduces leukocyte sticking and improves the microcirculation in TNBS colitis

The role of cyclooxygenase-2 inhibitors in the course of experimental colitis is controversially discussed. The aim of this study was to evaluate leukocyte-endothelium interaction and colitis activity after applying the selective cyclooxygenase-2 inhibitor NS-398 in a rat trinitrobenzene sulfonic acid (TNBS) colitis model. The acute phase of TNBS colitis is characterized by a significant reduction of capillary blood flow, capillary density, diuresis, and weight and a significant increase in capillary permeability, leukocyte sticking, and hematocrit. Applying the selective cyclooxygenase-2 inhibitor NS-398 leads to a significant improvement of all microcirculatory parameters and clinical findings compared to the (untreated) colitis group. There are no histopathological differences between the individual colitis groups. Acute colitis is characterized by an extensive disturbance of microcirculation together with signs of systemic inflammatory response syndrome. These alterations are significantly improved by inhibiting cyclooxygenase-2. The results support the described correlation between cyclooxygenase activation and leukocyte-endothelium interaction. Moreover, they underscore the postulated relation between leukocyte-endothelium interaction and capillary blood flow.

[Emergency management of thoracic trauma]

Thoracic injuries are a major cause of mortality during the "golden hour" of trauma. Many patients with chest trauma die after reaching the hospital. Less than 10% of all blunt thoracic injuries require a thoracotomy, and many potentially life-threatening conditions can be relieved by simple procedures, such as chest tube insertion.Thus, many cases of traumatic deaths due to chest injury may be prevented by prompt diagnosis and a standardized therapeutic approach in the emergency room. A high index of suspicion for lethal injury patterns, based on the mechanism of trauma and the clinical presentation, is a crucial prerequisite for an adequate initial assessment and management of patients with chest trauma. The worldwide implementation of standardized diagnostic and therapeutic guidelines, such as the "Advanced Trauma Life Support" (ATLS) protocol, has led to a significant reduction of early deaths attributed to thoracic injuries.

Becken-Bein-CT-Angiographie mit der 16-Zeilen-Multislice-Technik: Kontrastmittel-Enhancement und Bildqualität unter Einsatz eines standardisierten Untersuchungsprotokolls

PURPOSE

To assess the degree of enhancement and image quality of 16-slice multidetector CT angiography (MDCTA) of pelvic and lower limb arteries with a monophasic contrast medium injection protocol.

MATERIALS AND METHODS

Fifty patients underwent a CT angiography of the pelvic and lower limb arteries using the following parameters: collimation 16 x 1.5 mm, rotation time 0.5 s, table feed 40 mm/sec, slice thickness 2 mm, reconstruction interval 1.2 mm, 100 ml Iomeprol 400 + 60 ml normal saline, flow rate 4 ml/s, bolus tracking (threshold of 250 DeltaHU in aorta). Arterial enhancement was measured in all arterial segments. Maximum intensity projections (MIP) together with axial images were reviewed by two radiologists (consensus). If the results were inconclusive for stenosis, additional curved multiplanar reformations (MPR) were performed.

RESULTS

The mean arterial enhancement values were aorta: 314 +/- 69, pelvis: 342 +/- 105, thigh: 347 +/- 139, calf: 231 +/- 109 DeltaHU. The image quality was judged as excellent in 346 (77.6 %), adequate in 76 (17 %), and inadequate in 24 (5.4 %, all but one in calf and foot) of 446 arterial territories. An override of the contrast bolus below the knee occurred in 2 patients rendering the calf arteries nondiagnostic. Venous enhancement occurred in 13 patients but this compromised the diagnostic assessment in only one case. Additional MPRs were required accurately to assess stenoses in 22 of 200 arterial levels in 16 patients with marked arterial calcifications.

CONCLUSION

16-slice MDCTA with a monophasic contrast bolus of Iomeprol 400 provided good arterial enhancement and diagnostic image quality in 94.6 % of the depicted arterial segments. The majority (67 %) of nondiagnostic segments were below the ankle. MPRs were required in patients with marked calcification for accurate assessment of stenosis.

Gallbladder involvement of Henoch-Schönlein purpura mimicking acute acalculous cholecystitis

BACKGROUND/AIMS

We report the case of a 53-year-old man with fever and severe abdominal pain following an upper respiratory tract infection.

METHODS/RESULTS

The clinical signs, the laboratory markers, and the ultrasound findings were consistent with acute acalculous cholecystitis and he underwent cholecystectomy. Histologically the gallbladder showed vasculitis and the patient developed postoperatively a purpuric rash of the legs with transient ankle arthritis. Gastroscopy revealed prepyloric ulcers consistent with vasculitis. The patient was diagnosed as having Henoch-Schönlein purpura. Gastric ulcers as well as arthritis disappeared upon treatment with corticosteroids and proton pump inhibitors.

CONCLUSION

Taken together, Henoch-Schönlein purpura can mimic acute cholecystitis and should be considered as a rare differential diagnosis of acute cholecystitis.

Transluminale Bergung intravasaler Fremdk�rper

Patients with central venous lines or implanted Hickman catheters and port systems, suffer catheter embolization in 0.1-2.8% of the cases due to material fatigue or medical malpractice. In a 58-year-old vascular surgery patient, a central venous line catheter fragment was successfully retrieved from the pulmonary artery using a snare catheter via a transfemoral approach. From this case, we discuss the incidence, clinical aspects, diagnosis and interventional therapy of catheter embolization.

[Diagnostics and surgical therapy of enteric intussusception in adults illustrated by three cases]

The diagnosis of enteric intussusception is rare in adults but not in children. The clinical picture often takes an insidious course. Acute abdomen may also be caused by enteric intussusception. We report on three patients with enteric intussusception and acute abdomen. In two cases, a CT led to the diagnosis of invagination of the small intestine. In one patient, invagination of the terminal ileum was detected during coloscopy. All patients were submitted to limited segment resection and end-to-end anastomosis. In all three cases, the invagination was caused by benign pathological changes. Enteric intussusception in adults always requires surgery. In more than 95% of the cases, pathological findings are obtained intraoperatively, which are benign in the small intestine in 85-95% of the cases.

Tumour necrosis factor alpha and nuclear factor kappaB inhibit transcription of human TFF3 encoding a gastrointestinal healing peptide

BACKGROUND

and aims: Tumour necrosis factor alpha (TNF-alpha) induction of nuclear factor kappaB (NFkappaB) activation plays a major role in the pathogenesis of inflammatory bowel disease (IBD). Trefoil factor family peptides TFF1, TFF2, and TFF3 exert protective, curative, and tumour suppressive functions in the gastrointestinal tract. In this study, we investigated effects of the TNF-alpha/NFkappaB regulatory pathway by TNF-alpha on expression of TFFs.

METHODS

After TNF-alpha stimulation, expression of TFF genes was analysed by quantitative real time polymerase chain reaction and by reporter gene assays in the gastrointestinal tumour cell lines HT-29 and KATO III. Additionally, NFkappaB subunits and a constitutive repressive form of inhibitory factor kappaB (IkappaB) were transiently coexpressed. In vivo, morphological changes and expression of TFF3, mucins, and NFkappaB were monitored by immunohistochemistry in a rat model of 2,4,6-trinitrobenzene sulphonic acid induced colitis.

RESULTS

TNF-alpha stimulation evoked up to 10-fold reduction of TFF3 expression in the colon tumour cell line HT-29. Downregulation of reporter gene transcription of TFF3 was observed with both TNF-alpha and NFkappaB, and was reversible by IkappaB. In vivo, the increase in epithelial expression of NFkappaB coincided with reduced TFF3 expression during the acute phase of experimental colitis.

CONCLUSIONS

Downregulation of intestinal trefoil factor TFF3 is caused by repression of transcription through TNF-alpha and NFkappaB activation in vitro. In IBD, perpetual activation of NFkappaB activity may contribute to ulceration and decreased wound healing through reduced TFF3.

Persistent left superior vena cava: a reason for pseudodisplacement of a port catheter

Port catheters have been increasingly used in recent years. Using one case as an example, we demonstrate how an anatomic variation can easily become a pitfall when inserting a central venous catheter, port catheter, pacemaker or Swan-Ganz catheter. We report a case of persistent left superior vena cava, the most common variation in the thoracic venous system. Since these procedures are increasingly being performed, surgeons, anesthesiologists and radiologists should be aware of the possible anatomic variations.

Is reduced expression of mismatch repair genes MLH1 and MSH2 in patients with sporadic colorectal cancer related to their prognosis?

The majority of mutations in hereditary nonpolyposis colon carcinoma (HNPCC) patients affect the mismatch-repair genes (MMRG) MLHI and MSH2. In addition, mutations of these genes were found in about 15% of sporadic colorectal carcinomas which appear to be related to microsatellite instability (MSI). However, mutations in MMRG were not found in all MSI-positive carcinomas, but MMRG mutations may be relevant for the assessment of tumor characteristics and patients' prognosis. Therefore, we investigated the relationship between expression of MMRG, tumor biology and patients' survival. In 127 patients with sporadic colorectal carcinomas and a minimum of 5 years follow-up after curative surgery immunohistochemical detection of MLHI and MSH2 was analyzed semiquantitatively. Lost expression of MLHI has been found in tumor specimens from 10 patients, whereas MSH2 expression was missing in 5 patients. This reduced expression did not correlate with tumor stage, lymph node involvement, grading or tumor invasion into blood vessels. However, a significant correlation was found for lymphovascular invasion (P = 0.02) and localization within the colorectum (P = 0.003) in MLH1-negative carcinomas. In addition, although there was a clear tendency for longer overall survival (72 vs. 63 months) for patients with MLH1-negative carcinomas, significant differences for overall and recurrence-free survival were not seen. In conclusion of our results and a critical review of literature, the prognostic importance of the MMR genes in sporadic colorectal carcinomas remains controversial.

[Radical resection of colorectal carcinoma in the oldest old]

INTRODUCTION

The percentage of old people with colorectal cancer is steadily increasing in Western industrialized countries. Since there are only a few reports on the extent of surgery, it is unclear whether radical lymphadenectomy can also be safely performed as a standard operation in this age group.

METHODS

In a prospective study, we analyzed all patients who were > or = 80 years of age at the time of surgery and who were submitted to surgery between 1/95 and 12/00 due to a colorectal carcinoma. Target parameters were postoperative morbidity and mortality.

RESULTS

Fifty-seven of 665 patients (8.6%) were > or = 80 years of age. The median age was 85 years (range: 80-92). The gender ratio was 1:1.6 (G:E). Palliative surgery was performed in 19 of 57 patients. The remaining 38 patients underwent curative radical lymphadenectomy; 32 were elective and 6 emergency procedures. Mean ASA scores were 2.1 +/- 0.3 and 2.5 +/- 0.6. The following operations were performed: 13 right-sided and 15 left-sided hemicolectomies, 5 rectal resections, 3 rectal extirpations and 2 Hartmann's procedures. Two anastomotic insufficiencies (6%) had a complication-free course after revision. The rate of major surgical complications was 11%, that of internal complications 16%. Three patients (8%) died, one after an elective procedure and two after emergency laparotomy. One of the latter was an 89-year-old woman who refused to undergo a revision due to bleeding after Hartmann's procedure. Pneumonia and myocardial infarction were the cause of death in the other two patients.

CONCLUSION

Radical resection can be safely performed even at an advanced age. Since age-corrected survival is comparable to that of younger patients, surgery should be performed in the elderly under elective conditions according to oncological criteria.

Changes of colonic mucosal microcirculation and histology in two colitis models: an experimental study using intravital microscopy and a new histological scoring system

This study investigated capillary blood flow (CBF) and pathomorphological alterations in the mucosa of different bowel segments at different times after disease onset in rats with colitis induced by either trinitrobenzensulfonic acid (TNBS) or mitomycin-C. CBF was determined by intravital microscopy using fluorescein-labeled erythrocytes. The histological degree of inflammation was assessed by a new scoring system. Severe acute histological changes were found in the distal colon 24 hr after induction of TNBS colitis (score: 8.9+/-1.0). CBF was increased (2.9+/-0.05 vs. 2.6+/-0.04 nl/min in healthy controls). The histological alterations persisted until day 3 (8.5+/-0.9) when CBF significantly decreased (1.8+/-0.05 nl/min). After 15 days, moderate acute inflammation was still detectable histologically (5.4+/-1.3), but CBF had returned to normal values. In mitomycin-C colitis, changes developed mainly in the proximal colon: After three days, there was mild inflammation (2.8+/-1.2) with normal CBF (2.5+/-0.1 nl/min). After seven days, the inflammation had increased (4.8+/-1.1), while CBF had decreased (1.5+/-0.06 nl/min). These changes persisted for six weeks (5.3+/-0.7; 1.2+/-0.05 nl/min). These data suggest that disturbed colonic microcirculation may play an important role in the pathogenesis of inflammatory bowel disease regardless of the histopathomorphological alterations.

The insertion of the lesser and greater gastric omenta and its significance for the T classification of gastric carcinomas (UICC)

The problem of T classification of proximal gastric carcinomas is becoming increasingly important due to a rise in the incidence of these tumors. The aim of this study was to examine the gastric insertion of the lesser and greater omenta and its role in the T classification of gastric carcinomas. The stomach and greater and lesser omenta were removed from 76 fixed cadavers and 12 measurements each were done in defined localizations. The lesser omentum extended to the gastric wall in 98% of the cases. This junction as well as the omental thickness and thus the retroperitoneal part are especially pronounced in the cardiac region. According to the current UICC classification, even advanced tumors extending into the gastric wall can be classified T2 as long as they do not penetrate the visceral peritoneum. This results in "understaging" and a seemingly poorer prognosis for cardiac carcinomas. Our study results support the recommendation of Hermanek and Wittekind [5] to subdivide the T2 stage of gastric carcinomas on the basis of infiltration depth.

The prognostic significance of tumor vascularization in patients with localized colorectal cancer

Angiogenesis is essential for tumor growth and metastasis, and vascular density is known as an independent prognostic factor in several tumor entities. We studied the prognostic relevance of vascular density in colorectal cancer, examining 146 patients treated surgically for cure. Tumor sections were immunostained with JC70, an endothelial cell marker. Microvessel quantification used light microscopy. The slides were scanned at a low magnification, and individual microvessel counts were made on a x200 field in the area of the most dense neovascularization. Vascular density was found to be 75+/-27/visual field and to be independent of age, sex, pT and pN categories, tumor recurrence, and overall survival. Overall survival in the subgroup of patients with tumor recurrence was significantly shorter with tumors of greater vessel density (>75) than in those of less vessel density (<75). Multivariate analysis showed microvessel count to be an independent prognostic factor for the overall survival rate of patients with tumor recurrence; among these patients there was also a significant difference in the relapse-free survival rates between the hypovascular and the hypervascular groups. Our findings suggest that the microvessel density of the primary tumor determines the speed of tumor recurrence after metastatic disease has been triggered by other, unknown mechanisms. Although tumor vascularization can be linked to the aggressiveness of colorectal cancer, it has no value as a new prognostic marker in clinical practice.

Dietary resistant starch and chronic inflammatory bowel diseases

These studies were performed to test the benefit of resistant starch on ulcerative colitis via prebiotic and butyrate effects. Butyrate, propionate, and acetate are produced in the colon of mammals as a result of microbial fermentation of resistant starch and other dietary fibers. Butyrate plays an important role in the colonic mucosal growth and epithelial proliferation. A reduction in the colonic butyrate level induces chronic mucosal atrophy. Short-chain fatty acid enemas increase mucosal generation, crypt length, and DNA content of the colonocytes. They also ameliorate symptoms of ulcerative colitis in human patients and rats injected with trinitrobenzene sulfonic acid (TNBS). Butyrate, and also to a lesser degree propionate, are substrates for the aerobic energy metabolism, and trophic factors of the colonocytes. Adverse butyrate effects occur in normal and neoplastic colonic cells. In normal cells, butyrate induces proliferation at the crypt base, while inhibiting proliferation at the crypt surface. In neoplastic cells, butyrate inhibits DNA synthesis and arrests cell growth in the G1 phase of the cell cycle. The improvement of the TNBS-induced colonic inflammation occurred earlier in the resistant starch (RS)-fed rats than in the RS-free group. This benefit coincided with activation of colonic epithelial cell proliferation and the subsequent restoration of apoptosis. The noncollagenous basement membrane protein laminin was regenerated initially in the RS-fed group, demonstrating what could be a considered lower damage to the intestinal barrier function. The calculation of intestinal short-chain fatty acid absorption confirmed this conclusion. The uptake of short-chain fatty acids in the colon is strongly inhibited in the RS-free group, but only slightly reduced in the animals fed with RS. Additionally, RS enhanced the growth of intestinal bacteria assumed to promote health. Further studies involving patients suffering from ulcerative colitis are necessary to determine the importance of RS in the therapy of a number of intestinal diseases and the maintenance of health.

Does glutamine reduce bacterial translocation? A study in two animal models with impaired gut barrier

Failure of intestinal barrier function and subsequent translocation of bacteria from the gut are believed to play a decisive role in the development of systemic septic complications, for example, following major trauma or major abdominal surgery. This study evaluated: (a) the effect of glutamine on colonic microcirculation and electrophysiological parameters reflecting gut barrier function, (b) the translocation of live bacteria to extraintestinal organs, and (c) disease outcome in two animal models with impaired gut barrier function. Severe acute pancreatitis or colitis was induced in rats randomized for therapy with or without glutamine (0.5 g/kg daily). After 48 h one animal group was prepared for intravital microscopy of colonic capillary blood flow and electrophysiological measurement of gut permeability; another was killed after 96 h for histological and microbiological examination. In animals with pancreatitis, glutamine (Gln) supplementation significantly improved gut permeability, i.e., Gln increased colonic transmucosal resistance from 67+/-7 to 92+/-3 Omega/cm(2) and decreased mannitol flux through the epithelium by 53%. Capillary blood flow in the colonic mucosa was improved by 25%. The prevalence of pancreatic infections was reduced from 86% in animals on standard parenteral nutrition to 33% in animals given the Gln-enriched diet (P<0.05); mortality decreased by 32%. In colitis, Gln had no significant effect on these parameters except for improving colonic capillary blood flow in colon segments not adjacent to the major injury site. Glutamine supplementation improves colonic capillary blood flow, stabilizes gut permeability, and reduces secondary pancreatic infections and mortality in severe rodent pancreatitis, but it is not helpful in colitis. This confirms previous reports that glutamine stabilizes gut barrier function only in certain diseases. Our experimental data strongly suggest that acute pancreatitis (rather than colitis) is one of the diseases with gut barrier dysfunction in which glutamine substitution may be helpful to reduce bacterial translocation and should therefore be tested in a controlled clinical trial.

[Rectal resection within the scope of multi-visceral interdisciplinary resection in the pelvis]

Multivisceral resectioning is the only curative treatment for progressive carcinomas extending beyond the organ. The results of 25 consecutively operated patients are presented in this prospective observational study. Twelve patients underwent surgery for a primary tumor and 13 for a recurrence. Radical resectioning was achieved in 5 of 12 and in 3 of 13 patients. Restoration of continuity obtained in 11 of 12 and in 7 of 13 patients. Morbidity was 33% and 62%. None of the patients died from complications. An aggressive surgical approach is justifiable on account of the acceptable morbidity and mortality as well as the high rate of preserved continence through modern reconstruction procedures.

Does microcirculation play a role in the pathogenesis of inflammatory bowel diseases? Answers from intravital microscopic studies in animal models

The potential role of intestinal microcirculation for the development of inflammatory bowel diseases (IBD) has not been systematically investigated, mainly because of methodological problems. Using a well-established rodent model of IBD and intravital microscopy, the present study investigated whether (and when) gut microcirculation is disturbed in IBD, and whether microcirculatory disorders contribute to histological and functional alterations in the development of IBD. Colitis was induced by rectal injection of trinitrobenzene sulfonic acid. After 1, 3, and 15 days rats were laparotomized for intravital microscopic determination of mucosal colonic blood flow. In a second series it was examined whether enhancing colonic capillary blood flow by hemodilution therapy stabilizes colonic wall resistance and other electrophysiological parameters of gut permeability. Additional measurements involved hemodynamic monitoring and histological examinations. Colonic capillary blood flow was significantly decreased 3 days after colitis induction (1.8 +/- 0.05 vs. 2.6 +/- 0.04 nl/min in healthy control animals) when histology revealed signs of acute inflammation, and normal values after 15 days (2.4 +/- 0.06 nl/min) when chronic histological changes were evident. Hemodilution therapy enhanced colonic capillary blood flow in the initial stage (2.1 +/- 0.02 vs. 1.6 +/- 0.02 nl/min in saline-treated animals with trinitrobenzene sulfonic acid colitis) and improved gut resistance and electronic chloride secretion (73 +/- 15 vs. 33 +/- 8 microA cm2). Histological alterations were not significantly attenuated. Impaired colonic capillary blood flow in the initial stage of experimental colitis and improved mucosal microcirculation with stabilized gut permeability suggests that the early microcirculatory disturbances precede chronic histological changes and influence functional alterations in the course of the disease. Research should be continued in this field because important mechanisms in the pathogenesis of IBD and potentially therapeutic (vasoactive) substances may otherwise be overlooked.

Radical resection in obstructing colorectal carcinomas

Emergency resections of obstructing colorectal carcinomas usually involve only limited rather than radical lymphadenectomy, which may contribute to the poor long-term survival of these patients. Thirty patients with ileus due to colorectal cancer have been included in a prospective follow-up study since January 1995. Seventeen of these underwent potentially curative resections with radical locoregional lymphadenectomy according to current standards of elective oncological surgery; 2 had radical right and 15 had radical left hemicolectomies. Postoperative morbidity was 18%. An 89-year-old patient died following postoperative bleeding from the colostomy site. During the same period, 13 patients with a metastasizing colorectal carcinoma underwent palliative emergency surgery with a resection rate of only 38%. Morbidity and mortality were 69% and 46%, respectively. These results suggest that emergency radical resections can be safely performed in the majority of patients with obstructing colorectal cancer without increasing the complication rate.

[Protective effect of glutamine on microcirculation of the intestine in experimental colitis]

Parenteral glutamine application can stabilize intestinal permeability and mucosal integrity. It is not known whether glutamine influences the microcirculation in the large intestine. This study thus employs intravital microscopy to investigate mucosal microcirculation in the ascending and descending Colon of Sprague-Dawley rats with TNBS colitis. The animals were randomized and treated with either saline solution (placebo) or glutamine (verum). In the severely inflamed descending colon, TNBS colitis involves a significant capillary blood flow reduction that is not improved by glutamine application. Though the ascending colon shows only a mild inflammatory reaction, its microcirculation is likewise significantly reduced. Here glutamine therapy is associated with an increase in capillary blood flow, indicating that it has a protective effect on the microcirculation of the secondarily involved intestinal segment.

[Lack of effect of EGF on epithelial barrier function in experimental TNBS colitis]

This study tested the hypothesis that EGF has a protective effect on the intestinal barrier function in experimental TNBS-induced colitis. EGF was given intraperitoneally one hour before and 24 hours after induction of colitis. The rats were killed 48 hours after induction of colitis: The distal colon was resected and mounted into Ussing chambers. Flux measurements were performed for Na+ and mannitol, and epithelial and subepithelial resistances were determined. A semiquantitative histological score was used to grade acute and chronic inflammation. Compared to controls, TNBS caused a 3-fold increase in both fluxy, indicating enhanced paracellular permeability. There rates was a severe reduction of total and epithelial resistances indicating a dramatic defect of epithelial barrier function. EGF failed to improve the electrophysiologic and histologic parameters. Therefore, EFG has no protective effective in experimental TNBS colitis.