To eat or not to eat? Effect of fasting prior to abdominal sonography examinations on the quality of imaging under routine conditions: A randomized, examiner-blinded trial.

OBJECTIVE: Although often recommended, it is unclear whether fasting enhances the imaging quality of abdominal sonography examinations. The aim of this study was to produce experimental evidence of the effect of fasting on the imaging quality of abdominal organs. MATERIAL AND METHODS: Formally consenting medical inpatients who underwent elective abdominal sonography examinations at a university medical center were randomized to either a fasting or a non-fasting preparation. Blinded examiners evaluated the imaging quality of 11 anatomical regions. The primary end-point was the proportion of completely evaluable patients for each region. In secondary analyses, values of an imaging index reflecting the mean imaging quality of all regions (range 0-1) were compared. RESULTS. Of 280 screened patients, 102 (36%) met the exclusion criteria and 35 (13%) declined participation. Of the 143 randomized patients, 130 (91%) were included in the primary analyses (66 fasting, 64 non-fasting). The proportion of completely evaluable patients did not differ significantly for any of the 11 regions, but a large nominal difference occurred for the gallbladder (45/66 (73%) fasting versus 34/64 (56%) non-fasting patients, p=0.051). The median (range) imaging index was 0.57 (0.14-0.95) for fasting and 0.43 (0.00-1.00) for non-fasting subjects (p =0.078). A significant (p=0.002) difference favoring fasting was detected in the post-hoc subgroup analyses for male patients. CONCLUSIONS: For examinations of the gallbladder and for male patients, fasting might improve the sonographic imaging quality to some extent. Overall, no significant improvement in the imaging quality of abdominal organs was reached with a fasting preparation.

[Female patient with unclear liver lesions after breast cancer. Imaging modalities as a key to diagnosis]. / Patientin mit unklaren Leberraumforderungen nach Mammakarzinom. Die Bildgebung als Schlüssel zur Diagnose.

The case of a 58-year-old female patient with well-differentiated breast cancer (T1 stadium) without axillar lymphadenopathy and with multiple suspect liver lesions is described. Liver metastases of the breast cancer could be excluded histologically, however, serologic testing for echinococcosis was negative. After contrast-enhanced sonography and because of the complex B-mode appearance of the liver lesions, cystic echinococcosis was suspected. This could be verified histologically after hemihepatectomy.

Unnecessary delay of diagnosis of buried bumper syndrome resulting in surgery.

Percutaneous endoscopic catheter gastrostomy (PEG) is a convenient way to supply enteral nutrition for patients with swallowing disorders. One rare complication of PEG is the buried bumper syndrome where gastric mucosa overgrows the internal bumper and prevents free flow of the feeding solution. As a consequence, the application of enteral feeding has to be stopped until a free outflow is re-established. We report a case of buried bumper where symptoms were misinterpreted for several months as PEG stoma infection by the homecare service. This led to a vastly delayed diagnosis and treatment. As endoscopic intervention was unsuccessful, surgical PEG removal was required. In consequence, we recommend early endoscopic exploration in cases with prolonged inflammatory signs at the PEG stoma site in order to avoid misdiagnosis of buried bumper syndrome and to allow timely endoscopic intervention.

Doppler ultrasound and intravenous contrast agents in gastrointestinal tract disorders: current role and future implications.

Doppler sonography is part of the entire sonographic evaluation of intestinal diseases. It can help in estimating disease activity, although as the sole method to assess the patients situation it is not acceptable. New methods to quantify disease activity, such as contrast enhanced sonography, are at an experimental level and have to be evaluated in more detail.

Intracellular localization is a cofactor for the phototoxicity of protoporphyrin IX in the gastrointestinal tract: in vitro study.

Photodynamic therapy (PDT) is a new treatment modality for solid tumors as well as for flat lesions of the gastrointestinal tract. Although the use of 5-aminolevulinic acid-induced protoporphyrin IX (PPIX) shows important advantages over other photosensitizers, the main mechanisms of phototoxicity induced are still poorly understood. Three human colon carcinoma cell lines with variable degrees of differentiation and a normal colon fibroblast cell line were used to generate a suitable in vitro model for investigation of photosensitizer concentration as well as the applied light dose. Also, the effects of intracellular photosensitizer localization on efficiency of PDT were examined, and cellular parameters after PDT (morphology, mitochondrial transmembrane potential, membrane integrity and DNA fragmentation) were analyzed to distinguish between PDT-induced apoptosis from necrosis. The fibroblast cell line was less affected by phototoxicity than the tumor cells to a variable degree. Well-differentiated tumor cells showed higher toxicity than less-differentiated cells. After irradiation, cell lines with cytosolic or mitochondrial PPIX localization indicate a loss of mitochondrial transmembrane potential resulting in growth arrest, whereas membrane-bound PPIX induces a loss of membrane integrity and consequent necrosis. Although the absolute amount of intracellular photosensitizer concentration plays the main determining role for PDT efficiency, data indicate that intracellular localization has additional effects on the mode of cell damage.

Gallbladder motility in healthy volunteers: effects of age, gender, body mass index, and hair color.

BACKGROUND/AIMS: Ultrasonographic determination of gallbladder motility is sparsely performed in clinical practice as the examination is considered to be time consuming and there is uncertainty about a number of parameters possibly influencing the results. The aims of this study were a) to establish normal values for a simple ultrasonographic test and b) to evaluate the influence of different parameters on gallbladder motility. METHODOLOGY: In 62 systematically age- and sex-matched healthy volunteers, ultrasonographic measurements of gallbladder volume (ellipsoid method, planimetry and sum-of-cylinders method) were performed fasting and 5, 10, 20, 30, 40, 50, 60, 70 and up to 75 min after stimulation with a standardized high-caloric liquid meal. RESULTS: Using the ellipsoid method, gallbladder fasting volume (V0) reached a mean value (+/- SD) of 24.6 +/- 10.0 mL with an ejection fraction of 65.9 +/- 19.1%. Age, gender and hair color did not influence parameters of gallbladder contraction. Body mass index showed a weak correlation with V0 but not with ejection fraction. There was a highly significant correlation between the ellipsoid method and longitudinal planimetry and the sum-of-cylinders method, respectively. CONCLUSIONS: Ultrasonographic measurement of gallbladder motility in healthy volunteers shows a very wide scattering of normal values. In the interpretation of gallbladder emptying, age, gender and body mass index do not have to be considered. Determination of gallbladder motility may be performed by a rather simple approach with oral stimulation and ellipsoid method or longitudinal planimetry as easily applicable ultrasonographic measurements.

[Detection of lymph node metastases of malignant melanoma by palpation and ultrasound]. / Palpatorische und sonographische Detektion von Lymphknotenmetastasen bei lokal fortgeschrittenem malignen Melanom.

BACKGROUND AND PURPOSE: Early detection of metastases of malignant melanoma has therapeutic implications. The aim of this study was to evaluate palpation and ultrasound examination in the diagnostics of lymph node metastases in locally advanced melanoma. PATIENTS AND METHODS: 83 patients suffering from melanoma (Clark level IV or V) were examined for lymph node metastases by palpation and sonography. Findings were compared to histopathologic results after lymph node extirpation if available or the findings at the next follow-up visit. RESULTS: Lymph node metastases were confirmed histopathologically in 14 patients at the first study visit, in three others at the control visit. Sensitivity, specificity, positive and negative predictive values of palpation for the detection of metastases or suspicious nodes with increasing volume at follow-up in this population were 65%, 81%, 48%, and 89%, and of ultrasound 100%, 66%, 45%, and 100%, respectively. CONCLUSION: Sonography of lymph nodes should be included as a standard procedure in the detection of metastases of locally advanced malignant melanoma.

Technology insight: advances in liver imaging.

The role of diagnostic imaging in the assessment of liver disease continues to gain in importance. The classic techniques used for liver imaging are ultrasonography, CT and MRI. In the past decade, there have been significant advances in all three techniques. In this article, we discuss the advances in ultrasonography, CT and MRI that have improved assessment of focal and diffuse liver disease, including the development of hardware, software, processing algorithms and procedural innovations.

Improvement in the routine diagnostic assessment of the liver by high-resolution sonography: an analysis of 999 cases.

OBJECTIVE: High-frequency ultrasound transducers have been helpful in certain settings of transabdominal ultrasound examination, and their role in the evaluation of the liver surface in patients with cirrhosis is well documented. However, their value in the routine assessment of the liver has not yet been analysed systematically. The aim of this pilot study was to clarify whether the additional use of high-frequency ultrasound as compared to the standard 3.5 MHz-transducer is of any benefit. MATERIAL AND METHODS: A total of 999 patients from a tertiary care medical centre were examined with a wideband 3.5 MHz- and a high-frequency transducer (band width 4.5 to 10 MHz) with tissue harmonic imaging using one of two high-end ultrasound machines (Siemens Sonoline Elegra or Hitachi EUB-8500). Findings on hepatic pathologies were collected on a standardized documentation sheet and were evaluated using descriptive statistics. RESULTS: In all, 948 patients showed a plain liver surface when the 3.5 MHz transducer was used, whereas this was only true for 862 patients examined with the high-frequency probe. Using the 7.5 MHz probe, the structure of the liver parenchyma appeared to be homogeneous (n=800; 80.1%) less often than when the 3.5 MHz probe (n=822; 82.3%) was used. More cases of liver cirrhosis were suspected with the high-frequency probe (n=66; 6.6% as compared with n=49; 4.9%). In 85 patients (8.5%) new hepatic pathologies were described which had not been detected with the 3.5 MHz probe. The examiners judged the high-frequency examination to be helpful in 284 cases. The time needed for the additional examination ranged between 0.5 and 10 min (mean: 2.2 min). CONCLUSIONS: This study demonstrates that the additional use of a high-frequency transducer during routine abdominal examinations reveals new hepatic pathologies in a significant proportion of examined patients, without substantial prolongation of the overall examination period.

Bile salt-induced apoptosis in human colon cancer cell lines involves the mitochondrial transmembrane potential but not the CD95 (Fas/Apo-1) receptor.

BACKGROUND AND AIMS: Depending on their physico-chemical characteristics, bile acids can be potent inducers of apoptosis in colon cancer cells. This observation contrasts with bile acids being promoters of colorectal cancer carcinogenesis. Our recent observation of caspase activation in deoxycholate (DC)-treated colon cancer cell lines prompted us to analyze the mechanisms of bile acid-induced colon cancer cell death. METHODS: CD95 expression was correlated to DC-induced cell death in four colon cancer cell lines. Mitochondrial transmembrane potential (MTP) was determined in whole cells as well as in isolated mitochondria. RESULTS: On 2 of the 4 human colon cancer cell lines investigated, no CD95 was detected. These data were supported by a lack of CD95 mRNA in those cell lines that did not express CD95 on their surface. The apoptotic response to bile acids did not correlate with CD95 receptor expression on the respective cell lines. Therefore, we analyzed the MTP after the addition of toxic bile acids. MTP was destabilized early after the addition of deoxycholate to SW480 cells. These data were confirmed in isolated mitochondria, which showed strong swelling after the addition of DC. Accordingly, release of cytochrome-c from the mitochondrial intermembrane space into the cytosol, indicating dissipation of the MTP, and subsequent caspase-3 cleavage were detectable as early as 3 min after the addition of DC. CONCLUSION: In contrast to hepatocytes and hepatic carcinoma cell lines, DC induces apoptosis in colon cancer cell lines via a CD95 receptor-independent mechanism. Direct induction of the mitochondrial permeability transition by toxic bile acids is suggested as the apoptosis-inducing mechanism in colon cancer cells.

Thioredoxin reductase 1 expression in colon cancer: discrepancy between in vitro and in vivo findings.

Thioredoxin and thioredoxin reductase 1 (TR1) are redox proteins that have been implicated in cellular events such as proliferation, transformation, and apoptosis. Analysis of the expression and localization of TR1 in different normal and cancer cell lines and in colon tissues (normal, neoplastic, or inflamed) was performed using reverse transcription-PCR and in situ hybridization. TR1 mRNA was expressed in all analyzed tissues with TR mRNA-positive cells restricted to the stroma of colon crypts, partly being CD3 or CD56 positive. In neoplastic areas of colonic cancer tissue, a loss of TR was obvious. None of the epithelial cells in colonic mucosa expressed TR mRNA, whereas more than 70% of HT-29 cells grown in monolayer were positive for TR. In contrast, HT-29 cells, grown as spheroids or as tumors in SCID mice, were negative for TR. In contrast to these in vitro findings and previous studies, there is no evidence that TR plays a significant role in vivo in normal cell growth in colonic epithelial cells. The mechanism underlying the loss of TR1-positive/CD3-positive/CD56-positive cells or the biologic consequence of this phenomenon observed in neoplastic colonic tissue remains to be clarified.

Bile acids mimic oxidative stress induced upregulation of thioredoxin reductase in colon cancer cell lines.

Bile acids have been suggested to play an important role in the etiology of colon and gastric cancer after gastrectomy, but the molecular biology of these effects is poorly understood. We evaluated the effect of different bile acids on human gastric and colon carcinoma cells and identified genes by RNA arbitrarily primed PCR for differential display that are modulated following treatment with hydrophobic bile acids. Thioredoxin reductase (TR) mRNA was upregulated after treatment with taurochenodeoxycholic acid (TCDCA) in St 23132 cells. This raised the question whether deoxycholic acid (DCA) would have regulative effects on TR in HT-29 cells. After an incubation time of 6 h with DCA, TR mRNA expression was increased up to threefold. Ursodeoxycholic acid had no influence on TR mRNA expression. The upregulation of TR after DCA incubation was almost identical to incubation with 12-O-tetradecanoylphorbol-13-acetate. This implies that hydrophobic bile acids mediate oxidative stress in gastrointestinal cancer cells, which was confirmed by measurement of oxidative burst after treatment with DCA. The results suggest that hydrophobic bile acids induce oxidative stress in gastrointestinal cancer resulting in a compensatory upregulation of TR mRNA, one of the key components in the complex anti-oxidant defense system within eukaryotic cells. The activation of at least parts of the redox signaling system is potentially related to the cytotoxicity and the stimulation of the cell death machinery induced by toxic bile acids.

Functional expression of the interleukin-11 receptor alpha-chain and evidence of antiapoptotic effects in human colonic epithelial cells.

A tissue-protective effect of interleukin-11 (IL-11) for the intestinal mucosa has been postulated from animal models of inflammatory bowel disease (IBD). Despite the fact that the clinical usefulness of the anti-inflammatory effects of this cytokine is presently investigated in patients with IBD, there are no data available regarding the target cells of IL-11 action and the mechanisms of tissue protection within the human colonic mucosa. IL-11 responsiveness is restricted to cells that express the interleukin-11 receptor alpha-chain (IL-11Ralpha) and an additional signal-transducing subunit (gp130). In this study, we identified the target cells for IL-11 within the human colon with a new IL-11Ralpha monoclonal antibody and investigated the functional expression of the receptor and downstream effects of IL-11-induced signaling. Immunohistochemistry revealed expression of the IL-11Ralpha selectively on colonic epithelial cells. HT-29 and colonic epithelial cells (CEC) constitutively expressed IL-11Ralpha mRNA and protein. Co-expression of the signal-transducing subunit gp130 was also demonstrated. IL-11 induced signaling through triggering activation of the Jak-STAT pathway without inducing anti-inflammatory or proliferative effects in colonic epithelial cells. However, IL-11 stimulation resulted in a dose-dependent tyrosine phosphorylation of Akt, a decreased activation of caspase-9, and a reduced induction of apoptosis in cultured CEC. In HLA-B27 transgenic rats treated with IL-11, a reduction of apoptotic cell numbers was found. This study demonstrates functional expression of the IL-11Ralpha restricted on CEC within the human colonic mucosa. IL-11 induced signaling through triggering activation of the Jak-STAT pathway, without inducing anti-inflammatory or proliferative effects. The beneficial effects of IL-11 therapy are likely to be mediated by CEC via activation of the Akt-survival pathway, mediating antiapoptotic effects to support mucosal integrity.