[A 59-year-old woman with upper abdominal pain and fever]

A 59-year-old woman suffered from fever and upper abdominal pain. The computed tomography (CT) scan revealed a liver lesion. Conventional imaging techniques (CT, magnetic resonance imaging, contrast-enhanced ultrasonography) did not allow for a consistent diagnosis. Fine needle biopsy of the liver lesion was performed. Histologically, fibrotic inflammation was found and an inflammatory pseudotumor (IPT) diagnosed. Despite treatment with steroids and antibiotics, the size of the IPT increased; thus, surgical resection was necessary. In case of fever of unknown origin, IPT should be considered as a potential diagnosis.

[Diagnosis of and therapy for hepatocellular carcinoma]

The interdisciplinary guidelines at the S3 level on the diagnosis of and therapy for hepatocellular carcinoma (HCC) constitute an evidence- and consensus-based instrument that is aimed at improving the diagnosis of and therapy for HCC since these are very challenging tasks. The purpose of the guidelines is to offer the patient (with suspected or confirmed HCC) adequate, scientifically based and up-to-date procedures in diagnosis, therapy and rehabilitation. This holds not only for locally limited or focally advanced disease but also for the existence of recurrences or distant metastases. Besides making a contribution to an appropriate health-care service, the guidelines should also provide the foundation for an individually adapted, high-quality therapy. The explanatory background texts should also enable non-specialist but responsible colleagues to give sound advice to their patients concerning specialist procedures, side effects and results. In the medium and long-term this should reduce the morbidity and mortality of patients with HCC and improve their quality of life.

Toxicity of ingested cadmium to the nematode Caenorhabditis elegans

Benthic organisms ingest dissolved and particle-bound contaminants together with their food, whereas it is not clear which fraction of the ingested suspension causes the toxic effects. In the standard toxicity test using the nematode Caenorhabditis elegans, the organisms are fed with bacteria that bind contaminants, thus influencing the bioavailability of the contaminants for the organisms. To unravel the role of food bacteria in the toxicity of contaminants in C. elegans, suspensions with varying densities of bacteria were spiked with the toxic metal cadmium (Cd), either via the water or via the bacteria. The toxicity of Cd to C. elegans was clearly related to the uptake of bacteria in the nematode's gut. An increase in the bacterial density resulted in a significant decrease in the toxicity of Cd such that toxic effects better correlated with the aqueous than with the bacterial-bound or total Cd concentrations. The results suggested that the aqueous Cd that was ingested together with the food was the best available fraction and thereby mainly caused the observed toxicity on the reproduction of C. elegans.

Clinical signs in the diagnosis of deep vein thrombosis

AIM

Deep vein thrombosis (DVT) is an insidious disease wherein more than 15 different clinical signs are described. The aim of this work was to focus on these clinical signs and to test them for their importance in making a diagnosis of DVT.

METHODS

All patients treated with a tentative diagnosis of DVT in the emergency department were asked to take part in the study. Out of the 254 patients who were examined in order to exclude DVT, 204 patients agreed to participate in the study. The patients who agreed to take part were tested for fifteen clinical examination signs. The Wells score was then determined.

RESULTS

Sixty-two were diagnosed with DVT. For 142 patients, DVT could be ruled out. The probability of DVT for 9 signs together is 88%, and for 3 signs is 78%. The negative predictive values are 91-95%. The combination of the clinical signs showed a specificity of 100%, independent if the patients were old, comorbid, and were diagnosed with the thrombosis in the lower limbs. The determination of the Wells score resulted in no convincing evidence for or against the diagnosis of DVT.

CONCLUSION

We suggest a modified Wells score integrating missing clinical signs with more reliable predictive values. Even with the availability of ultrasound, clinical signs have not become superfluous. They are quick to carry out, safe, cheap and an important addition to the Wells score, particularly for multimorbid and elderly patients.

[Localisation of hepatic lesions to liver segments according to sonography (US), computed tomography (CT) and surgery (OP): a comparative study]

INTRODUCTION

The localisation of focal liver lesions is usually performed according to the Couinaud classification system. The exact description of localisation and size of liver lesions is especially important for surgical procedures. The aim of this prospective study was the evaluation of differences and agreements in the localisation and size of hepatic lesions as found by ultrasound (US), computed tomography (CT) and according to the intraoperative status (OP).

MATERIAL AND METHODS

32 patients (21 male, 11 female) were enrolled in the study. The results obtained from sonography, computed tomography and surgery were classified into 5 categories for localisation and for size, respectively.

RESULTS

According to the agreement between sonography and computed tomography, 25 % of all hepatic lesions were classified into category 1 (exact agreement), whereas 40.6 % were ranked into category 2 (almost exact agreement). Correlating sonography and intraoperative results, 31.3 % of the lesions were classified into category 1 and 46.9 % into category 2. In the comparison of CT with OP, 34.4 % of the lesions were found to be in category 1 and 43.8 % in category 2. Concerning the size of the lesions, almost half of the tumours (46.9 %) were classified into category 1 on the basis of the correlation between US and CT and 21.9 % on the basis of the correlation between US and OP.

DISCUSSION

The localisation and description of the size of hepatic lesions is mainly similar or even identical on the basis of the different methods. Further improvements might be achieved by the introduction of a consistent nomenclature.

Irinotecan plus gemcitabine and 5-fluorouracil in advanced pancreatic cancer: a phase II study

AIMS

The aim of the present study was to evaluate the 6-month survival rate of patients with inoperable or metastatic pancreatic cancer treated with irinotecan and gemcitabine plus 5-fluorouracil. Secondary efficacy end points included response rate, time to progression (TTP), overall survival (OS) and toxicity.

PATIENTS AND METHODS

30 patients with histologically proven pancreatic carcinoma and at least one bidimensionally measurable lesion were enrolled. Of the patients, 83% had metastatic and 17% locally advanced disease. One cycle, lasting 21 days, comprised treatment on days 1 and 8 consisting of 75 mg/m(2) irinotecan i.v. for 90 min, 1,000 mg/m(2) gemcitabine i.v. for 30 min and 2,000 mg/m(2) fluorouracil (5-FU) for 24 h. A total of six cycles was planned for each patient.

RESULTS

28 patients competed at least one treatment cycle and were therefore assessable for efficacy, and 75% of them achieved the primary end point of the study (survival after 6 months). One-year survival was 25%. Stabilization (partial response and stable disease) was observed in 35.7% (10/28) and partial remission in 7.1% (2/28). The objective response rate was 7.1% (2/28) after completion of the six cycles. Median TTP was 3.4 months (1.2-11.5), and median OS was 8.3 months (2.1-36.2). Regarding severe hematological toxicities, only neutropenia was observed (grade 3 20.7%, 6/29, and grade 4 3.5%, 1/29). In spite of anti-emetic supportive care, nausea affected most of the patients: 79.3% (23/29). Grade 3 vomiting was observed in 4 of the 29 patients (13.8%) and grade 4 in 1 patient (3.5%). Only 1 patient experienced diarrhea grade 3 (3.5%) and 1 patient (3.5%) suffered from a grade 3 peroneal nerve enervation.

CONCLUSIONS

A combination of irinotecan, gemcitabine and 5-FU is feasible and shows considerable efficacy in patients with inoperable or metastatic pancreatic cancer. Due to its low toxicity, this combination might be an interesting cytotoxic regimen in addition to targeted therapies.

Comparison of low and high frequency transducers in the detection of liver metastases

BACKGROUND AND AIMS

To evaluate the benefit of the additional use of a high frequency ultrasound probe (7.5 MHz) in finding suspicious liver lesions compared to the examination using a 3.5-MHz transducer only.

PATIENTS AND METHODS

One hundred and fifty-seven patients with underlying malignant disease were examined with both transducers using one of three ultrasound machines (Siemens Sonoline Elegra, GE Healthcare Logic 9, or Hitachi EUB-8500). Findings on hepatic lesions were collected on a standardised documentation sheet and evaluated by descriptive statistics.

RESULTS

Ninety-three patients (59.2% of all patients) showed no evident liver lesion on conventional ultrasound with the 3.5 MHz probe. In 29 patients (18.5%) new suspicious liver lesions were found by using the high frequency transducer. Thirteen of these 29 patients (44.8%) were suspected to suffer from diffuse infiltration of the liver with malignant lesions or at least 10 additional visible lesions. In 14 patients, no liver lesion had been known before high frequency ultrasound examination. The size of newly described liver lesions ranged from 2 mm to 1.5 cm. Time needed for the additional examination with the high frequency transducer ranged between 1 and 15 min with an average of 4.0 min.

CONCLUSION

The additional use of a high frequency transducer in patients with underlying malignant disease slightly extends the examination time, but reveals new, potentially malignant hepatic lesions in almost every fifth patient.

[Fatal outcome of varicella zoster sepsis in a 22-year old patient]

Infection with Varicella zoster virus (VZV) usually occurs in children up to 15 years with mild symptoms. We present a case of a 22-year old man with a fatal varicella zoster infection. He developed fulminant hepatitis with acute liver failure and an acute respiratory distress syndrom (ARDS). In this article the general aspects of VZV infection are discussed. Treatment options and previous publications are reviewed.

Barrett's esophagus: a discrepancy between macroscopic and histological diagnosis

BACKGROUND AND STUDY AIMS

The diagnosis of Barrett's esophagus at present requires endoscopic and histological confirmation of specialized intestinal metaplasia. This study prospectively analyzed the endoscopic and histological prevalence of Barrett's esophagus and the risk factors for the presence of Barrett's esophagus among patients being treated in an endoscopy unit.

PATIENTS AND METHODS

A total of 474 unselected patients (58% men; mean age 52 y) were included in the study. Two biopsy specimens each were taken from below and above the squamocolumnar junction and from the antrum and gastric body. Four-quadrant biopsies were taken every 1-2 cm to confirm a macroscopic suspicion of Barrett's esophagus.

RESULTS

Barrett's esophagus was suspected at endoscopy in 109 patients (23%). Of the 109 patients with endoscopically suspected Barrett's esophagus, only 46 (42%) had the finding confirmed histologically. The sensitivity and specificity for the endoscopic diagnosis of Barrett's esophagus were 62% and 84%, respectively. A multivariate logistic regression analysis identified age (P = 0.0001; odds ratio per life-year 1.087; 95% CI, 1.046-1.139), male sex (P = 0.0020; OR 6.346; 95% CI, 2.094-22.314), and the number of biopsies (P = 0.0025; OR 1.661; 95% CI, 1.247-2.392) as factors associated with evidence of intestinal metaplasia on biopsy.

CONCLUSION

The striking discrepancy between the endoscopic findings and the histological diagnosis may be due to the focal distribution of intestinal metaplasia. This emphasizes the importance of an adequate biopsy protocol. In addition, better methods of detecting focal islands of intestinal metaplasia that are not visible at conventional endoscopy are needed.

[Sonographic controlled drainage of a fluid formation of the spleen in combination with pancreatitis]

With regard to acute or chronic pancreatitis various complications involving the spleen can occur, hematoma of the spleen being a rare complication. We describe the case of a patient in reduced general condition with elevated pancreatic enzymes and signs of inflammation. During multiple examinations, hematoma of the spleen, as well as hematomas close to the left adrenal gland and a larger hematoma close to the gastric wall were detected. In computed tomography and due to the laboratory parameters a pancreatitis was diagnosed. After CT-controlled puncture a communication between both formations was considered possible which was in retrospect CT-assisted not successful. Subsequently an ultrasound controlled drainage was performed, finally resulting in a restitutio ad integrum, thereby avoiding splenectomy. The described percutaneous puncture of a fluid formation in the splenic area represents a non-surgical option in the therapy of intrasplenic pancreatic fluid formations.

Interferon gamma downregulates IL-8 production in primary human colonic epithelial cells without induction of apoptosis

BACKGROUND

In acute or chronic inflammatory bowel disease (IBD) interferon gamma (IFNgamma) is still considered to be an important pro-inflammatory mediator. In the present study we investigated the impact of IFNgamma on interleukin-8 (IL-8) production as a read-out for cell activation in intestinal epithelial cell (IEC) lines and primary human colonic epithelial cells (CEC).

METHODS

Primary cultures of human CEC were established from the mucosa of patients without inflammatory disease. CEC, HT-29 or Caco-2 cells were incubated with either IFNgamma, tumor necrosis factor (TNF)alpha or IL-10. IL-8 and IL-1Ra secretion was determined by ELISA. Competicon PCR was used for quantification of IL-8mRNA. Apoptosis was quantified by propidium iodine incorporation and fluorescence activated cell sorting (FACS) analysis.

RESULTS

In contrast to HT-29 cells in primary human CEC 100 U/ml IFNgamma inhibited IL-8 secretion significantly to 70+/-15% of unstimulated primary CEC (p<0.005) more effectively than IL-10 (87+/-21% versus unstimulated cells, n.s.). In HT-29 cells, IL-8 secretion was induced to 405+/-101% of unstimulated cells. In Caco-2 cells, IFNgamma had no significant effect on IL-8 secretion. The effect in HT-29 and CEC was concentration dependent. In primary CEC, 200 U/ml IFNgamma further reduced IL-8 secretion to 48+/-18% of unstimulated CEC (p<0.05). Whereas IL-8 mRNA was strongly upregulated in HT-29 cells, no upregulation or even a downregulation was found in CEC. Pre-incubation with 100 U/ml IFNgamma did not increase the susceptibility to apoptosis mediated by anti-Fas antibody (CH-11) in primary CEC, whereas HT-29 cells showed increased rates of apoptosis after priming with IFNgamma.

CONCLUSION

In contrast to HT-29, IFNgamma downregulated IL-8 secretion and did not induce IL-8 mRNA expression in primary human CEC. This effect was not due to induction of apoptosis.

Contrast-enhanced ultrasound allows for interventions of hepatic lesions which are invisible on convential B-mode

BACKGROUND AND AIMS

Contrast harmonic imaging significantly increases the detectability of liver lesions which are invisible on conventional B-mode sonography. With the introduction of contrast agents, which can be visualized at low mechanical index (low-MI), continuous real time observation of liver lesions under contrast conditions is possible. We addressed the question whether contrast-enhanced sonography allows for intervention of hepatic lesions impossible to detect on conventional B-mode imaging.

PATIENTS AND METHODS

We evaluated twelve patients with hepatic tumors or abscesses, which could not be analyzed and punctured under fundamental B-mode guidance. The ultrasound contrast agent BRI was used for detection of the hepatic lesions under contrast harmonic imaging (CHI) conditions with phase inversion at low-MI.

RESULTS

In eleven out of twelve patients interventions under CHI conditions were successful, as proven by histological, microbiological or tumor marker analysis. The puncture needles were visible in all cases. With an algorithm for optimizing the puncture conditions at low-MI CHI the biopsies can be performed in two steps.

CONCLUSIONS

Our results show that biopsies of liver lesions under real-time continuous CHI at low-MI are feasible.

[Evaluation of intestinal hyperaemia in inflamed bowel by high resolution Contrast Harmonic Imaging (CHI)]

AIM

Intestinal hyperaemia is a sign of active disease in the inflamed intestine which can be detected by Doppler sonography. This technique, however, can be jeopardized by tissue motion artefacts (peristalsis), and intramural enteric vessel perfusion may be below the detection threshold. Visualisation of vessels by Contrast Harmonic Imaging (CHI) at a low Mechanical Index (low MI) is not restricted by the limitations mentioned above. Contrast Harmonic Imaging at low MI of the intestinal wall has not yet been described with high frequency probes. We therefore evaluated the validity of this method for detecting hyperaemia of the intestinal wall.

METHODS

CHI at low MI was performed with a 7.5 MHz ultrasound probe in 12 patients with signs of an inflamed intestine. The contrast agent BR 1 (4.8 ml) was injected intravenously. Contrast enhancement was quantified by analysing gray scale values before and after injection of BR 1 in regions of interest within the submucosal layer.

RESULTS

At about 15 sec. after injection of BR 1, arterial inflow of the contrast agent with visualisation of the feeding mesenteric vessels and intense contrast of the submucosal lamina could be observed. An increase of the gray scale values within the ROI after contrast enhancement was detected in all patients.

CONCLUSION

We have shown that CHI at low MI is technically feasible for the demonstration of increased intestinal perfusion in inflammatory bowel disease by using a high resolution ultrasound probe. One possible method of quantifying the contrast enhancement is the gray scale analysis of pixels in defined regions of interest within the submucosal layer.

Endoskopische Mukosaresektion eines Ösophagusfrühkarzinoms bei Leberzirrhose und Ösophagusvarizen

Squamous cell carcinomas account for more than 80 % of esophageal malignancies in Germany. Alcohol and tobacco smoke are two of the most important risk factors. In superficial esophageal squamous cell carcinoma, endoscopic mucosal resection (EMR) is a very useful and effective treatment modality. However, in patients with submucosal esophageal cancer, radical esophageal resection is regarded as the gold standard for treatment at present. We report the case of a 71-year-old female patient with alcohol-induced liver cirrhosis with esophageal varices and a - therefore inoperable - early esophageal squamous cell carcinoma. Photodynamic therapy (PDT) using 5-aminolevulinic acid (5-ALA) seemed not to be an effective treatment modality due to its limited penetration depth (< 2 mm) and the liver toxicity of 5-ALA. PDT using Photofrin(R) with a higher penetration depth seemed to be associated with a high risk of bleeding due to the esophageal varices. Furthermore, this sensitizer is associated with a high rate of strictures and a long-lasting skin sensitivity. In contrast, arguments against an endoscopic mucosal resection (EMR) were endosonographically suspected submucosal tumor growth and a high risk of bleeding. Nevertheless, with respect to the lack alternatives we decided to perform an EMR after ligation of esophageal varices. The tumor could be resected in sano without major bleeding complication. Histology demonstrated a carcinoma in situ without submucosal invasion. After 3 months a second EMR was necessary due to recurrence. Meanwhile after a follow-up period of 18 months only low grade intraepithelial neoplasia without macroscopically suspicious lesions was observed.

Effekte des ärztlichen Controllings auf die DRG-gerechte Diagnosenverschlüsselung

OBJECTIVE

In a prospective study we analysed the quality of ICD-coding in clinical everyday life of a department for internal medicine.

METHODS

A skilled intern--the so-called DRG assistant--was temporarily released from clinical work. Over nine weeks he had to control all diagnoses contemporaneously that were ICD-coded by his colleagues on admission and discharge of their patients. The DRG-assistant had to ask for missing or correct implausible diagnoses, or inappropriate ICD-coding and with it also train his colleagues in appropriate coding. The effects of the DRG-assistant's correction of coding, on DRG-consistent grouping and on the potential financial loss or benefit generated by his work were recorded. After stoppage of this control in a subsequent phase of the study the effect of the absence of the DRG-assistant, the absence of reminders and coding control and the changes of the clinic's revenue were determined.

RESULTS

Corrections of ICD-coding by the DRG-assistant alone caused a remarkable increase in case-mix-index (CMI). CMI's mean value increased from 1.76 to 1.84 and the clinic's revenue increased by 180 Euro per patient (a total of about 80,000 Euro in nine weeks). After the end of the control, the case-mix-index dropped within three weeks down to 1.14, corresponding with a potential loss of 1200 Euro per patient (assuming that patients' morbidity was the same over the time of the study). Coding corrections could not improve CMI in this situation.

CONCLUSION

Contemporaneous control of ICD-coding by physicians seems to be essential in DRG based accounting.

[Evaluation of a new, portable ultrasound system in routine clinical use]

AIM

Evaluation of a new, hand-carried ultrasound system (SonoSite 180) for routine use at a university hospital.

METHODS

101 routine ultrasound examinations were performed as bedside examinations on the wards or in the ultrasound centre by three experienced sonographers. The quality and results of examinations using the SonoSite 180 were evaluated in a standardized questionnaire.

RESULTS

in 89 % of the ultrasound examinations, results were at least satisfactory. Even though the examiners felt some uncertainty due to the small screen, especially while performing abdominal scans, small lesions which were located far from the scanner were readily identified.

CONCLUSION

Routine ultrasound examinations yield satisfactory results when performed with the new, hand-carried ultrasound system. The low size and weight of this ultrasound system and its good image quality makes it a very usefull tool, especially for examinations of patients at intensive care units and on hospital wards.

[A new paracentesis needle for ascites and pleural effusion compared with the venous indwelling catheter. A prospective, randomized study]

BACKGROUND

Diagnostic or therapeutic paracentesis of ascites or pleural effusions is part of the daily routine on many hospital wards and in outpatient clinics. In Germany, paracentesis is usually performed with angiocaths. However, the therapeutic large volume paracentesis of ascites and paracentesis of pleural effusions with angiocaths is often cumbersome and quite often paracentesis fails, forcing the physician to repuncture. This is mainly due to the fact that angiocaths are not designed for such interventions.

PATIENTS AND METHOD

45 patients with ascites or pleural effusions were treated with a new needle specially designed for paracentesis, or with an angiocath. The new paracentesis needle was compared with the angiocath needle under the following aspects: necessity and number of positional corrections of the needle, necessity of and reasons for repuncture, duration of puncture, flow capacity, subjective practicability of paracentesis and patient acceptance of the paracentesis needle.

RESULTS

The paracentesis needle was superior to the angiocath in all investigated respects. Significantly, the paracentesis needle had a much higher success rate in the complete drainage than had the angiocath.

CONCLUSION

The paracentesis needle was objectively superior as compared to the angiocath. It might help to avoid additional complications due to repuncture and it will increase the patients' comfort.

[Intercostal percutaneous ultrasound guided decompressive gastrostomy (PUG)--a case report]

Percutaneous gastrostomies (PG) are nowadays usually placed endoscopically (PEG). Due to stenoses in the pharynx or the esophagus or in case of a lack of diaphany, other methods for the placement of PG such as computed tomography (CT-) guided or ultrasound-guided PG (PUG) are performed. We present a case of a 63-year old male patient with a retroperitoneal liposarcoma and multivisceral resection who presented with the symptoms and signs of an ileus due to metastatic occlusion of the small bowel. The placement of a decompression-PEG was impossible due to interposition of colon between the stomach and the abdominal wall. After filling the stomach with water via a naso-gastral decompression tube, the stomach could be visualized at the left thoracic wall, since the spleen and the left kidney had been removed at prior surgery. A transcostal decompression-PUG was inserted. The intervention described is the first published ultrasound guided transcostal decompression gastrostomy and is an example for the growing significance of interventional ultrasound.

Prevalence of markers of hepatitis B in the adult German population

The prevalence of hepatitis B virus markers was investigated in 5305 individuals considered to be representative for the adult German population. After adjustment of the data according to the age and sex distribution in the whole German population an anti-HBc prevalence of 8.71% (95% confidence interval, 7.94-9.48%) and an HBsAg carrier rate of 0.62% (95% confidence interval, 0.40-0.84%) were calculated. Anti-HBc prevalence increased with age from 4.12% in the youngest group to 15.66% in the 61-70-year-old. The percentage of HBsAg carriers showed a maximum of 1.12% in the 41-50-year-old individuals and decreased significantly in the older age groups. 1.40% (95% confidence interval, 1.08-1.72%) of individuals had anti-HBc only. There was a trend to higher rates of this pattern in males than in females; a significantly higher percentage of persons with anti-HBc only was found in anti-HBc-positive individuals below 31 years than in older individuals. Five participants with anti-HBc only (7.7%, or about 0.1% of the whole population) showed HBV-DNA despite the absence of HBsAg. 3.1% of anti-HBc positive individuals where also positive for anti-HCV, that was significantly higher than the percentage of anti-HCV-positives among persons without any HBV marker (0.46%). This study provides a comprehensive picture of the current hepatitis B situation in Germany, showing new data especially on the distribution of HBsAg in the general population and on the subgroup of individuals with anti-HBc only.

Role of endoscopy in the staging of esophageal and gastric cancer

Progress in instrumentation and clinical research continues to expand the potential utility of endoscopic ultrasound (EUS) in the treatment of esophageal and gastric cancer. This review focuses on the role of EUS in the staging and treatment planning of patients with esophageal and gastric cancer.

[The sonographic picture of an echogenic liver is an indicator of pathologic glucose tolerance]

BACKGROUND

Almost all patients in departments of internal medicine routinely undergo abdominal ultrasound examination in which liver changes indicating hepatic steatosis are often detected. The aim of this study was to assess the occurrence of pathological oral glucose tolerance, manifest diabetes mellitus and other changes indicative of a metabolic syndrome in patients with sonographic signs of hepatic steatosis.

PATIENTS AND METHODS

577 patients were examined during a period of 6 months: 90 patients fulfilled the inclusion criteria.

RESULTS

Among the 90 patients with echodense liver who were included in the study (42 female, 48 male) 36 patients presented with previous diagnosis of diabetes mellitus (40%). The oral glucose tolerance test was impaired in 19 patients (21%) and in four patients with manifest diabetes mellitus (4%). Among patients with echodense liver a high percentage presented with obesity and impaired fat metabolism.

CONCLUSIONS

The large number of patients with an impaired oral glucose tolerance test converting to manifest diabetes, as well as the large number of patients with manifest disorders of fat metabolism suggest that screening for diabetes should be performed in patients who present with sonographic signs of hepatic steatosis.

Activation of the IL-4 STAT pathway in rheumatoid synovium

STATs act as second messenger after binding of a signaling molecule to its receptor. IL-4 STAT is directly involved in the IL-4-dependent gene transcription in the nucleus. We examined the expression and activation of IL-4 STAT and its related kinase Jak-1 in rheumatoid synovium. Rheumatoid arthritis (RA) synovial frozen sections of patients with short-term (<1 year) and long-term disease (>2 years) were examined using in situ hybridization and immunohistochemistry. IL-4 STAT mRNA could be detected in synovium of patients with short-term and long-term RA. The most intensive expression of IL-4 STAT mRNA could be seen in follicular inflammatory infiltrates. In the synovial lining, both fibroblasts and macrophages expressed IL-4 STAT mRNA. IL-4 STAT and Jak-1 protein was expressed by synoviocytes, and up-regulation could be induced after stimulation with IL-4. Activation of IL-4 STAT was reflected by phosphorylation of IL-4 STAT. The results indicate that IL-4 STAT is involved in key pathomechanisms in RA synovium and that IL-4 STAT-dependent pathways operate in early and late stages of the disease and presumably contribute to inhibitory immune mechanisms in RA synovium.

Prevalence of antibodies against hepatitis C virus in the adult German population

OBJECTIVE

The prevalence of anti-HCV in Germany has been determined for blood donors and certain risk groups, but the burden of disease in the general population remains unknown. The aim of this study was to determine the prevalence of anti-HCV in a study group representing the normal adult German population.

DESIGN

A total of 5312 individuals aged 18-70 years were randomly selected from small, middle-sized and big cities in five different German states. Sera were tested for anti-HCV by enzyme immunoassay and immuno dot assay, as well as for anti-HBc and, in the case of a positive result, for anti-HBs and HBsAg. Serological typing was performed in anti-HCV-positive persons.

RESULTS

Thirty-nine individuals were anti-HCV positive; indeterminate results (with antibodies against the viral core protein only) were obtained in 20. There was a tendency to higher prevalence rates with increasing age as well as to a higher prevalence in women. Serological typing revealed the presence of genotype 1 in the vast majority of participants (82%); only a minority showed genotype 3 (7.2%) or other genotypes (7.2%). Markers of HBV were seen in 43.6% of the anti-HCV positive individuals, with nearly one third (29.4%) of the double-infected showing anti-HBc as the only marker for HBV.

CONCLUSIONS

According to our data, an anti-HCV prevalence of 0.63% (95% confidence interval, CI, 0.42-0.84%) can be assumed in the general adult German population, with higher values in older people and women. Nearly half of the anti-HCV positive individuals also show markers of hepatitis B virus.

Effect of human C-reactive protein on chemokine and chemotactic factor-induced neutrophil chemotaxis and signaling

C-reactive protein (CRP) is a unique serum pentraxin and the prototype acute phase reactant. CRP is a ligand for specific receptors on phagocytic leukocytes, and mediates activation reactions of monocytes/macrophages, but inhibits the respiratory burst of neutrophils (PMN). Since CRP selectively accumulates at inflammatory sites in which IL-8 is also produced, we tested the effects of CRP on the responsiveness of PMN to IL-8 and the bacterial chemotactic peptide, FMLP-phenylalanine (FMLPP). Purified human CRP inhibited the chemotactic response of PMN to IL-8 and FMLPP. A mouse IgM mAb that was generated against the leukocyte CRP receptor (CRP-R) also inhibited the chemotactic response. Incubation of purified CRP with activated PMN generated CRP-derived peptides that also inhibited chemotaxis. A synthetic CRP peptide (residues 27-38) that binds to the CRP-R had weak chemotactic activity, whereas two other CRP synthetic peptides (residues 174-185 and 191-205) inhibited chemotaxis of PMNs to both IL-8 and FMLPP. CRP did not alter receptor-specific binding of IL-8, but exerted its effect at the level of signaling. CRP augmented both IL-8- and FMLPP-induced mitogen-activated protein kinase (extracellular signal-regulated kinase-2) activity. CRP at acute phase levels increased both agonist-induced and noninduced phosphatidylinositol-3 kinase activity. The results suggest a role for CRP as a regulator of leukocyte infiltration at inflammatory sites.

L-selectin activates the Ras pathway via the tyrosine kinase p56lck

Selectins mediate rolling, the initial step of leukocyte adhesion to endothelial cells [Springer, T. A. (1995) Annu. Rev. Physiol. 57, 827-872 and Butcher, E. C. (1991) Cell 67, 1033-1036]. In this study we show that L-selectin triggering of Jurkat cells using different antibodies or glycomimetics resulted in activation of the src-tyrosine kinase p56lck; tyrosine phosphorylation of intracellular proteins, in particular mitogen-activating protein kinase and L-selectin; and association of Grb2/Sos with L-selectin. This association correlated with an activation of p21Ras, mitogen-activating protein kinase, Rac2, and a transient increase of 2-O synthesis. Stimulation of the Ras pathway by L-selectin requires functional p56lck, since p56lck-deficient Jurkat cells (JCaM1.6) do not show tyrosine phosphorylation, association of L-selectin with Grb2/Sos, and activation of Ras upon L-selectin triggering. Transfection of JCaM1.6 cells with p56lck reconstitutes the observed signaling events. Genetic inhibition of Ras or Rac2 prevented Rac2 stimulation and 2-O synthesis, respectively. The specificity and the physiological significance of the observed signaling cascade is indicated by stimulation of L-selectin-transfected P815, L-selectin-positive CEM or peripheral blood lymphocytes resulting in the same activation events as in Jurkat cells. Our results point to a signaling cascade from L-selectin via p56lck, Grb2/Sos, Ras, and Rac2 to 2-O.

Fas-induced apoptosis is mediated by activation of a Ras and Rac protein-regulated signaling pathway

Fas induces apoptosis in lymphocytes via a poorly defined intracellular signaling mechanism. We and others have previously demonstrated the involvement and significance of a signaling cascade from the Fas receptor via sphingomyelinases and ceramide to Ras in apoptosis (Gulbins, E., Bissonette, R., Mahboubi, A., Nishioka, W., Brunner, T., Baier G., Baier-Bitterlich, G., Byrd, C., Lang, F., Kolesnick, R., Altman, A., and Green, D. (1995) Immunity 2, 341; Cifone, M. G., DeMaria, R., Roncali, P., Rippo, M. R., Azuma, M., Lanier, L. L., Santoni, A., and Testi, R. (1994) J. Exp. Med. 180, 1547-1552; Gill, B. M., Nishikata, H., Chan, G., Delovitch, T. L., and Ochi, A. (1994) Immunol. Rev. 142, 113-126). Here, we demonstrate an activation of the small G-proteins Rac 1 and Rac 2 after Fas receptor triggering. Expression of a transdominant inhibitory Ras mutant (N17Ras) prevents Rac 1 and Rac 2 stimulation, suggesting a signaling cascade from the Fas receptor via Ras to Rac 1 and Rac 2. Genetic and pharmacological inhibition of Ras or Rac 1 and Rac 2 stimulation blocks Fas-induced apoptosis, pointing to an important function of a Ras and Rac protein-regulated signaling pathway in Fas-mediated programmed cell death.

Activation of the Ras signaling pathway by the CD40 receptor

The CD40 receptor is an important molecule regulating B lymphocyte proliferation, maturation, Ab class switching, and cell survival. In the present study, we identified signal transduction events triggered by cross-linking the CD40 receptor. Stimulation of Daudi B cells with anti-CD40 resulted in activation of p21ras, an important switch point in the regulation of cell growth and differentiation. Ras activation correlated with a stimulation of Rac1 and MEK-1 as well as tyrosine phosphorylation of phosphatidylinositol 3-kinase. Inhibition of endogenous Ras by transfection of transdominant inhibitory Ras prevented tyrosine phosphorylation or stimulation of phosphatidylinositol 3-kinase, Rac1, or MEK-1 upon CD40 receptor triggering, proving an activation of the Ras pathway by CD40. Ras activation was partially inhibited by either herbimycin A or calphostin pretreatment and completely inhibited by preincubation with a combination of both inhibitors, indicating a synergistic role for protein tyrosine kinases and diglycerides in Ras activation after CD40 stimulation. In support of a role for diglycerides, we detected a 30 +/- 5% decrease of cellular phosphatidylcholine content, correlating with a threefold increase of diacylglycerol synthesis induced by CD40. Supporting a role for protein tyrosine kinase, we measured a five- to eightfold stimulation of p56lyn and p58blk kinase activity. These results suggest the activation of the Ras pathway via an additive function of src kinases and phospholipases that may be important in the mediation of biologic effects after CD40 receptor engagement.

Activation of the Ras signaling pathway by the CD40 receptor

The CD40 receptor is an important molecule regulating B lymphocyte proliferation, maturation, Ab class switching, and cell survival. In the present study, we identified signal transduction events triggered by cross-linking the CD40 receptor. Stimulation of Daudi B cells with anti-CD40 resulted in activation of p21ras, an important switch point in the regulation of cell growth and differentiation. Ras activation correlated with a stimulation of Rac1 and MEK-1 as well as tyrosine phosphorylation of phosphatidylinositol 3-kinase. Inhibition of endogenous Ras by transfection of transdominant inhibitory Ras prevented tyrosine phosphorylation or stimulation of phosphatidylinositol 3-kinase, Rac1, or MEK-1 upon CD40 receptor triggering, proving an activation of the Ras pathway by CD40. Ras activation was partially inhibited by either herbimycin A or calphostin pretreatment and completely inhibited by preincubation with a combination of both inhibitors, indicating a synergistic role for protein tyrosine kinases and diglycerides in Ras activation after CD40 stimulation. In support of a role for diglycerides, we detected a 30 +/- 5% decrease of cellular phosphatidylcholine content, correlating with a threefold increase of diacylglycerol synthesis induced by CD40. Supporting a role for protein tyrosine kinase, we measured a five- to eightfold stimulation of p56lyn and p58blk kinase activity. These results suggest the activation of the Ras pathway via an additive function of src kinases and phospholipases that may be important in the mediation of biologic effects after CD40 receptor engagement.

Fas-induced programmed cell death is mediated by a Ras-regulated O2- synthesis

Fas induces apoptosis in lymphocytes via a poorly defined intracellular signalling cascade. Previously, we have demonstrated the involvement and significance of a signalling cascade from the Fas receptor via sphingomyelinases and ceramide to Ras in Fas-induced apoptosis. Here we demonstrate rapid and transient synthesis of reactive oxygen intermediates (ROI) via activation of Ras after Fas. Genetic inhibition of Ras by transfection of transdominant inhibitory N17Ras blocked Fas-mediated ROI synthesis and programmed cell death. Likewise, the antioxidants N-acetyl-cysteine and N-t-butyl-phenylnitrone abolished Fas-induced cell death, pointing to an important role for Ras-triggered ROI synthesis in Fas-mediated programmed cell death.

Tyrosine phosphorylation-dependent suppression of a voltage-gated K+ channel in T lymphocytes upon Fas stimulation

Selective cell death plays a critical role in the development of the immune system and in the elimination of target cells expressing foreign antigens. Most of programmed cell death occurs by apoptosis. Apoptotic cell death of lymphocytes can be triggered by ligation of APO-1/Fas (CD95) antigen (Suda, T., and Nagata, S. (1994) J. Exp. Med. 179, 873-879; Nagata, S., and Golstein, P. (1995) Science 267, 1449-1456). We find that activation of Fas leads to the inhibition of the voltage-dependent n-type K+ channels (Kv1.3) studied by patch clamp technique in Jurkat T lymphocytes. Tyrosine kinases have been shown to be crucial in Fas-induced cell death (Eischen, C. M., Dick, C. J., and Leibson, P. J. (1994) J. Immunol. 153, 1947-1954). The inhibition of the current is correlated with the tyrosine phosphorylation of immunoprecipitated and blotted K+ channel protein. We show, that the Src-like protein-tyrosine kinase inhibitor herbimycin A and the deficiency of the p56(lck) tyrosine kinase in mutant Jurkat cells abolished the channel inhibition and phosphorylation by anti-Fas antibody, while reconstitution of the p56(lck) kinase partly restored these effects of Fas receptor triggering. These results suggest a regulation of n-type K+ channels by tyrosine kinases upon Fas receptor triggering, which might be important for apoptosis.

Negative signaling via FcgammaRIIB1 in B cells blocks phospholipase Cgamma2 tyrosine phosphorylation but not Syk or Lyn activation

Crosslinking of the B cell antigen receptor surface immunoglobulin induces tyrosine phosphorylation and activation of the Src family and Syk tyrosine protein kinases, tyrosine phosphorylation of phospholipase Cgamma2 (PLCgamma2) and increases in intracellular second messengers inositol phosphates and Ca2+. These activation events, in conjunction with other pathways, culminate in the induction of B cell proliferation and differentiation. In contrast, co-crosslinking surface Ig with the B cell IgG Fc receptor prevents many of these activation events, including B cell proliferation and differentiation. The precise nature of the negative signal(s) derived from Fc receptors that prevent B cell activation is not known. Here, early activation events were examined in B cells stimulated via the antigen receptor alone or under co-crosslinking conditions. The data indicated a selective block in the tyrosine phosphorylation and activation of PLCgamma2 but not in activation of the upstream kinases, Syk and Lyn, under co-crosslinking conditions. We conclude that the negative signal acts directly on PLCgamma2 and is consistent with recent studies describing an activation-induced association of a phosphotyrosine phosphatase with tyrosine-phosphorylated B cell Fc receptor.

Molecular analysis of Ras activation by tyrosine phosphorylated Vav

Vav has been shown to activate Ras (1-3) and is regulated by tyrosine phosphorylation (1) or binding of diglycerides (3) to the cysteine rich domain. In the present study employing different Ras activation assay techniques using [3H]GDP release or [32P]alpha GTP-binding from membrane-bound or soluble recombinant Ras, we demonstrate that Ras activity can be increased by tyrosine phosphorylated Vav upon cellular stimulation via the IL-2 receptor or the TCR/CD3-complex. Increase of [32P]alpha GTP-binding to Ras catalyzed by phosphorylated Vav is similar to the activity of immunoprecipitated Sos. The activity of Vav measured by binding of [32P]alpha GTP to Ras was linear with respect to the concentration of Vav protein used. To study molecular characteristics of this Vav-Ras interaction, we used several Ras mutants and demonstrate that Vav activity towards Ras depends on the integrity of the same or similar domains as Ras activation by SDC 25 or CDC 25.

Effects of systemic complement activation on renal circulation of rats

In a variety of immunopathological diseases activation of the complement cascade occurs either systemically or localized in the kidney. To elucidate the functional impact of complement activation upon the renal microcirculation, we administered cobra venom factor of Naja naja kaouthia (CVF) i.v. into thiobarbital anaesthetized female rats. CVF is a potent activator of the alternative pathway of complement by forming the C3-convertase CVF, Bb which cannot be downregulated by the natural inhibitor factors H and I and thereby leads to generation of the anaphylatoxins C3a and C5a and formation of the membrane attack complex (MAC). We utilized creatinine clearance and flowmeter measurements in the normal kidney and intravital microscopy of the split hydronephrotic rat kidney model to observe the microvascular changes. Bolus injection of CVF (100 U kg-1) resulted in an immediate reduction of RBF (-68% after 10 min), which remained decreased during the entire experiment (90 min). Systemic blood pressure was significantly reduced only in the early period (-23% of control: 126 mmHg after 10 min). After an initial anuric phase of 30 min duration, the glomerular filtration rate was significantly diminished by 47%. White cell count was decreased by about 50% after the experiments. Application of the competitive thromboxane A2-antagonist, BM 13505, reversed all renal and systemic CVF-effects. Continuous infusion of the competitive leukotriene D4-antagonist, ICI 198615, attenuated the late renal CVF-effects (i.e. 30 min after injection of CVF). Depletion of polymorphonuclear cells (PMN) attenuated the CVF-effects similar to BM 13505. Intravenous administration of CVF in the hydronephrotic kidney model resulted in a massive constriction of the interlobar and arcuate artery, with a fall in glomerular blood flow comparable to the reduction of RBF in the normal kidney. Diameters of the afferent arterioles--most sensitive to many vasoconstricting agents--were not significantly altered. Our results suggest that injection of CVF and the liberation of high amounts of the anaphylatoxins, C3a and C5a, induces the release of TXA2, which contributes to the early renal effects and the formation of cysteinyl-leukotrienes which play an important role in the late phase of systemic complement activation. Utilizing the split hydronephrotic kidney model we demonstrated the predominant action of complement activation on the large preglomerular vessels for the first time. PMN are seemingly involved in the liberation of secondary mediators which appear to reduce renal blood flow and glomerular filtration.

Endothelin and endothelium-derived relaxing factor control of basal renovascular tone in hydronephrotic rat kidneys

1. In order to investigate the control of renal vascular tone by endothelin (ET) and endothelium-derived relaxing factor (EDRF) under basal conditions, we infused intravenously anti-ET-1/3 antibodies (a-ET-1/3) and NG-nitro-L-arginine methyl ester (L-NAME) in split hydronephrotic rat kidneys. 2. A 25 min I.V. infusion of a-ET-1/3 (4.0 x 10(-13) mol kg-1 min-1) induced a time-dependent vasodilatation of arcuate (16.5%) and interlobular arteries (18.6%) as well as an increase of glomerular blood flow (GBF) by 32%. 3. Inhibition of EDRF synthesis by L-NAME produced a marked vasoconstriction of arcuate arteries (17.1%) and efferent (20.1%) arterioles and a decrease of GBF by 43%. 4. Co-infusion of a-ET-1/3 and L-NAME induced efferent vasoconstriction by 19.5%, whereas preglomerular vessel diameters remained unchanged. 5. The specificity of a-ET-1/3 effects was confirmed by simultaneous I.V. application of a-ET-1/3 and ET-1 (160 ng I.V.) which produced no significant vascular effects. Injection of ET-1 alone constricted arcuate arteries and decreased glomerular blood flow by 25%. 6. Experiments in normal rat kidneys with a-ET-1/3 I.V. revealed an increase of renal blood flow by 21%. 7. Our results demonstrate a physiological control of basal vascular tone in larger preglomerular arterioles by ET and EDRF. Efferent arteriolar tone is predominantly controlled by EDRF.

Effects of rC5a on the circulation of normal and split hydronephrotic rat kidneys

Systemic release of complement-derived anaphylatoxin C5a is suggested to be involved in the pathogenesis of renal failure during endotoxic or severe traumatic shock. In the present study we analyzed renal hemodynamic effects of recombinant human complement 5a (rC5a) and examined whether these effects are mediated by the secondary release of other inflammatory mediators. Intravenous infusion of rC5a (0.5 micrograms/min) in thiobarbital-anesthetized rats decreased renal blood flow (RBF) by 20 and 34% after 20 and 60 min, respectively. Glomerular filtration rate (GFR) was reduced by 45%, whereas filtration fraction and blood pressure were not significantly changed by rC5a. Hematocrit (Hct) increased by 11%, whereas white blood cell count decreased by 40%. Renal rC5a effects were completely inhibited by the competitive leukotriene D4/E4 antagonist ICI-198615, whereas the competitive thromboxane A2 (TxA2) antagonist daltroban only partly reversed rC5a effects on RBF and GFR. The competitive platelet-activating factor (PAF) antagonist L-695989 did not influence renal or systemic rC5a effects. These results point to an rC5a-mediated synthesis and release of cysteinyl leukotrienes and TxA2, whereas PAF does not seem to be released after intravenous rC5a in rats. To determine the cellular source of cysteinyl-leukotriene synthesis, rats were depleted of polymorphonuclear cells (PMN) by intraperitoneal injection of anti-rat PMN antibodies, which abrogated renal and systemic hemodynamic rC5a effects, suggesting that PMN participate in the synthesis and release of cysteinyl leukotrienes. The exact localization of renovascular rC5a effects was performed on the model of the split hydronephrotic rat kidney.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of endothelin on the renal microcirculation of the split hydronephrotic rat kidney

We have examined the effects of endothelin (ET) on the renal microcirculation by in vivo microscopy using the model of the split hydronephrotic rat kidney. ET, a potent vasoconstrictor peptide synthesized by vascular endothelial cells, showed marked and long-lasting effects on glomerular blood flow and vessel diameters in various segments of the renal vascular bed. Intravenously applied ET (100 ng/min/kg) increased systemic blood pressure from 123 +/- 7 to 156 +/- 4 mm Hg, decreased glomerular blood flow by 70%, and preferentially constricted larger preglomerular vessels, e.g. the arcuate artery. The competitive leukotriene antagonist FPL55712 significantly attenuated the vasoconstrictor response of the larger vessels. Local ET administration decreased glomerular blood flow in a dose-dependent manner (50% reduction at a concentration of 2.6 +/- 0.7 x 10(-9) M) and constricted smaller vessel segments, e.g. the afferent and efferent arterioles near the glomerulus. The constriction induced by ET was not significantly affected by the Ca2+ channel blocker nitrendipine (2.8 x 10(-6) to 1.1 x 10(-5) M). We conclude that intravenous ET effects are probably mediated by leukotrienes, inducing constriction of larger renal vessels. Locally administered ET acts directly on the renal vasculature, especially on smaller vessels.

Cysteinyl leukotriene actions on the microcirculation of the normal and split hydronephrotic rat kidney

The effects of leukotriene D4 (LTD4) and leukotriene E4 (LTE4) on renal microcirculation were determined on normal and hydronephrotic female Wistar rats. In normal kidneys, the effects of LTD4 on total renal blood flow and glomerular filtration rate were measured by a flow meter and by inulin clearance. In the split hydronephrotic kidney, the LTD4- and LTE4-mediated vascular effects were localized by intravital microscopy. Intravenous infusion of low-dose LTD4 (1 x 10(-9) mol min-1 kg-1) over 15 min induced a strong decrease in renal blood flow (-43% and -70%) in the normal and the hydronephrotic kidney. After the infusion the glomerular filtration rate of the normal kidney was significantly reduced by 65% and the filtration fraction by 32%. The fall in filtration fraction is in accordance with the significant decrease in luminal diameters of the arcuate artery (-28%) and the proximal interlobular artery (-12%) in the hydronephrotic kidney under LTD4. The decrease in renal blood flow, glomerular filtration rate, filtration fraction and luminal diameters persisted in the normal as well as in the hydronephrotic kidney for more than 60 min beyond cessation of infusion. Local application of LTD4 (1 x 10(-10) mol l-1 up to 1 x 10(-7) mol l-1) and LTE4 (1 x 10(-10) mol l-1 up to 1 x 10(-8) mol l-1) induced a dose-dependent constriction of the arcuate artery and the proximal interlobular artery. The distal interlobular artery, the afferent and the efferent arteriole were not significantly affected by LTD4 or LTE4. The glomerular blood flow was dose-dependently reduced up to 48% under local LTD4 and 43% under LTE4. The LTD4/LTE4 antagonist FPL 55712 (1 x 10(-8) mol min-1 kg-1, iv) significantly attenuated the effects of LTD4 infusion and local LTE4 application in the hydronephrotic kidney. This is indicative of the presence of receptors for LTD4 and LTE4 in the larger preglomerular vessels of the rat kidney. The LTD4 effects on the normal kidney were attenuated by simultaneous infusion of dopamine (5 microgram min-1 kg-1) or plasma expansion, two principal methods in the treatment of acute renal failure. The results in the normal and hydronephrotic kidney demonstrate a preferential preglomerular vasoconstriction under LTD4 and LTE4 causing a marked decrease in renal and glomerular blood flow, glomerular filtration rate and filtration fraction.