Growth of Heteroepitaxial Lead Chalcogenide Infrared Detector Arrays on Fluoride Coveredsilicon Substrates

Composition graded buffer layers of group Ila fluorides allow the heteroepitaxial growthof device quality narrow gap lead chalcogenides onto Si. Mechanical stresses in the layers are almost completely relaxed at room temperature despite large thermal expansion mismatches. Photovoltaic infrared sensors with up to about 9.5 um cut—off wavelengths and which operate at or near the 300K background noise limit have been fabricated in such PbTe and (Pb,Sn)Se on Si structures.

Furthermore, epitaxial graded fluoride buffers seem to be suited to connect other semiconductors with even large lattice mismatches. Initial heteroepitaxial growth of CdTe on fluoride/Si(lll) substrates (mismatch 20%) supports such more general applications.

[Prevention of colon cancer--update 2008]

Today effective prevention of colorectal cancer can be done. For primary prevention there are good data for the recommendation of regular physical activity and body weight reduction if BMI is greater than 25 kg/m(2). Furthermore colorectal cancer risk correlates with alcohol intake and the harmful role of tobacco is well documented. But the influence of nutrition seems to be small. The results of a lot of studies are inconsistent. Diets high in fiber are recommended. The intake of red or processed meat seems to be associated with a higher risk for colorectal cancer. With the additive intake of vitamins and antioxidants the risk of colorectal cancer cannot be reduced. At present the use of drugs like aspirin, NSAD or statins cannot be recommended for primary prevention. The fecal occult blood test (FOBT) is the standard of the non-invasive screening methods. But regarding sensitivity and specificity there are better results for the new immunochemical fecal occult blood tests. The TuM2-PK test is an another screening method, but seems to be inferior to the immunochemical tests. Colonoscopy is the gold standard in the prevention of colorectal cancer. But it is important to improve the acceptance of this screening method in general population.

[Functional gastrointestinal disorders]

Functional gastrointestinal disorders particularly dyspepsia an irritable bowel syndrome are frequent problems for the general practitioner and also for the specialist. Both are diseases and not only a kind of discomfort. The high frequency of dispepsia and irritable bowel syndrome induces very high direct and indirect charges. Both diseases depend on a number of factors or causes, for whom the evidence is not good. But there are good experimental data for the visceral hypersensitivity as one of the main factors. Gastroscopy is the most important examination in the diagnosis of dyspepsia. Endoscopy has to be done in all patients with alarm symptoms an in all patients older than 45 years. The therapy of dyspepsia is an empirical one. The eradication of Helicobacter pylori is a therapeutical option, but only 8% of the patients will have benefit for a long time. Other therapeutical options are the use of proton-pump inhibitors, prokinetics or phytotherapeutics. The therapy of the irritable bowel syndrome depends on the subtype of the disease (diarrhea, constipation, abdominal pain, bloating). First of all a good doctor-patient relationship is mandatory. Furthermore the use of dietary fibre, antidiarrhoeics, laxatives and muscle relaxants may be beneficial. And phytotherapeutics can be an additional therapeutic approach.

Acceptance of flexible sigmoidoscopy as a screening examination for colorectal cancer in an outpatient clinic

BACKGROUND AND STUDY AIM

Flexible sigmoidoscopy (FS) is a feasible examination technique and a suitable tool for population-based screening, but very little is known about determinants of endoscopic screening participation. The aim of this study was to determine the acceptance rate and the factors influencing the decision of participating in a screening program for patients in an outpatient clinic.

MATERIALS AND METHODS

In this prospective study, a colorectal cancer screening by FS was offered to 631 patients older than 40 years. Three strategies were available, (1) to have the endoscopy on the same day, (2) to make an appointment for another day, or (3) to take time to think about if they wanted the procedure. The reasons for refusal of the FS were documented.

RESULTS

419 of the 631 (66.4%) patients had no interest to take part in the screening program during their outpatient visit. Two hundred twelve (33.6%) patients were primarily interested on FS, but only 110 of them were finally examined. In total, 102 patients did not make an appointment for FS or did not appear for the endoscopy. The participation rate was therefore 17.4% (110/631) of all patients. Of the patients who agreed to receive an on-site examination, 78.3% were examined compared to 18.8% of patients who fixed the appointment for another day or after taking time to reflect upon the FS procedure. More male than female patients accepted the FS screening. Recommended colonoscopy was finally performed in 76%. Thirty-three polyps were found during the screening program of which 18 were larger than 0.5 cm. No CRC was detected. All patients agreed to repeat the FS every 5 years.

CONCLUSIONS

This study demonstrates that a screening examination will be most likely performed if it is done as an on-site examination. In contrast, the participation rate is low if the patient has to make an appointment by himself. Acceptance of FS screening is also dependent on the patient's gender and family history of cancer. Additional strategies are needed to further improve participation.

[Toxic megacolon--the position of the internist]

Toxic megacolon is a rare but typical complication of ulcerative colitis. But also every inflammatory bowel disease may be cause of toxic megacolon, including especially Crohn's colitis and pseudomembranous colitis (PMC). There is to mention, that PMC becomes more frequent and more important in the last years. Toxic megacolon is defined by radiological, clinical and labaratory criteria: colonic distension (<6 cm), fever, tachycardia, hypotension, electrolyte disturbances, leucocytosis and anemia. Intensive medical therapy is primarly the therapy of choice, but clinical parameters should be closely monitored. In patients with ulcerative colitis high dosis of corticosteroids are given intravenously. If there is no clinical improvement after 48 to 72 hours, colectomy is required. The use of alternative therapies like cyclosporine or infliximab has to be discussed as possible before toxic megacolon occurs.

[Gastroenterology in the elderly]

The medical care of old patients becomes more and more important. Currently about 21% of all people are older than 60 years. Decisions about therapeutical procedures often cannot be based on guidelines, because studies leading to this guidelines have normally excluded older patients. Decisions have often to be made individually in view of different factors like comorbidity and social structures. All symptoms occuring in older patients need a careful diagnostic work-up, even the majority of complaints as in younger people are of functional origin. In view of the high life expectancy and quality of life the use of difficult and expansive diagnostic and therapeutical tools are justified also in older people. So diagnostic and interventional endoscopic procedures can be done with low risk in older patients.

Mode-locked laser diode with an ultrafast integrated uni-traveling carrier saturable absorber

A novel two-section integrated mode-locked laser diode (MLLD) with a separate ultrafast uni-traveling carrier (UTC) saturable absorber section and semiconductor optical amplifier gain section is demonstrated. The UTC absorber is composed of a thin p-InGaAsP absorbing layer and an intrinsic InGaAsP collecting layer. By confining the photoexcitation process to the thin highly doped absorbing layer, the diffusion-limited hole extraction process is greatly enhanced. The investigated MLLD produces 600 fs uncompressed optical pulses at a 42 GHz repetition rate.

[Value of ultrasound and doppler sonography in chronic hepatitis and liver cirrhosis]

Ultrasound is unquestionably of great importance in the diagnosis of liver diseases due to the technical improvements of the last years. Indications for an ultrasound examination are the primary diagnosis of chronic liver disease and the screening for hepatocellular carcinoma. Apart from the diagnosis of portal hypertension in liver cirrhosis a portal vein thrombosis should be detected or excluded in cases of new or refractory ascites. The Budd-Chiari syndrome is another rare but important indication. There is a considerable improvement in the differential diagnosis of focal liver lesions especially due to contrast-enhanced sonography. Using phase-inversion harmonic sonography it is possible to detect tumor vascularity in a very sensitive manner. The accuracy of contrast-enhanced sonography is comparable with helical-CT or MRT, and contrast-enhanced sonography is very useful in the evaluation of response to ablation therapy of hepatocellular carcinoma.

[Inflammatory bowel disease--diagnosis and therapy]

The first intention in the management of patients with inflammatory bowel disease (IBD) is the improvement of quality of life. It is important to avoid unnecessary investigations and to protect the patients from therapeutic approaches, which efficacy is not proven. The following remarks are based on the guidelines of The German Society of Gastroenterology for diagnosis and therapy of ulcerative colitis and Crohn's disease, which include an accurate diagnosis, the treatment of the acute phase, the maintaining of remission and the management of complications. The therapy depends on the severity of the acute phase and on the localisation of the disease. Immunosuppressive therapy with azathioprine or mercaptopurine is indicated in patients with steroid-dependent or steroid-resistant disease.

[Phenprocoumon-induced liver failure]

HISTORY

A 61-year-old woman was referred because of painless jaundice, laboratory tests having indicated hepatitis with impaired liver functions. For the past two years she had been taking phenprocoumon because she had atrial fibrillation.

INVESTIGATIONS

Serological tests largely excluded infectious, autoimmune or metabolic etiology, so that the diagnosis of drug-induced hepatic disease was made. Liver biopsy showed necrotic liver cells and mild inflammatory reaction.

TREATMENT AND COURSE

A perforating duodenal ulcer required urgent surgical intervention, after which liver functions further deteriorated. The patient having refused liver transplantation she was treated symptomatically (oral vitamin K. lactulose, diuretics), phenprocoumon was discontinued and her condition slowly improved. She was discharged after two months. At subsequent examination she was symptom-free, the INR was 1.41, transaminases were normal and ultrasound merely showed a slightly inhomogeneous internal structure.

CONCLUSION

Phenprocoumon can cause liver damage even when the drug has been taken for prolonged periods without any problems. A careful history about previously administered drugs should be taken in any case of hepatitis of uncertain etiology.

[Imaging in gastroenterology--what is new?]

In the last years there are a lot of developments in endoscopical, radiological and sonographical imaging techniques for example virtual colonoscopy, capsule endoscopy and contrast-enhanced sonography. The MR- or CT-colonography has a high sensitivity of about 90% in the detection of polyps > 1 cm. But what there is to be said against virtual colonoscopy as a routine examination is the need for bowel cleansing with an oral lavage and the high costs due to a long examination and evaluation time. The capsule endoscopy is a very interesting new imaging technique for the diagnostic evaluation of small bowel diseases. The capsule endoscopy is superior to push-enteroscopy, the gold-standard until now. But it is not clear, whether there is change in therapeutical procedures due to the results of the capsule endoscopy and whether the high costs for the examination are justified. The contrast-enhanced sonography improves especially the detection and characterization of solid liver lesions and some CT- and MR-examination will be unnecessary in the future.

[Pantoprazole-induced hepatitis]

HISTORY

A 46-year-old woman presented for an emergency admission because of colic-like upper abdominal pain and markedly impaired general condition. Eight days before admission she had started and continued to take pantoprazole because of symptoms of gastroesophageal reflux.

INVESTIGATIONS

Clinical examination and laboratory tests indicated abnormal liver functions suggesting hepatitis. Serology largely excluded an infectious, autoimmunological or metabolic cause. Duplex sonography gave no evidence of bile obstruction or Budd-Chiari syndrome.

DIAGNOSIS AND COURSE

The patient's condition and laboratory tests after the drug had been discontinued gradually improved on symptomatic treatment, indicating pantoprazole-induced hepatitis.

CONCLUSION

Intake of proton pump inhibitors is a rare cause but should be considered in the differential diagnosis of hepatitis of uncertain etiology.

[Interventions in gastroenterology and hepatology: indications and results]

Interventional therapy and above all the endoscopic interventions have gained importance in the last years. There are a lot of interventional procedures with curative or palliative intention, which value have to be compared with surgical therapy as the therapeutical gold standard. Today the endoscopic hemostasis for ulcer or variceal bleeding are the therapy of choice with very good results. Thus the need for surgery is low. The treatment of benign esophageal stenosis is a domain of the endoscopic therapy. Dilatation with bougies or balloon dilatation get comparable results. In patients with achalasia age and comorbidity of the patients are of great importance for the choice of therapy. In young patients the botulinum toxin injection should be avoided because of a very low long-term efficiency and because surgery become more difficult after botulinum toxin injection. As colorectal cancer is a frequent tumor endoscopic polypectomy and mucosectomy are very important endoscopic procedures, because there is a possibility of cancer prevention and when risk factors are be considered a curative therapy of early colorectal cancer is possible.

[Colorectal carcinoma: screening--early detection]

Colorectal cancer is the second leading cancer disease in Germany. The mortality is still 60%. 75% of the patients have no risk factors for colorectal cancer, 18% have a positive family history for the disease. In these patients colorectal cancer arise from benign adenomatous polyps. A 76-90% reduction in colorectal cancer incidence can be achieved by endoscopic polypectomy. Tumor stage is an important determinant of outcome. In Dukes stage A the overall survival rate is over 90%. By annual fecal occult blood test the incidence and mortality rate of colorectal cancer can be reduced significantly. The combination of fecal occult blood test and flexible sigmoidoscopy seems to be more effective. An alternative strategy is a colonoscopy every ten years. But the important problem in Germany is the very low compliance of the patients. Only 16% of the men and 34% of the women are participating in cancer surveillance program.

[The patient with hematemesis. What to do?]

In patients with hematemesis an emergency endoscopy has to be done as soon as possible. In ulcer disease emergency endoscopic treatment is indicated in ulcers with active bleeding or with visible vessels in the base of the ulcer. There is no significant difference in the efficacy between the various endoscopic methods of hemostasis. Gold standard in the treatment of acute variceal bleeding is the hemostasis by endoscopic ligation or sclerotherapy. Because of the very low complication rate variceal ligation is the therapy of choice in the prevention of variceal rebleeding. Especially in patients with preexisting portal hypertensive gastropathy an additional therapy with beta-blocker is recommended. In the prevention of first variceal bleeding a combination therapy with beta-blocker and nitrate is indicated in patients with big varices with red colour signs and in patients with decompensated liver cirrhosis (Child B).

[The value of shockwave therapy in treatment of humero-radial epicondylitis]

Numerous therapies exist for the treatment of radial Epicondylitis. A new treatment, Extracorporal Shock-Wave Therapy (ESWT) has recently been proposed. Based on a review of the medical literature various mechanisms of action are presented. Except for the treatment of conditions of the urinary system, ESWT is controversial. Scientific proof of enhanced efficacy of ESWT compared to other treatments of radial Epicondylitis is still lacking. Prospective, randomized follow-up studies of large patient populations under standardized technical conditions are needed. Based on current knowledge, ESWT of radial Epicondylitis should only be applied if three conditions are fulfilled: 1) the diagnosis of radial Epicondylitis has been ascertained, 2) conservative therapies for at least one year failed, and 3) the only alternative is surgery.

All-optical sampling with a monolithically integrated Mach-Zehnder interferometer gate

An all-optical sampler consisting of a polarization-independent monolithic Mach-Zehnder interferometer with integrated semiconductor optical amplifiers and a temporal resolution of 1 ps is presented. As an example, a simple 320-Gbit/s pattern has been successfully sampled, demonstrating the functionality of this scheme for high-bit-rate waveform characterizations in light-wave systems.

Xenotransplantation of parathyroids in rats using barium-alginate and polyacrylic acid multilayer microcapsules

The integrity and function of encapsulated parathyroid tissue following xenotransplantation is limited by oxygen and nutrition supply and capsule fibrosis. Since some of these factors depend on stability and biocompatibility of the coating material, multilayer microcapsules have been developed. Parathyroid tissue pieces and digested single cells from pigs were encapsulated in barium-alginate and in polyacrylic acid (PAA) multilayer capsules. After 7 days of culture the function of the encapsulated cells were assessed. Subsequently, in a part of the cultured microcapsules the viability was directly assessed whereas the other part was transplanted in dark animal [DA] rats for 30 days. After explantation viability and fibrotic reaction were examined. Single cells showed a significant increase in parathyroid hormone [PTH] secretion when exposed to medium low in calcium, whereas minced tissue pieces revealed necrosis without stimulatory responsiveness. Morphometry showed significantly better viability of single cells compared with minced tissue in vitro and in vivo. The fibrotic reaction against capsules with minced tissue was more pronounced than for capsules containing single cells. There was no difference between barium alginate and PAA capsules when containing minced tissue. In single cells, however, the fibrous tissue reaction differed significantly between barium alginate and PAA capsules. Encapsulated single cells of parathyroid tissue maintain detectable function and viability. In contrast minced tissue underwent necrosis and induced significantly more connective tissue reaction than single cells indicating an interrelationship between necrosis and fibrosis.

Effect of media composition on long-term in vitro stability of barium alginate and polyacrylic acid multilayer microcapsules

For a number of applications stability of microcapsules is a critical factor. Since the maintenance of polyelectrolyte complexes depends considerably on the ion composition we tested the physical properties of barium alginate capsules and searched for conditions to improve stability by a multilayer coating with polyethylenimine (PEI) and polyacrylic acid (PAA). Mechanical stability and diameters were determined in barium alginate capsules and compared with multilayer capsules. Multilayer coating resulted in smaller capsules than barium complexing alone. The difference was more pronounced when CaCl2 was used instead of NaCl during coating. Barium alginate capsules and application of CaCl2 during coating led to continuous pressure profiles, whereas NaCl resulted in bursting at a defined pressure, indicating the additional contribution to mechanical stability by the outer layers. After 7 d culture, mechanical stability of coated capsules decreased in RPMI and NaCl but was most pronounced in sodium citrate. The capsule diameter increased in sodium citrate, less pronounced in NaCl and was significantly different to RPMI and double distilled water. During long-term culture in RPMI, the diameter increased and mechanical stability decreased significantly. Multilayer coating improved mechanical stability which was impeded most in sodium citrate, to a lesser extent by NaCl and RPMI even after long-term exposure.

[Abdominal ultrasound diagnosis]

The doppler sonography is an important tool in the diagnosis of liver diseases, even by using new techniques like the power doppler. There are a lot of indications for the evaluation of the hepatic vessels. Apart from the diagnosis of portal hypertension in liver cirrhosis a portal vein thrombosis should be detected or excluded in cases of new or refractory ascites. The Budd-Chiari syndrome is another important indication. Focal liver lesions can have characteristic findings in doppler sonography, but an exact differentiation of liver tumors is not possible. But doppler sonography even using the power doppler technique is be used more and more in hepatocellular carcinoma to evaluate the response to treatment with chemoembolization, radiofrequency thermoablation or percutaneous ethanol injection. The accuracy is compatible to angiography and computer-tomography.

The effect of vanadium-contaminated commercially available albumin solutions on renal tubular function

We report our findings in a patient with coronary heart disease who received an intravenous albumin solution that contained a significant level of vanadium on the first day after elective primary coronary revascularization. Six patients who underwent similar surgical procedures without albumin infusion were taken as a control group. After administration of the V-contaminated albumin solution, the urinary excretion rates of alpha-glutathione S-transferase, a marker of proximal tubular damage, showed a several-fold elevation above the reference value, and the mean excretion rate was significantly different from that of the control group (p < 0.05). pi-Glutathione S-transferase, a marker of distal tubular damage, only marginally exceeded the upper reference limit in two urine samples from this patient. In all urine samples from the control group the excretion rates of pi-GST were below the detection limit. No significant differences in the excretion rates of alpha1-microglobulin and N-acetyl-beta-D-glucosaminidase were found between the patient treated with the albumin infusion and the patients of the control group. The biological half-life of intravenously administered V was approximately 125 h. All commercially available albumin solutions contain traces of vanadium with the concentration varying between 1.1 and 677 microg/l. The free V fraction in the albumin solutions increased with total V concentration, the highest concentration of free V found being 299 microg/l. The data suggest that the use of albumin solutions containing high levels of vanadium can lead to renal injuries, especially in patients with existing impaired renal function, as is the case with extracorporal circulation. The contamination is believed to be a result of the commercial isolation process.

Cleavage of the fifth component of complement and generation of a functionally active C5b6-like complex by human leukocyte elastase

Activation by complement C3/C5 convertases of the fifth component of human complement, C5, leads to two active cleavage products: C5a, a chemotactic peptide, and C5b, the activated form of C5. Human leukocyte elastase (HLE) has long been known to also release from C5 a chemotactic, C5a-like fragment. This, however, cannot be identical with C5a, since HLE does not cleave peptide bonds at the carboxyl group of arginine, the cleavage site that separates C5a and C5b after the exposure to the complement convertases. Therefore, the question arose whether HLE is capable of releasing a functionally C5b-like product from C5. The results show that this is, indeed, so. Treatment of human C5 with HLE in the presence of C6 leads to the formation on an active C5b6-like complex that lyses non-sensitized guinea pig red cells upon addition of the terminal components C7, C8, and C9. However, since C6 is highly sensitive to the hydrolytic action of HLE, the yield of the activation complex is rather low. The results offer a third possibility for the activation of C5: 1) classical cleavage at Arg74 by complement convertases, 2) oxidation of methionine residues without cleavage, and, as shown here, 3) cleavage by elastase at (a) site(s) distal from Arg74. The three procedures may modulate the relative yield of the two activities generated from C5, C5a-like and C5b-like effects.

Vanadium-contaminated perioperatively administered infusion solutions and drugs

Vanadium was determined in 51 solutions and drugs for intravenous administration and in 6 salt components of a multitrace element solution using electrothermal atomic absorption spectrometry. The highest V contaminations were found in albumin solutions showing values of more than 600 microg/L V. Two heparines contained 14.3 and 122 microg/L V, respectively. In the ultratrace element solution, 14.8 microg/L vanadium were determined. The most contaminated salt of this solution was Mn(II)-DL-aspartate (12.8 microg V/g). The concentrations of unbound V (Vf) in the albumin solutions were between 0.31 and 299 microg/L. The manufacturing process is the reason for V contamination. The biological half-life of V administered intravenously by albumin solutions in man was about 125 h.

Discontinuous electrokinetic chromatography of parabens using different substituted resonances as pseudostationary phases

Resorcarene derivatives, negatively charged even at moderate pH, were synthesized and employed as pseudostationary phases to achieve mobilities exceeding that of the electroosmotic flow. Under these conditions, a discontinuous electrolyte system was developed which allows the separation of four uncharged homologous 4-hydroxybenzoic esters (parabens) within a zone of resorcarene electrolyte, and the detection of these UV active compounds in a resorcarene-free zone, free from the high UV background absorbance of the resorcarenes. Resorcarenes, with differently charged functionalities (carboxylate and phosphate groups) to provide the electrophoretic mobility and with alkyl residues of different chain lengths responsible for the chromatographic interactions with the analytes, were tested and compared in terms of mobility and selectivity. Only the resorcarene phosphates exhibited sufficient mobilities at low pH exceeding the mobility of the electroosmotic flow (EOF). Retention factors of the parabens were found to increase with increasing chain length of the alkyl residues attached to the resorcarene. However, maximum selectivity was observed for an intermediate chain length (C8). An equation for the calculation of retention factors in discontinuous electrokinetic chromatography (EKC) is presented.

[Total quality management in laboratory medicine]

The German Public Health will be continuously challenged in the future. It has to be assumed that modified managed care will not only take place sporadically. Thus, quality aspects of services gain more and more significance. Only suppliers will be successful who can offer services of highest quality at lowest prices. Quality in a comprehensive sense has to be substantiated in the near future. It is recommended to apply industry proven models also in public health service. Medical laboratories can be pioneers in this field as they have been already in the past. All previously proposed procedures can not describe quality of results comprehensively. They are based to a high degree on external control. Total quality management, however, represents a comprehensive approach. Principles are zero-defect approach, customer orientation and system management. Quality is given in the sense of TQM if the customer is permanently satisfied with the service of the supplier. In such a way, the customer defines quality of service. A customer is everyone who receives products or services. TQM overcomes the drawbacks of quality management systems, which are strongly formal and oriented by external control, as accreditation (EN 45,000) or certification (ISO 9000). Competition between hospitals is a declared goal of German health politics because usually quality is increased and cost decreased as a consequence. Competition means also comparison of services. TQM emphasizes benchmarking especially among the best suppliers.

[Pancreaticolithiasis and pancreatic pseudocysts--interventional therapy]

Interventional (non-surgical) therapy is a relative new approach in the management of chronic pancreatitis. Indications for endoscopic therapy are pseudocysts and strictures or stones of the main pancreatic duct. Endoscopic sphincterotomy, extraction of pancreatic duct stones, extracorporal shock-wave lithotripsy (ESWL), pancreatic duct stenting and drainage of pseudocysts are all methods with a high success rate but with a low complication rate. Therefore in patients with chronic pancreatitis and with a failure of conservative management interventional techniques have to be considered. They may be an alternative to surgical procedures.

Effect of programmed endoscopic follow-up examinations on the rebleeding rate of gastric or duodenal peptic ulcers treated by injection therapy: a prospective, randomized controlled trial

BACKGROUND AND STUDY AIMS

A second-look endoscopy is often performed to evaluate the efficacy of a prior injection therapy in patients with bleeding peptic gastric or duodenal ulcers. Although this strategy is widely established, it does not rely on unequivocal data from controlled studies. In a prospective, randomized, controlled multicenter trial we assessed the effect of programmed endoscopic follow-up examinations with eventual retreatment on the outcome of bleeding ulcers in these patients.

PATIENTS AND METHODS

One hundred and five patients with gastric or duodenal peptic ulcers presenting with active (Forrest type I) or recent (Forrest type IIa and IIb) bleeding upon endoscopy within four hours after admission were included in the study. Emergency treatment consisted of the sequential injection of both epinephrine (1:10,000 v/v) and up to 2 ml of fibrin/thrombin around the ulcer base. Fifty-two patients were randomized to receive programmed endoscopic monitoring with eventual retreatment in cases of Forrest type I, IIa, or IIb ulcers beginning within 16-24 hours after the index bleed. Follow-up endoscopies were continued until the macroscopic appearance revealed a Forrest type IIc or III ulcer. Fifty-three patients in the control group were closely monitored, and only received a second endoscopy when there was clinical or biochemical evidence of recurrent bleeding. The groups did not differ with respect to age, sex, site and severity of bleeding.

RESULTS

The numbers of patients with recurrent bleeding were similar whether they were endoscopically monitored or not (21% versus 17%, P=0.80 chi-squared test). In addition, there was no statistically significant difference between the two groups with respect to the number of blood units transfused, need for surgical intervention, hospital stay or number of deaths (Mann-Whitney U-test). Improving local ulcer stigmata was not related to a better outcome.

CONCLUSIONS

Programmed endoscopic follow-up examinations with eventual retreatment in patients locally injected for an acute or recent hemorrhage from a gastric or duodenal ulcer did not influence their outcome when compared to patients receiving only a second endoscopic intervention upon evidence for recurrent hemorrhage. Scheduled control endoscopies cannot be recommended after an initial successful endoscopic treatment of peptic ulcer bleeding when selection of the patients for second-look endoscopy is directed by the Forrest criteria.

Interleukins and their antagonists but not TNF and its receptors are released in post-ERP pancreatitis

OBJECTIVE

Usually it is not possible to study the initial systemic response in patients with acute pancreatitis in the first hours after onset of the disease. We used postendoscopic retrograde pancreatography (ERP) pancreatitis as a model to study cytokine and anticytokine release in the early phase of human acute pancreatitis.

METHODS

Post-ERP pancreatitis was defined as a threefold increase in serum amylase and at least two of the following clinical symptoms: abdominal pain, nausea, vomiting or peritonism 24 h after ERP. Serum levels of pro-inflammatory cytokines interleukin-1beta (IL-1beta), interleukin-6 (IL-6), interleukin-8 (IL-8), tumour necrosis factor alpha (TNF), as well as endogenous antagonistic mediators of the systemic inflammatory response such as soluble tumour necrosis factor alpha receptors p55 (TNFR p55) and p75 (TNFR p75), and IL-1-receptor antagonist (IL-1-RA) and interleukin-2-receptor (IL-2R) as indicators of lymphocyte activation were measured before and 0, 1, 4, 12, 24 and 48 h after ERP. In nine patients with acute post-ERP pancreatitis, these parameters were monitored daily until C-reactive protein (CRP) was within normal ranges and were compared to patients without pancreatitis after ERP.

RESULTS

IL-1beta was not detectable in five patients with and four patients without post-ERP pancreatitis. The values of the remaining patients in both groups were lower than 3.9 pg/ml. IL-8 and IL-1-RA serum concentrations peaked 12 h after ERP (132.9 and 3245.0 pg/ml respectively) compared to patients without post-ERP pancreatitis (25.8 and 389.9 pg/ml respectively). The IL-6 concentration increased to 81.6 pg/ml (8.0 pg/ml in control patients) 24 h after ERP, while the peak values for CRP were measured 72 h after ERP (164.0 versus 7.7 mg/l). IL-2R content was maximally elevated 144 h after ERP (688.8 versus 255.9 U/ml), while concentrations of TNF and its receptors showed no significant change over time.

CONCLUSION

The initial response of the cytokine network to damage of the human pancreas leading to acute pancreatitis includes the release of IL-8 and the IL-1 antagonist IL-1-RA, while IL-1beta is not found in the systemic circulation. The TNF system does not seem to be involved as indicated by the lack of detectable changes in TNF and the soluble TNFR p55 and p75 serum concentrations. Lymphocyte activation as indicated by elevated IL-2R levels occurred days after the initial trauma. Even mild post-ERP pancreatitis leads to significant systemic release of cytokines and their biological counterparts.

Post-ERP pancreatitis as a model for cytokine induced acute phase response in acute pancreatitis

BACKGROUND/AIMS

By contrast with animal models, in most cases it is not possible to examine the systemic response in patients in the first hours after onset of acute pancreatitis. The aim was to determine whether endoscopic retrograde cholangiopancreaticography (ERP)-induced pancreatitis can be used as a human model for the study of cytokine release and acute phase response in the first hours of the disease.

PATIENTS AND METHODS

Seventy consecutive patients undergoing ERP for different reasons were prospectively evaluated by sampling blood before and 0, 1, 4, 12, 24, and 48 hours after ERP and, in patients who developed an acute post-ERP pancreatitis, daily until C reactive protein (CRP) was within normal range. A post-ERP pancreatitis was defined as a three-fold increase of amylase or lipase and at least two of the clinical symptoms: abdominal pain, nausea, vomiting, and peritonism during 24 hours after ERP.

RESULTS

Nine out of 70 patients developed an acute pancreatitis. Cytokines and other biochemical variables were measured in those nine and in 34 patients out of the 61 not developing pancreatitis. In the nine patients amylase and lipase increased within the first hour after ERP with maximum values between four and 12 hours. Interleukin-6 increased to maximal concentrations after 24-48 hours and the highest CRP concentrations were found 72 hours after ERP. Tumour necrosis factor did not change.

CONCLUSION

Post-ERP pancreatitis is an ideal model in which to examine the initial cytokine and acute phase response in the first hours after the initiation of the disease.

Quantification of vanadium in serum by electrothermal atomic absorption spectrometry

We describe an ultrasensitive and reliable method for determining vanadium in human serum by electrothermal atomic absorption spectrometry. After lyophilization, the serum is digested in acid at high pressure, and the digests are evaporated to a small volume. Vanadium in the digests is complexed with cupferron, extracted, and dried. The residue is redissolved in formic acid, where it is 15-fold more concentrated than in the original serum sample. To enhance the furnace sensitivity, we injected six 40-microL aliquots (total, 240 microL) of the concentrated extract. The median concentration of vanadium in 108 persons was 50 ng/L, in good agreement with previously reported results by neutron activation analysis. The characteristic mass obtained (the mass required to give a signal of 0.0044A. s) was 28 pg, the limit of detection 11 ng/L, the limit of quantification 17 ng/L, and the total imprecision (CV) 5.5% at 1.54 micrograms/L. In two assays of Standard Reference Material 1577a (certified vanadium content 99 +/- 8 ng/g), we obtained values of 94.1 and 97 ng/g.

Quantification of vanadium in serum by electrothermal atomic absorption spectrometry

We describe an ultrasensitive and reliable method for determining vanadium in human serum by electrothermal atomic absorption spectrometry. After lyophilization, the serum is digested in acid at high pressure, and the digests are evaporated to a small volume. Vanadium in the digests is complexed with cupferron, extracted, and dried. The residue is redissolved in formic acid, where it is 15-fold more concentrated than in the original serum sample. To enhance the furnace sensitivity, we injected six 40-microL aliquots (total, 240 microL) of the concentrated extract. The median concentration of vanadium in 108 persons was 50 ng/L, in good agreement with previously reported results by neutron activation analysis. The characteristic mass obtained (the mass required to give a signal of 0.0044A. s) was 28 pg, the limit of detection 11 ng/L, the limit of quantification 17 ng/L, and the total imprecision (CV) 5.5% at 1.54 micrograms/L. In two assays of Standard Reference Material 1577a (certified vanadium content 99 +/- 8 ng/g), we obtained values of 94.1 and 97 ng/g.

Complement activation by myeloperoxidase products released from stimulated human polymorphonuclear leukocytes

Purified human myeloperoxidase (MPO) converted human C5 to an activated form, i.e. the C5 protein adopted a configuration expressing a binding site for C6; the resulting C56 complex then reacted with C7, C8 and C9 forming a hemolytic C5-9 complex. For the activation by myeloperoxidase chloride and hydrogen peroxide were essential. This indicates that the peroxidase acted through the generation of HOCl which had been shown earlier to oxidize and activate C5. Human polymorphonuclear leukocytes (PMN) were stimulated in vitro by incubation with opsonized zymosan; thereafter the supernatants were tested for C5 activating potency. Stimulated PMN release H2O2 and MPO that produces hypochlorite and secondarily various chloramines. As a trap for the labile hypochlorite generated excess taurine was added to the PMN suspensions during the incubation. Hypochlorite is then stoichiometrically converted to the relatively stable taurine chloramine. In order to rule out interfering activities of proteolytic enzymes released from the PMN and known to attack C5, the supernatants were ultracentrifuged, and the ultrafiltrates, containing only low molecular weight compounds, were used for the further studies. They contained taurine chloramine, estimated photometrically, and they activated C5 upon incubation, assayed functionally by reactive lysis. Azide, an inhibitor of myeloperoxidase, and catalase which destroys H2O2, essential for MPO-catalyzed oxidations, prevented the generation of C5 activating potency and of chloramines. Unstimulated PMN produced neither oxidants nor C5 activating potency. When taurine was omitted from the PMN suspensions during stimulations much less oxidant was found in the supernatants and less C5 activating potency. These findings indicate that the C5 activating agent was produced by stimulated PMN through MPO-generated hypochlorite, trapped as taurine chloramine. In the absence of added taurine the hypochlorite formed by MPO oxidized endogenous amines that also activated C5. Further studies suggested that among these was some monochloramine derived from endogenous ammonia. Activation of the terminal complement reaction sequence by MPO released from stimulated PMN may represent a third pathway to complement activation contributing to and reinforcing complement and PMN functions at the site of inflammation or tissue injury.

Multicentre evaluation of an immunological rapid test for the detection of troponin T in whole blood samples

In a multicentre study we assessed the analytical and diagnostic performance of a rapid test (TROPT rapid test, Boehringer Mannheim; in the USA: CARDIACT) for cardiac troponin T compared to quantitative troponin T ELISA and creatine kinase-MB mass determinations. The rapid test requires 150 microliters of heparinized or EDTA whole blood; serum is not suitable. Interference testing with biotin, haemoglobin and 27 standard drugs yielded no significant influence in the physiological range. Skeletal muscle troponin T concentrations > or = 40 micrograms/l gave positive results with the rapid test. We used the rapid test for 369 samples from 203 patients with suspected acute coronary syndromes and compared the results to troponin T ELISA and creatine kinase-MB mass. 90 patients (44%) were primarily classified as having myocardial infarction by the WHO criteria. Twenty-two (20%) of the 113 non-myocardial infarction patients were unstable angina pectoris cases showing increased troponin T ELISA but not increased creatine kinase-MB mass values. Consequently, these were classified as minor myocardial damage cases. The rapid test was positive in 99% of all samples with a troponin T ELISA value > or = 0.30 micrograms/l and negative in 95 to 96% of all samples below this value. Diagnostic sensitivities for the detection of acute myocardial infarction within the first 12 hours after onset of pain were the same, 90%, for the rapid test, troponin T ELISA and creatine kinase-MB mass. After 48 hours, diagnostic sensitivity of creatine kinase-MB mass sharply decreased whereas that of the troponin T assays remained close to 100% beyond 72 hours after onset of symptoms. Diagnostic specificities for acute myocardial infarction (WHO) of all markers remained between 80 and 100% over this time. The diagnostic sensitivity of the rapid test for the detection of high risk unstable angina pectoris patients with minor myocardial damage was nearly the same as for troponin T ELISA. A major advantage of the rapid test is the ease of use and 20 minute turn around time. This facilitates the detection of increased troponin T at alternate sites.

[CT-guided percutaneous endoscopic gastrostomy: a successful method if transillumination is not possible]

BACKGROUND AND OBJECTIVE

If transillumination is not possible, percutaneous endoscopic gastrostomy (PEG) is contraindicated. In these cases the stomach had so far to be punctured directly during radiological monitoring. A new method is described which combines endoscopy and computed tomography (CT) for performing a percutaneous endoscopic gastrostomy.

PATIENTS AND METHODS

Among 189 patients who were to have the procedure there were eleven (nine men, two women) in whom transillumination was not possible. After endoscopic insufflation of air PEG was done under CT guidance, using the common pull-through technique.

RESULTS

The combined method was successful in ten of the eleven patients without complication. In one patient with hepatomegaly and interposition of the transverse colon PEG was not possible even with CT guidance.

CONCLUSIONS

The combined endoscopic-radiological method is practicable and safe in cases in which transillumination is not possible. There are several advantages compared with direct puncturing: The common pull-through technique can be used; radiological exposure is low and other clinically relevant findings may be revealed by the endoscopy.