Comparative safety of dipeptidyl peptidase-4 inhibitors and sulfonylureas among frail older adults

BACKGROUND

Studies comparing dipeptidyl peptidase-4 inhibitors (DPP4Is) to sulfonylureas (SUs) are unavailable for frail older adults, especially nursing home (NH) residents. We examined the effects of DPP4Is versus SUs on severe adverse glycemic events, cardiovascular events, and death among NH residents.

METHODS

We conducted a national retrospective cohort study of long-stay NH residents aged ≥65 years using 2008-2010 national US Minimum Data Set clinical assessment data and linked Medicare claims. Exposure was new DPP4I versus new SU use assessed via Medicare Part D drug claims. One-year outcomes were severe hypoglycemia, severe hyperglycemia, acute myocardial infarction (AMI), heart failure (HF), major adverse cardiovascular events plus HF (MACE+HF), and death. We compared outcomes after propensity score matching using Cox proportional hazards regression models.

RESULTS

The cohort (N = 2016) had a mean (SD) age of 81 (8.1) years and was 72% female. Compared with SU users, DPP4I users had a lower 1-year rate of severe hypoglycemic events (HR = 0.57, 95% CI 0.34-0.94), but statistically similar rates of severe hyperglycemic events (HR = 0.94, 95% CI 0.52-1.72), AMI (HR = 0.76, 95% CI 0.44-1.30), HF (HR = 1.01, 95% CI 0.79-1.30), MACE+HF (HR = 0.90, 95% CI 0.72-1.12), and death (HR = 0.97, 95% CI 0.86-1.10).

CONCLUSIONS

DPP4Is should be a preferred treatment option over SUs for NH residents and other frail older adults given the importance of avoiding hypoglycemia.

A circovirus-like infection in geese related to a runting syndrome

Diagnostic investigations in a large commercial flock of geese with a history of increased losses and runting, lead to the negative contrast electron microscopic detection of circovirus-like viruses in the lymphoreticular tissue in eight of nine selected geese with growth retardation. With the exception of a mild cloudiness of some air sacs, macroscopic changes pointing to an infection were missed. Histopathological changes concentrated on the lymphoreticular tissue. Lymphocytic depletion and histiocytosis were most evident in the bursa of Fabricius. Basophilic globular inclusions were found in the cytoplasm of medullar and cortical bursal follicular cells, and bursal epithelial cells. Ultrastructural examination of these inclusions revealed paracrystalline or multilayered arrays, or randomly arranged complexes of isometric viral particles, about 14 nm in diameter. The pathological appearence of this, so far unknown, infection in geese shows numerous similarities to circovirus infection in pigeons. In the described flock of geese, a virus-induced immunosuppression could have been a predisposing factor for other infectious agents such as Riemerella anatipestifer or Aspergillus fumigatus, thus contributing to the increased losses and developmental disorders.

Cancer Incidence in Five Continents: Inclusion criteria, highlights from Volume X and the global status of cancer registration

Cancer Incidence in Five Continents (CI5), a longstanding collaboration between the International Agency for Research on Cancer and the International Association of Cancer Registries, serves as a unique source of cancer incidence data from high-quality population-based cancer registries around the world. The recent publication of Volume X comprises cancer incidence data from 290 registries covering 424 populations in 68 countries for the registration period 2003-2007. In this article, we assess the status of population-based cancer registries worldwide, describe the techniques used in CI5 to evaluate their quality and highlight the notable variation in the incidence rates of selected cancers contained within Volume X of CI5. We also discuss the Global Initiative for Cancer Registry Development as an international partnership that aims to reduce the disparities in availability of cancer incidence data for cancer control action, particularly in economically transitioning countries, already experiencing a rapid rise in the number of cancer patients annually.

Phenotypic characteristics of Riemerella anatipestifer and similar micro-organisms from various hosts

A total of 199 Riemerella anatipestifer (RA) and RA-like field strains isolated culturally from birds of 12 different species and from pigs were characterized using classical phenotypic and chemotaxonomic tests. The RA reference strain ATCC 11845 was included in the study. On the basis of the classical phenotypic characteristics studied and the numerical analysis of the whole-cell fatty acid patterns, the RA reference strain and 123 field isolates were assigned to the indole negative (IN) variant and 10 isolates to the indole positive (IP) variant of the species RA. The IN strains were isolated not only from poultry and free-living wild ducks, but also from pigs, guillemots and from a budgerigar and a herring gull. All the IP isolates were isolated from domestic ducks. One field strain from a chicken and one from a black-headed gull, which were distinguished from RA mainly by the negative a-glucosidase reaction and production of yellow pigment respectively, showed fatty acid methyl ester profiles chemotaxometrically different from those of RA. Another 64 field strains isolated from domesticated ducks, geese and muscovy ducks with signs and lesions very similar to those caused by RA were phenotypically and chemotaxometrically clearly different from RA and could not be classified to any of the known species. This possible bacterial pathogen is therefore given the preliminary designation of Riemerella-like (RA-L) taxon 1502.

[Substance abuse in recreational exercise]

Substance abuse has become increasingly widespread among athletes at sub competitive and recreational level, due in part to the lack of controls in form of doping tests. Hypertension and the many other side effects related to the illicit use of prescription drugs pose a substantial but often underestimated threat to public health. The symptoms are recognized late and are then mostly repressed or misjudged. Since the abuse is concealed to the doctor when help is finally sought, it results in extensive and expensive tests that can seldom lead to an effective treatment. Two case reports are presented to elaborate on this issue.

Dramatic increase in bilirubin after ERCP - pethidine as a possible cause of drug-induced hepatitis

We report on a 68-year-old female patient who was admitted with abdominal pain. Elevated lipase and CRP caused us to suspect pancreatitis. Because an enlarged pancreas head was found on ultrasound, an endoscopic retrograde cholangio- and pancreaticography was performed with a pethidine-containing premedication. Thereafter, bilirubin, gamma-glutamyl transpeptidase and alkaline phosphatase increased dramatically. There was also a moderate elevation of aspartate aminotransferase and alanine aminotransferase. A second endoscopic retrograde cholangio- and pancreaticography with the same premedication was performed in order to exclude an undetected concretion. This led to a further increase of bilirubin. An association with the drugs given as premedication was therefore suspected, and in fact, a hypersensitivity reaction towards pethidine was confirmed by the lymphocyte transformation test. We thus conclude that pethidine caused an immunologically mediated hepatic injury.

DNA excited-state dynamics: ultrafast internal conversion and vibrational cooling in a series of nucleosides

To better understand DNA photodamage, several nucleosides were studied by femtosecond transient absorption spectroscopy. A 263-nm, 150-fs ultraviolet pump pulse excited each nucleoside in aqueous solution, and the subsequent dynamics were followed by transient absorption of a femtosecond continuum pulse at wavelengths between 270 and 700 nm. A transient absorption band with maximum amplitude near 600 nm was detected in protonated guanosine at pH 2. This band decayed in 191 +/- 4 ps in excellent agreement with the known fluorescence lifetime, indicating that it arises from absorption by the lowest excited singlet state. Excited state absorption for guanosine and the other nucleosides at pH 7 was observed in the same spectral region, but decayed on a subpicosecond time scale by internal conversion to the electronic ground state. The cross section for excited state absorption is very weak for all nucleosides studied, making some amount of two-photon ionization of the solvent unavoidable. The excited state lifetimes of Ado, Guo, Cyd, and Thd were determined to be 290, 460, 720, and 540 fs, respectively (uncertainties are +/-40 fs). The decay times are shorter for the purines than for the pyrimidine bases, consistent with their lower propensity for photochemical damage. Following internal conversion, vibrationally highly excited ground state molecules were detected in experiments on Ado and Cyd by hot ground state absorption at ultraviolet wavelengths. The decays are assigned to intermolecular vibrational energy transfer to the solvent. The longest time constant observed for Ado is approximately 2 ps, and we propose that solute-solvent H-bonds are responsible for this fast rate of vibrational cooling. The results show for the first time that excited singlet state dynamics of the DNA bases can be directly studied at room temperature. Like sunscreens that function by light absorption, the bases rapidly convert dangerous electronic energy into heat, and this property is likely to have played a critical role in life's early evolution on earth.

Ecarin clotting time but not aPTT correlates with PEG-hirudin plasma activity

BACKGROUND

Novel antithrombotic agents such as hirudin have shown promise in the therapy of acute coronary syndromes. PEG-hirudin (polyethyleneglycol conjugated hirudin) has been developed to provide a longer plasma half-life and more stable antithrombotic plasma levels. Privious trials indicated a narrow therapeutic window for hirudin and a number of aPTT (activated partial thromboplastin time)-monitored trials investigating hirudin in acute coronary syndromes had to be stopped because of intracranial bleeding complications.

OBJECTIVES

The present study evaluates the ecarin clotting time (ECT), a parameter based on the conversion of prothrombin by the snake venom enzyme ecarin, for the monitoring of PEG-hirudin therapy.

METHODS

Plasma from either healthy volunteers (n=20) or from patients (n=10) suffering from unstable angina pectoris (UAP) was spiked with increasing PEG-hirudin concentrations. In a prospective randomized clinical trial patients with UAP were treated with intravenous PEG-hirudin or heparin over 72 hours. Patients were randomized to the following treatment groups: (1) heparin control group, n=15; (2) PEG-hirudin low dose (0.1 mg/kg bolus, 0.01 mg/kg/h infusion), n=19; (3) intermediate dose (0.15 mg/kg and 0.015 mg/kg/h), n=17; 4) high-dose (0.2 mg/kg and 0.02 mg/kg/h), n=16. Spiked plasma samples and plasma from UAP patients treated with i.v. PEG-hirudin were analyzed for aPTT, ECT, and PEG-hirudin levels.

RESULTS

A linear correlation up to the highest therapeutic concentrations could be observed between PEG-hirudin plasma concentrations and the ECT. This was true for both plasma samples spiked with PEG-hirudin in vitro as well as for samples taken from patients treated with i.v. PEG-hirudin (correlation coefficient 0.9, respect.) In contrast the aPTT did not show a reliable linear correlation to PEG-hirudin concentrations.

CONCLUSION

Monitoring of PEG-hirudin therapy by ECT may help to avoid inadequate anticoagulation or overdosing. Thus, the safety and efficacy profile of PEG-hirudin therapy is likely to be enhanced by ECT monitoring.

[A rare cause of malignant ascites--peritoneal mesothelioma]

HISTORY AND CLINICAL FINDINGS

A 56-year-old patient (case 1) with recurrent haemorrhagic ascites for one year was admitted to our hospital for further investigation. Besides massive ascites he did not show abnormal physical signs. In addition, two 45-year-old patients were admitted (case 2 and 3) with clinical signs of acute abdomen--one having muscular guarding in the epigastric angle, the other in the right lower quadrant. All 3 patients did not have serious illnesses in the past; the first 2 patients had occupational asbestos exposure.

INVESTIGATIONS

In patient 1 the ultrasound did not reveal abnormal findings besides ascites. Patients 2 and 3 underwent explorative laparotomy.

DIAGNOSIS, TREATMENT AND COURSE

In the first case a diagnostic laparoscopy revealed diffuse tumor proliferations with nodular formations over the entire peritoneum--histologically a malignant peritoneal mesothelioma of the epithelial subtype. Patient 2 showed intraoperatively metastatic spread of tumour formations with infiltration of the peritoneum and transverse mesocolon. The histologic finding was similar to that in the first case. Patient 3 had a perforated sigma diverticulitis which was treated by resection of the sigmoid. Incidentally a well differentiated papillary peritoneal mesothelioma was found in the resected specimen. The first two patients were treated with alpha-interferon subcutaneously resulting in a decrease of ascites production. Because patient 3 showed neither ascites nor evidence for malignancy no interferon was administered.

CONCLUSION

In case of haemorrhagic ascites of unknown cause a histological clarification by either laparoscopy or laparotomy is mandatory. Immunomodulation with interferon may be a promising approach.

A systematic approach to vaccine complexity using an automaton model of the cellular and humoral immune system. I. Viral characteristics and polarized responses

A modern approach to vaccination faces the compound complexity of microorganism behavior and immune response triggering and regulation. Since computational modeling can yield useful guidelines for biological experimentation, we have used IMMSIM(3), a cellular automaton model for simulating humoral- and cell-mediated responses, to explore a wide range of virus-host relations. Sixty-four virtual viruses were generated by an assortment of speed of growth, infectivity level and lethal load. The outcome of the infections, as influenced by the immune response and the bolstering of cures, obtained by vaccine presensitization are illustrated in this first article. The results of the in machina experiments allow us to relate the success rate of responses to certain combinations of viral parameters and by freezing one or the other branch, and to determine that some viruses are more susceptible to humoral, and others to cellular responses, depending either on single parameters or combinations thereof. This finding allows prediction of which infection may be susceptible to polarized ((Th)(1)>Th(2) and Th(1)<Th(2)) responses and will eventually help designing vaccines whose action relies on antagonizing both the specificity and the behavior of the invader. A second, not lesser, result of this study is the finding that humoral and cellular responses, while cooperating, towards the cure of the infected body, also show significant patterns of competition and mutual thwarting.

Flow cytometric monitoring of glycoprotein IIb/IIIa blockade and platelet function in patients with acute myocardial infarction receiving reteplase, abciximab, and ticlopidine: continuous platelet inhibition by the combination of abciximab and ticlopidine

BACKGROUND

Improvement of thrombolysis may be achieved by concomitant strong platelet inhibition. To monitor platelet function in patients with myocardial infarction (n=46) who were treated with the fibrinolytic agent reteplase, the glycoprotein (GP) IIb/IIIa blocker abciximab, and the ADP receptor antagonist ticlopidine, we developed a flow cytometric assay.

METHODS AND RESULTS

Binding of abciximab to platelets was directly monitored as the percentage of platelets stained by a goat anti-mouse antibody. Blood drawn 10 minutes and 2 hours after the start of therapy with reteplase and abciximab and during the 12-hour infusion of abciximab demonstrated a maximal blockade of GP IIb/IIIa (10 minutes, 86.2+/-10.3%; 12 hours, 85.8+/-7.1%). Starting at 24 hours, abciximab binding gradually decreased (24 hours, 74.6+/-16.2%; 48 hours, 66.8+/-14.9%; 72 hours, 60.5+/-16.7%; 96 hours, 49.4+/-17.8%; 120 hours, 35.8+/-16. 4%; and 144 hours, 29.9+/-15.3%). Binding of a chicken anti-fibrinogen antibody to platelets, indicating the level of functional blockade of GP IIb/IIIa, was inversely correlated with the binding of abciximab (r=-0.72, P:<0.0001). In blood drawn at 10 minutes, platelet aggregation was maximally inhibited but recovered within 48 hours even if the majority of GP IIb/IIIa receptors were still blocked by abciximab. Reteplase did not influence abciximab binding and did not activate platelets, as measured by P-selectin expression, fibrinogen binding, and platelet aggregation. Platelet inhibition that was achieved during the first 24 hours by abciximab was directly maintained by additional treatment with ticlopidine.

CONCLUSIONS

Flow cytometric monitoring of platelet function allows differentiation of the effects of reteplase, abciximab, and ticlopidine. The combination of abciximab and ticlopidine is an attractive therapeutic strategy that provides a fast and continuous platelet inhibition.

Long term response to gallstone treatment--problems and surprises

OBJECTIVE

To re-evaluate after 5 years the results of a randomised trial of cholecystectomy and lithotripsy for the treatment of symptomatic gallstones.

DESIGN

Late follow-up of a randomised controlled trial.

SETTING

Teaching hospital, UK.

SUBJECTS

144 of the 179 patients originally randomised.

INTERVENTIONS

Either elective open cholecystectomy under general anaesthesia or a maximum of 4 sessions of lithotripsy (up to 3000 shocks/session) on consecutive days with no anaesthesia or analgesia.

RESULTS

Of the original 87 patients randomised to be treated by lithotripsy, 39 (45%) subsequently underwent cholecystectomy, most of them within 32 months of treatment ("crossover" group). Patients in both main groups had a pronounced reduction in the number of episodes of pain at 5 years and significant reductions in the mean severity scores both on VAS and the McGill rating. Those in the crossover group had the worst scores. Gastrointestinal symptoms improved in the two main groups, but again the crossover group did least well. Quality of life improved significantly over baseline in the two main groups, but was much poorer in the crossover group.

CONCLUSIONS

Patients who had primary cholecystectomy were more likely to be free of pain than those treated by lithotripsy. Lithotripsy gave good symptomatic results in 55% of patients, and this was not dependent on clearance of stones. Patients who had a cholecystectomy after lithotripsy had the worst symptomatic results. It is difficult to identify patients who will not benefit from lithotripsy, but the presence of many coexisting symptoms may be an important predictor.

Ca2+ channels at the plasma membrane of stomatal guard cells are activated by hyperpolarization and abscisic acid

In stomatal guard cells of higher-plant leaves, abscisic acid (ABA) evokes increases in cytosolic free Ca(2+) concentration ([Ca(2+)](i)) by means of Ca(2+) entry from outside and release from intracellular stores. The mechanism(s) for Ca(2+) flux across the plasma membrane is poorly understood. Because [Ca(2+)](i) increases are voltage-sensitive, we suspected a Ca(2+) channel at the guard cell plasma membrane that activates on hyperpolarization and is regulated by ABA. We recorded single-channel currents across the Vicia guard cell plasma membrane using Ba(2+) as a charge-carrying ion. Both cell-attached and excised-patch measurements uncovered single-channel events with a maximum conductance of 12.8 +/- 0.4 pS and a high selectivity for Ba(2+) (and Ca(2+)) over K(+) and Cl(-). Unlike other Ca(2+) channels characterized to date, these channels rectified strongly toward negative voltages with an open probability (P(o)) that increased with [Ba(2+)] outside and decreased roughly 10-fold when [Ca(2+)](i) was raised from 200 nM to 2 microM. Adding 20 microM ABA increased P(o), initially by 63- to 260-fold; in both cell-attached and excised patches, it shifted the voltage sensitivity for channel activation, and evoked damped oscillations in P(o) with periods near 50 s. A similar, but delayed response was observed in 0.1 microM ABA. These results identify a Ca(2+)-selective channel that can account for Ca(2+) influx and increases in [Ca(2+)](i) triggered by voltage and ABA, and they imply a close physical coupling at the plasma membrane between ABA perception and Ca(2+) channel control.

[Obstructive jaundice caused by spontaneous rupture of an Echinococcus granulosus cyst into the bile duct system]

Obstructive jaundice caused by a parasitosis is very rare. It can be a complication of a cystic echinococcosis. We present the case of a 33-year-old man who suffered from cystic echinococcosis with an affection of the liver for several years. As a complication an echinococcal cyst had ruptured into the biliary tract and had led to an occlusion of the ductus hepatocholedochus. By means of ERCP the membrane of the echinococcal liver cyst was extracted in toto. Cholangioscopy followed and showed a free biliary tract without remaining cyst fragments. After these interventions the blood parameters normalized and the patient recovered. An additive chemotherapy with albendazole was started.

Platelet function during and after thrombolytic therapy for acute myocardial infarction with reteplase, alteplase, or streptokinase

BACKGROUND

Changes in platelet aggregation (PA) and platelet surface receptor expression induced by thrombolytic therapy for acute myocardial infarction may influence the rate of initial reperfusion and early reocclusion.

METHODS AND RESULTS

In the RAPID-1 (Reteplase Angiographic Phase II International Dose-finding study), RAPID-2 (Reteplase vs Alteplase Patency Investigation During myocardial infarction), INJECT (INternational Joint Efficacy Comparison of Thrombolytics), and GUSTO-3 (Global Use of Strategies To Open occluded coronary arteries) trials, 126 patients were enrolled in a single center. Patients were treated with either conventional alteplase (100 mg/180 min; n=15), accelerated alteplase (100 mg/90 min; n=21), reteplase 10+10-U double bolus (n=50), reteplase 10+5-U double bolus (n=15), reteplase 15-U single bolus (n=15), or streptokinase (1.5 MU/60 min; n=10). PA (after stimulation with ADP), P-selectin expression and fibrinogen binding to glycoprotein (GP) IIb/IIIa (determined by flow cytometry with and without stimulation with ADP), and levels of soluble P-selectin, prothrombin fragments F1 and F2, thrombin-antithrombin complexes (TAT), and antithrombin III (ATIII) were determined. PA decreased significantly at 1 and 2 hours in patients treated by 10+10-U reteplase or by streptokinase. Fibrinogen binding to platelet GP IIb/IIIa followed a similar pattern. Significant thrombin generation and significantly elevated thrombin levels during thrombolysis were reflected by increased F1 and F2 fragments and TAT levels in all treatment groups. ATIII levels decreased significantly during thrombolytic therapy.

CONCLUSIONS

A decrease in PA in patients treated by reteplase or streptokinase compared with alteplase could be observed in the early phase. Double bolus (10+10 U) reteplase and streptokinase resulted in lower PA at 1 and 2 hours than therapy with accelerated alteplase. Total fibrinogen and fibrinogen binding to GP IIb/IIIa tended to be lower during the first 2 hours after reteplase than after accelerated alteplase.

Pharmacokinetics and pharmacodynamics of lanoteplase (n-PA)

In acute myocardial infarction rapid, complete, and sustained reperfusion of the infarct-related coronary artery is the most important therapeutic principle. Lanoteplase or n-PA, a third-generation plasminogen activator consisting of a deletion and point mutant of tissue-type plasminogen activator (t-PA), is a promising agent to approach this therapeutic goal. The molecule exhibits an increased plasma half-life allowing single-bolus administration. In this article, after characterizing the n-PA molecule, the currently available pharmacokinetic and pharmacodynamic data including the results of the InTIME study are reviewed.

Platelet activation as a potential mechanism of GP IIb/IIIa inhibitor-induced thrombocytopenia

The blockade of the platelet integrin glycoprotein (GP) IIb/IIIa has proved to be an effective antiplatelet therapy. Profound thrombocytopenia has repeatedly been described as an adverse effect in patients treated with GP IIb/IIIa inhibitors, but its mechanism has not been elucidated yet. With use of flow cytometry, the activation status of platelets was monitored in 26 patients presenting with acute myocardial infarction who were treated with the GP IIb/IIIa inhibitor abciximab alone or in combination with the fibrinolytic agent reteplase. Fibrinogen and PAC-1 (a GP IIb/IIIa activation-specific monoclonal antibody) binding, as well as P-selectin expression on unstimulated platelets were constant in 25 patients throughout a follow-up of 7 days. In 1 patient (D.F.), the percentage of platelet-binding fibrinogen increased from 2.2% to 17.8%, for PAC-1 from 2.8% to 13.2%, and for P-selectin expression from 10.2% to 58.3% 10 minutes after the start of treatment. Furthermore, D.F. had a decrease in single platelet count in ethylenediaminetetraacetic acid-, citrate-, and heparin-anticoagulated and native blood. Blood films revealed platelet aggregates. In vitro testing of D.F.'s blood 2 and 4 weeks after initial admission demonstrated a reinduction of fibrinogen and PAC-1 binding to platelets, an increase of P-selectin expression, and formation of platelet aggregates following exposition of platelets to abciximab in vitro. In summary, this report describes the induction of platelet activation by a GP IIb/IIIa inhibitor in vivo and reinduction in vitro in direct association with thrombocytopenia. Platelet activation by GP IIb/IIIa inhibitors may be one potential mechanism for GP IIb/IIIa inhibitor-induced thrombocytopenia.

The role of endoscopic Doppler-sonography

Endoscopic Doppler sonography is a useful method that permits a differentiation to be made between high-risk lesions in danger of rebleeding and prognostically harmless ulcerations. Using this technique, vessels in the base of the ulcer can be reliably identified, and the indication for local endoscopic treatment established. The pulsed Doppler can be used to test the efficacy of prior endoscopic therapy within the framework of follow-up investigations; when arterial blood flow signals are found to persist, treatment needs to be repeated. With the aid of this "programmed" Doppler sonography-controlled endoscopic approach, which in some cases may be repeatable, the number of rebleeds, emergency operations, and probably also mortality, can be permanently lowered. Endoscopic Doppler sonography can also provide important additional information in the area of primary diagnosis and endoscopic treatment of esophageal and gastric varices. The Doppler exploration facilitates the assessment of the sclerosing effect, and is capable of identifying gastric varices and distinguishing these from other submucosal processes. For an assessment of the butyl cyanoacrylate varix, the Doppler is of particular value.

Intracellular localization and in vivo trafficking of p24A and p23

Recently, p24A and p23 (also termed Tmp21), two members of the p24 protein family, have been proposed to function as integral receptors for the COPI-vesicle coat. This study describes the intracellular localization and trafficking of p24A in comparison to p23. For immunolocalization of p24A and p23, strong reduction and denaturation conditions were necessary to allow antibody interaction. Both p24A and p23 cycle continuously between intermediate compartment (IC) elements and the cis-Golgi network. In vivo trafficking of p24A and p23 tagged to green fluorescent protein (GFP) revealed that both proteins travel by large (up to 1 micrometer in length) microtubule-dependent pre-Golgi carriers with a maximum speed of up to 1.6 micrometer s-1 from the IC to the Golgi cisternae. Aluminum fluoride, a general activator of heterotrimeric G-proteins, blocked peripheral pre-Golgi movements of GFP-p24A/p23 and inhibited fluorescence recovery after photobleaching in the perinuclear Golgi area. p24A and p23 are predominantly colocalized. Overexpression of GFP-p24A, to an extent which did not destroy the Golgi complex, induced delocalization of part of the proteins into ER elements. This study therefore gives new insights into the localization and trafficking behavior of the two COPI-binding proteins p24A and p23.

Augmented platelet aggregation as predictor of reocclusion after thrombolysis in acute myocardial infarction

RATIONALE

Reocclusion after thrombolysis diminishes the benefits of early reperfusion after acute myocardial infarction (AMI). No clinical or laboratory variables have been identified as predictors for reocclusion yet.

METHODS AND RESULTS

To evaluate hemostatic variables as potential risk determinants platelet aggregation (PA, representing platelet activity), thrombin/antithrombin complexes (TAT, representing thrombin generation), and plasminogen activator inhibitor type 1 (PAI-1, representing endogenous fibrinolysis) were determined in 31 patients with AMI at 0, 1, 2. and 12 h after the start of thrombolysis as well as at hospital discharge. Reocclusion (defined as reinfarction or angiographically confirmed, clinically silent coronary reocclusion) occurred in 5 patients within 5-14 days and in 8 patients within 1 year. TAT plasma concentrations were lower in patients with reocclusion than in those without (9.9+/-5.7 vs. 22.9+/-22.2 ng/ml at 2 h, 6.5+/-3.1 vs. 1 1.2+/-6.4 ng/ml at 12 h, means+/-SD, p <0.05 each). Neither concentration nor activity of PAI-1 in plasma differed between both patient groups. However, both slope and maximum of PA (induced by 2 micromol/l ADP) were augmented in patients with reocclusion (slope: 39.4+/-1.7 vs. 32.5+/-7.4 at 2 h, p <0.001; 42.6+/-2.6 vs. 36.6+/-8.9 at 12 h, p <0.01). Results were independent of the thrombolytic agent used (alteplase or reteplase). A PA slope at 2 h higher than the average slope before thrombolysis (37.2+/-5.7) could be identified as best predictor for early (within 5-14 d, p=0.017, sensitivity 1.00, specificity 0.69) and late reocclusion (within 1 y, p=0.009, 0.88 and 0.74, respectively).

CONCLUSIONS

Increased PA following coronary thrombolysis appears to be associated with early and late reocclusion. This marker could be useful in identifying patients who may benefit from more aggressive antiplatelet (such as GP IIb/IIIa receptor antagonists), interventional, or both strategies.

Induction of fibrinogen binding and platelet aggregation as a potential intrinsic property of various glycoprotein IIb/IIIa (alphaIIbbeta3) inhibitors

The blockade of platelet integrin glycoprotein (GP) IIb/IIIa is a promising new antiplatelet strategy. The binding of ligands or of the ligand-mimetic peptide RGD causes a conformational change of GP IIb/IIIa from the nonactivated to the activated state. Because several blocking agents/inhibitors are ligand-mimetics, the current study evaluates whether these agents have the intrinsic property to activate GP IIb/IIIa. Fibrinogen binding to GP IIb/IIIa on platelets or on CHO cells expressing recombinant GP IIb/IIIa was evaluated by flow cytometry or 125I-labeled fibrinogen. Incubation with the monoclonal antibody (MoAb) fragment c7E3 (abciximab) results in fibrinogen binding to GP IIb/IIIa and in the access of ligand-induced binding sites. At low concentrations (0.01 to 0.1 microgram/mL), this intrinsic activating property of c7E3 can result in platelet aggregation. The disintegrin flavorodin and the RGD analogue fradafiban also induce fibrinogen binding, whereas the blocking MoAbs 2G12 and P2 and the activation-specific MoAb PAC-1 do not. Aspirin and indomethacin cannot block c7E3-induced fibrinogen binding to GP IIb/IIIa, but can inhibit c7E3-induced platelet aggregation. Thus, we conclude that GP IIb/IIIa inhibitors can demonstrate an intrinsic activating property, which can result in fibrinogen binding to GP IIb/IIIa and consequently in platelet aggregation. Cyclooxygenase inhibitors can inhibit platelet aggregation caused by GP IIb/IIIa inhibitors. Further studies will have to evaluate the clinical relevance of the potential intrinsic activating property of GP IIb/IIIa inhibitors and define consequences for the future drug development and evaluation of these potent antiplatelet agents.

Cure with omeprazole plus amoxicillin versus long-term ranitidine therapy in Helicobacter pylori-associated peptic ulcer bleeding

BACKGROUND

Long-term prophylaxis with ranitidine reduces the risk of recurrent bleeding in patients with a history of bleeding peptic ulcers. To date, no randomized study has been performed to compare cure of Helicobacter pylori infection versus H2 blocker prophylaxis in patients with bleeding peptic ulcer.

METHODS

In a prospective randomized study, 95 consecutive patients with H. pylori-associated peptic ulcer bleeding were randomized to either ranitidine prophylaxis (150 mg at night) for 2 years or to H. pylori-eradication with omeprazole 60 mg twice daily plus amoxicillin 750 mg three times daily for 10 days.

RESULTS

(Intention-to-treat analysis). Forty-eight patients were enrolled in the ranitidine group; 47 in the omeprazole-plus-amoxicillin group. Mean follow-up was 576 days (77 to 730). Ulcer recurrence rate was 31.3% in the ranitidine group (group 1) versus 6.37% in the eradication group (group 2; p = 0.0018). More patients had recurrent bleeding in group 1 (8.3%) than in group 2 (4.2%) but we were not able to show a statistically significant difference with respect to recurrent bleeding between groups (p = 0.29). Definite cure of H. pylori infection was achieved in 89.3%.

CONCLUSIONS

Cure of H. pylori infection reduces recurrence of peptic ulcer and therefore rebleeding more effectively than does long-term maintenance therapy with an H2 blocker.

Reteplase (r-PA): a new plasminogen activator

Reteplase (r-PA) is a genetically engineered deletion mutant of wild-type tissue-type plasminogen activator. The structural differences lead to different functional properties, such as a prolonged half-life. The compound demonstrated good thrombolytic efficacy in in vitro as well as in animal studies. In angiographically controlled patency studies (GRECO, GRECO-2 RAPID-1, RAPID-2), the double-bolus application scheme was established, and a superior patency profile for reteplase in comparison to alteplase was demonstrated. Mortality studies established reteplase as a safe drug with a 30-day mortality at least equivalent to streptokinase (INJECT) and very similar to alteplase (GUSTO-3). A possible advantage may be the double-bolus application without a need for weight adjustment, especially in a prehospital setting. Thus, reteplase can be regarded as an excellent alternative to streptokinase or alteplase for thrombolytic therapy in acute myocardial infarction.

Acute ulcer bleeding. A prospective randomized trial to compare Doppler and Forrest classifications in endoscopic diagnosis and therapy

The aim of our prospective randomized study involving 100 patients was to investigate whether Doppler ultrasound can be used to select patients at risk for ulcer rebleeding. Ulcers in the Forrest group classified as having a visible vessel or a clot were treated prophylactically by injection with epinephrine solution. In the Doppler group, in contrast, only ulcers with a positive Doppler signal were treated endoscopically. In the Doppler group, rebleeds occurred significantly less frequently (2%, P < 0.03) than in the Forrest group (14%). Emergency surgery was only necessary in the Forrest group (0% vs 5%; P = 0.02). Bleeding-related mortality was 0% and 4% (P = 0.15) and the overall mortality 0% and 10% (P = 0.02), in the Doppler and Forrest groups, respectively. These results appear to show that Doppler-based injection treatment is superior to endoscopic treatment based exclusively on the Forrest classification. In our study, Doppler-based local endoscopic treatment reduced the danger of a rebleed and thus the number of emergency operations and the overall mortality.

The use of electronic autoradiography in radiopharmacy

The use of Microchannel Plate Analysers (Instant Imager, Canberra Packard), the so called Electronic Autoradiography, in Radiopharmacy is described. The system can be used for quality control of radiopharmaceuticals as well as for scientific research purposes. Quantitative analysis of 2-dimensional radioactive samples of all radionuclides used in Nuclear Medicine (especially 99mTc) can be performed in a very short time with little effort. Advantages and limitations for radiopharmaceutical work are described.

[Aortoduodenal fistula as the cause of gastrointestinal hemorrhage]

The aortoenteric fistula is one of the rare causes of gastrointestinal bleeding. A 73 year old patient presented with a secondary fistula after implantation of a synthetic graft. The diagnosis was confirmed by endoscopy. At elective laparotomy, a communication between the graft and the duodenum was discovered. Principally the combination of gastrointestinal bleeding and aortic graft is always suspicious of an aortoenteric fistula. The treatment must be surgical.

Endoscopic biliary stenting for the palliation of pancreatic cancer: results, survival predictive factors, and comparison of 10-French with 11.5-French gauge stents

OBJECTIVES

To compare the efficacy and complications of different stent lengths and diameters in the palliation of jaundice caused by pancreatic cancer, as well as investigate survival predictive factors and the success of endoscopic therapy.

METHODS

This study summarizes our results with 103 pancreas cancer patients treated by endoscopic plastic biliary stenting, of whom 87 were followed up until death or the time of writing. Before therapy, bilirubinemia, tumor primary size, presence of distant metastases, and signs of duodenal involvement were evaluated as prognosis risk factors. In a retrospective, nonrandomized fashion, we compared the efficacy and complications (especially clogging) of 10-French versus 11.5-French gauge stents and of "short" (< or = 8 cm) versus "long" (> or = 9 cm) prostheses.

RESULTS

Thirty six men and 51 women (median age 74 yr) with pancreatic cancer were analyzed. Stenting could abolish jaundice or make it imperceptible (bilirubinemia < 3 mg %) in 74 patients (85%). Median bilirubinemia after treatment decreased from 13.9 mg/dl to 1.0 mg/dl. Hospital mortality was 2.7%. The commonest long term complication was clogging, which occurred 66 times in 33 patients. Median stent patency was 3 and 4 months for 10-F gauge and 11.5-F gauge stents, respectively (p > 0.05). When analyzing the patients who were alive 6 months after therapy, the clogging rate was 46% and 55% for 10-F and 11.5-F stents, respectively (p > 0.05). The length also did not influence stent patency. The only risk factor assessed before therapy, which independently predicted survival, was the presence of distant metastases. Median survival for patients with metastatic disease was 2.5 months and 9 months for those without metastases (p = 0.0015).

CONCLUSIONS

We conclude that 10-F and 11.5-F stents have the same efficacy in the palliative management of malignant obstructive jaundice due to cancer of the pancreas. Detection of distant metastases is the best outcome predictive factor in these patients and should be regarded as a restriction to the insertion of biliary metal stents.

[Endoscopic laser lithotripsy for difficult calculi after unsuccessful extracorporeal shock wave lithotripsy]

INTRODUCTION

More than 97% of common bile duct stones can be successfully managed by endoscopic papillotomy, mechanical lithotripsy and extracorporeal shock-wave lithotripsy. In this study, we evaluate the role of laser lithotripsy after failure of the above mentioned endoscopic methods.

PATIENTS AND METHODS

Eighteen patients (15F, 3M; median age = 69 (28-83) years) were treated by endoscopic laser lithotripsy after ESWL failure. We employed a Rhodamine-6 G laser with a stone-tissue recognizing system. The laser fibers were cholangioscopically (direct vision) or blindly (under plain fluoroscopic control) placed.

RESULTS

Seventeen patients were treated endoscopically and one was successfully managed percutaneously after failure of the transpapillary approach. Fourteen (78%) were stone-free after a mean of 1.56 laser therapy sessions alone. Two additional patients were successfully managed after partial fragmentation with combined treatment (mechanical lithotripsy: n = 1, electrohydraulic lithotripsy: n = 1). Overall, 89% of the patients were freed from their calculi. Cholangitis occurred once and the mortality was zero.

CONCLUSIONS

We conclude that laser lithotripsy is an effective and safe treatment alternative in a highly selected patient population with difficult bile duct stones and considerable surgical risk.

Endoscopic stenting in obstructive jaundice due to liver metastases: does it have a benefit for the patient?

BACKGROUND/AIMS

The goal of this report is to describe our experience with the palliative endoscopic treatment of jaundice occurring in the setting of liver and hilar metastases of a distant primary malignancy.

MATERIAL AND METHODS

We retrospectively analyzed the clinical course of 29 consecutive patients with metastatic tumors not originating in the hepatobiliopancreatic area, who were treated by endoscopic retrograde cholangiopancreatography with endoprostheses insertion.

RESULTS

We achieved a complete follow-up in 24 out of the 29 patients (11 women, median age 69 years). The primary tumor site was the colorectum in 15 patients, stomach in 4, lung in 2, breast and prostate in 1 and one patient had a lymphoma. The median bilirubinemia before therapy was 16 (1.8-31) mg/dl and the median minimum serum bilirubin reached after stenting was 2.6 (0.3-11.5) mg/dl. Stent dysfunction was observed in 33.5% of the patients and stent change was necessary 13 times. The median survival after therapy was 4 (2.5-19) months for patients with colon tumors and 3 (0.5-12) months in patients with other cancers. An improvement in the quality of life was obtained in 75% of the patients after endoscopic treatment.

CONCLUSIONS

Endoscopic stenting should be attempted even on patients with obstructive jaundice due to liver metastases.

Using the SF-36 and Euroqol on an elderly population

An important methodological issue in measuring health-related quality of life is whether instruments such as SF-36 and EQ can be used on an elderly population. This paper aims to test the completion, reliability and validity of the SF-36 and Euroqol on an elderly female population, and to compare them with the OPCS Disability Survey. Three hundred and eighty women aged 75 and over participated in a randomized controlled trial of the use of clodronate provided the sample. As part of the trial, patients were asked to complete the UK SF-36 and Euroqol, and the OPCS disability survey instrument administered by interview in a hospital clinic at baseline. A random subsample of respondents were retested six months later. The SF-36 achieved poorer levels of completion by dimension (68.1%-88.9%) than the OPCS (99.2%) and Euroqol (84%-93.5%) instruments. There were no major floor effects in the distribution of scores, except for the role dimensions of SF-36. Correlation between test-retest were significant for all instruments, but lower for the role dimensions and social functioning of SF-36, and these dimensions also had 95% Cls for the mean differences in excess of 10 points. There was substantial agreement between the three instruments, and evidence for their construct validity against age and recent use of health services. The sensitivities of the instruments were tested through hypothetical changes in health status. There was some evidence of greater sensitivity to lower levels of morbidity in the SF-36. Where brevity is required and the health changes are expected to be substantial, then EQ may be sufficient. For greater sensitivity SF-36 seems to have an advantage, however lower completion rates and problems with consistency suggest it requires adaptation. One solution would be to use interviewer administration. Another would be to change the SF-36 to make it more suitable for use in elderly people, although this may reduce its usefulness as a generic instrument.

Peroral laser lithotripsy of difficult intrahepatic and extrahepatic bile duct stones: laser effectiveness using an automatic stone-tissue discrimination system

OBJECTIVES

The use of laser lithotripsy with an integrated stone-tissue discrimination system is an ambitious treatment modality for bile duct stone fragmentation. The aim of our prospective study was to determine the effectiveness and safety of the laser system and to find whether it reduced the need for choledochoscopy.

METHODS

Thirty patients with complicated bile duct stones were treated perorally with a flashlamp-pulsed Rhodamine-6G dye laser and an automatic stone-tissue discrimination system. Initial treatment sessions were performed under fluoroscopic guidance in each patient and switched to choledochoscopic control if the stone could not be approached properly.

RESULTS

Eighteen of 19 patients with extrahepatic bile stones were treated under fluoroscopic control; 17 of 19 patients were successfully treated through laser therapy. In nine of the patients with intrahepatic stones (n = 11), choledochoscopy was necessary for sufficient laser lithotripsy; seven of those patients became stone-free. Twenty-four of 30 patients (80%) were stone-free after sole laser therapy. Combined with other methods, the overall success rate was 27/30 (90%). Therapy-related mortality was 0%.

CONCLUSIONS

Laser lithotripsy is effective and safe. The stone-tissue discrimination system facilitates therapy under fluoroscopic control and precludes the need for choledochoscopy, which is highly significant (p <0.001) if the calculi are extrahepatically located.

-Bile duct stenoses and leakage after cholecystectomy: endoscopic diagnosis, therapy and treatment outcome-

Minimal invasive methods compete with surgical treatment in the therapy of complications after cholecystectomy. In this retrospective study we evaluate the efficacy of endoscopically placed biliary stents in 35 patients (25 female, ten male) with biliary strictures and/or leakage after cholecystectomy. 27 patients received a 10- or 11.5-French endoprosthesis, eight patients needed a percutaneous-transhepatic-cholangio-drainage (PTCD). Four patients (11.4%) underwent a surgical therapy. Endoscopic therapy was successfully completed in 23 patients (65.7%), at which we noticed a superior result in patients with early incidenced stenosis/leakages after cholecstectomy. During a follow-up period of 1-109 months (median 28 months) two recurrent strictures (5.7%) were observed. As a complication we have seen a prosthesis-dislocation after PTCD. None of the patients died of complications related to endoscopic therapy.

Idiopathic mesenteric varices causing lower gastrointestinal bleeding

We report a case of lower gastrointestinal bleeding caused by idiopathic mesenteric varices. A 25-year-old man presented with a history of two episodes of lower gastrointestinal bleeding without transfusion. Colonoscopy revealed varices of the entire colon and terminal ileum. Intravariceal blood flow was demonstrated by dopplersonography. Vascular abnormalities were excluded by selective angiography of the upper and lower mesenteric artery. No therapy was given without a new episode of bleeding and there has been no further bleeding to date (a period of 14 months). Mesenteric varices are a rare cause of lower gastrointestinal bleeding, almost always associated with portal hypertension. The varices are idiopathic in only a few cases. The therapy depends on the intensity of bleeding, but resection is the most frequent treatment.