Association of coagulation markers and antiphospholipid antibodies with ischemic and bleeding risk in patients with atrial fibrillation undergoing percutaneous coronary intervention

Background

Antiphospholipid antibodies and other coagulation markers are associated with ischemic risk in patients with coronary artery disease without oral anticoagulation (OAC).

Aim

To assess the association of antiphospholipid antibodies (aPL) and conventional markers of coagulation with ischemic and bleeding risk in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI).

Patients and methods

In this prospective single center observational cohort study, patients with AF and an indication for OAC were enrolled after PCI. Dilute Russell's viper venom time (DRVVT) was used to determine lupus anticoagulants (LA) in direct OAC-free plasma. Anti-cardiolipin IgG (aCL), IgM and anti-beta2GP-1-IgG (aβ2GP1) were analyzed by enzyme linked immunosorbent assay (ELISA). Fibrinogen C (FIBC), d-dimers and prothrombin fragments 1 and 2 (PF1+2) were measured in citrated plasma. Immature platelet fraction (IPF [%]) and absolute (IPF abs. [103/μl]) were measured in EDTA-blood. The primary ischemic outcome was defined as time to major adverse cardiovascular events (MACE: all-cause death, myocardial infarction, or stroke) assessed at 6 months. Bleeding was defined according to the International Society of Thrombosis and Haemostasis (ISTH) and the Bleeding Academic Research Consortium (BARC).

Results

158 patients were enrolled between May 2020 and May 2021. The median age was 78 years (interquartile range, IQR 72–82), 111 (70%) were male, and 39 (25%) presented with acute coronary syndrome. All Patients were treated with clopidogrel and OAC, 145 (92%) in addition with acetylsalicylic acid (ASA). 32 patients (20%) had ≥1 antiphospholipid antibody (aPL; LA: 19 [12%], aCL: 14 [9%], aβ2GP1: 2 [1%]). D-dimers were elevated in 74 patients (47%), FIBC was increased in 40 (25%) and PF1+2 in 68 patients (43%). IPF [%] was elevated in 28 (18%) and IPF abs. [103/μl] in 11 (7%). The presence of aPL was neither significantly associated with MACE, nor with bleeding risk. Elevated d-dimers were significantly associated with higher risk for MACE (HR=5.1, 95% CI [1.1; 23.4], p=0.04), major ISTH bleeding events (HR= 6.9, 95% CI [1.5; 30.8], p=0.01) and BARC bleeding type 3 or 5 (HR=6.4, 95% CI [1.4; 28.7], p=0.02). Increased levels of FIBC were associated with risk of MACE (HR= 3.6, 95% CI [1.1; 12.0], p=0.03 (Table 1).

Conclusion

In patients with AF undergoing PCI, high levels of d-dimers and fibrinogen C indicate an increased ischemic risk. Elevated d-dimers are associated with higher risk for bleeding. aPL positivity was not significantly associated with outcome possibly due to low sample size. A combined panel of biomarkers might be suitable to assess ischemic and bleeding risk in patients with AF following PCI.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Faculty of Medicine, Freiburg

Acute Toxicity of Acrylonitrile: Effect of Diet on Tissue Nonprotein Sulfhydryl Content and Distribution of 1–14C-Acrylonitrile or Its Metabolites

The influence of diet on the acute toxicity (lethality) and distribution of glutathione as measured by tissue nonprotein sulfhydryl (NPSH) concentration following acrylonitrile (ACN) treatment was studied. The tissue distribution of radiolabeled (14C) acrylonitrile or its radioactive metabolites was also determined. The diets tested were a standard laboratory rat chow; a casein-based, complete diet; and 2 diets high in saturated fat content that were either lipotrope deficient or lipotrope supplemented. The latter 2 diets were associated with decreased weight gain in the absence of ACN and increased lethality after orally administratered ACN. The increase in lethality, while most pronounced in the group fed the lipotrope-deficient, high-fat diet, was also seen in rats fed the purified control diet. The high-fat diets were associated with increases in brain and liver NPSH concentrations (mg NPSH/100 g body weight). Following oral administration of 1–14C-ACN, blood contained the highest specific activity. In terms of fraction of administered dose, liver was found to contain the highest total fraction. In the tissues measured, a majority of radioactivity appeared bound to trichloroacetic acid (TCA) insoluble components. The sequence of tissue activity (nCi 14C per g or ml) was as follows: blood > stomach > liver, duodenum, lung, kidney > brain > adrenal. While diet affected toxicity, it did not modify this general ranking.

Neoplasms in Rats Ingesting Acrylonitrile for Two Years

Male Sprague-Dawley rats ingested 0, 20 ppm, or 500 ppm of acrylonitrile in drinking water for 2 years. Rats receiving 500 ppm of acrylonitrile exhibited early mortality and retarded weight gain. Tumors of Zymbal's gland were associated in dose-response fashion with acrylonitrile exposure. Age-associated incidence of pituitary adenomas containing immunoreactive prolactin was decreased in acrylonitrile-treated rats. A decrease in pituitary tumor incidence also was observed in rats treated with low doses of acrylonitrile, suggesting that reduction in this tumor frequency was not because of early death. No increases were found in tumors of other organ systems, but a trend toward development of forestomach papillomas was noted in rats receiving the highest concentration of acrylonitrile.

REDOX-SENSITIVE TRANSCRIPTION FACTORS EGR-1 AND SP1 IN THE PATHOGENESIS OF EXPERIMENTAL GASTRIC ULCER

Changes in redox status of gastric mucosa cells are the main pathogenic factor of gastric erosion and gastric ulcer development. Pro-oxidants can affect cell transcription activity via changes in redox-sensitive transcription factors. Egr-1 and Sp-1 may regulate the transcription of genes that are associated with the pathogenesis of gastric ulcer (growthfactors, cell cycle regulators, etc.). The aim of the present study was to reveal the possible involvement of zinc-finger transcriptionfactors Egr-1 & Sp-1 in the molecular mechanisms underlying gastric lesions caused by aspirin administration and stress. Gastric ulcer was induced in male rats (180-220 g) by immobilization stress combined with water-immersion (IMO-WI) or aspirin gavage (10 mg/100 g). The rats were euthanized 20 min, 1 hour, or 3 hours following the ulcerogenic factor exposure. Protein expression was determined by Western blot analysis and RT-PCR; levels of SH-groups of proteins were determined by method of Ellman et al. Development of gastric ulcer lesions was associated with twofold (P < 0.05) decrease in concentration of protein SH-groups in the rat gastric mucosa. These changes were accompanied by significant (P < 0.05) increase in the expression of Egr-1 mRNA and protein in both gastric ulcer models, and the changes in IMO-WI were more profound. Increased levels of Egr-1 were associated with the decrease in SpI protein levels. We showed for the first time the competitive interaction between redox-sensitive transcription factors Egr-1 and Sp1 in the early phases of gastric ulcer development, which might facilitate inducible transcriptional activity of Egr-1 at the expense of reduction in Sp1 activity.

A mutein of human basic fibroblast growth factor TGP-580 accelerates colonic ulcer healing by stimulating angiogenesis in the ulcer bed in rats

Previously, we reported that TGP-580, a mutein of human basic fibroblast growth factor (bFGF), accelerated the healing of gastric and duodenal ulcers in rats. In the present study, we examined the effect of TGP-580 on the healing of colonic ulcers. In male Sprague Dawley rats, ulcers were induced in the colon 6 cm from the anus by enema of 50 μl of 3% N-ethylmaleimide, a sulfhydryl alkylator. The lesions were examined under a dissecting microscope (x10). The concentration of bFGF in the ulcerated colon was measured by enzyme immunoassay, and both the distribution of bFGF and the density of microvessels in the ulcer bed were examined by immunohistochemical staining. The content of bFGF in the ulcerated colon was markedly increased associated with ulcer healing, and ulcer healing was significantly delayed by intravenous administration of a monoclonal antibody for bFGF (MAb 3H3) once daily for 10 days. In the ulcer bed, many cells such as fibroblasts, vascular endothelial cells and macrophages were positively stained with bFGF antiserum. TGP-580, human bFGF or dexamethasone was given intracolonally twice daily for 10 days, starting the day after ulcer induction. TGP-580 (0.2 - 20 μg/ml, 200 μl/rat) dose-dependently accelerated ulcer healing, and its effect was more than 10 times stronger than that of human bFGF. Density (μm/0.01 mm(2)) of microvessels in the ulcer bed was significantly increased by treatment with TGP-580, and there was a good correlation between the density of microvessels and the decrease of ulcerated area (R(2) = 0.633). On the other hand dexamethasone (20 μg/ml) inhibited angiogenesis in the ulcer bed and delayed ulcer healing. These results suggest that angiogenesis in the ulcer bed plays an important role in ulcer healing, and that bFGF mutein TGP-580 accelerated colonic ulcer healing, at least in part, by stimulating angiogenesis, whereas glucocorticoids may delay the healing by inhibiting angiogenesis.

Aging impairs transcriptional regulation of vascular endothelial growth factor in human microvascular endothelial cells: implications for angiogenesis and cell survival

In some tissues, aging impairs angiogenesis and reduces expression of vascular endothelial growth factor A (VEGF), a fundamental regulator of angiogenesis. We previously examined angiogenesis in aging and young gastric mucosa in vivo and in vitro and showed that an imbalance between expressions of VEGF (pro-angiogenic factor) and endostatin (anti-angiogenic protein) results in an aging-related impairment of angiogenesis in rats. However, the human relevance of these findings, and whether these mechanisms apply to endothelial cells derived from other tissues, is not clear. Since P-STAT3 and P-CREB are transcription factors that, in association with HIF-1α, can activate VEGF gene expression in some cells (e.g., liver cancer cells, vascular smooth muscle cells), we examined the expression of these two proteins in human dermal microvascular endothelial cells (HMVECs) derived from aging and neonatal individuals. We examined and quantified in vitro angiogenesis, expression of VEGF, P-STAT3, P-CREB and importin-α in HMVECs isolated from neonates (neonatal) and a 66 year old subject (aging). We also examined the effects of treatment with exogenous VEGF and endostatin on in vitro angiogenesis in these cells. Endothelial cells isolated from aging individuals had impaired angiogenesis (vs. neonatal endothelial cells) and reduced expression of VEGF mRNA and protein. Aged HMVECs also had reduced importin-α expression, and reduced expression and nuclear translocation of P-STAT3 and P-CREB. Reduced VEGF gene expression in aged HMVECs strongly correlated with the decreased levels of P-STAT3, P-CREB and importin-α in these cells. Our study clearly demonstrates that endothelial cells from aging individuals have impaired angiogenesis and reduced expression of VEGF likely due to impaired nuclear transport of P-STAT3 and P-CREB transcription factors in these cells.

[The role of Src-tyrosine kinases in increasing vascular permeability during experimental ulcerative colitis]

We have shown the increase of Src(Tyr416) phosphorylation in rat colonic mucosa at early stages of 6% iodoacetamide-induced ulcerative colitis (UC), while the level of Src protein expression was not changed. Pretreatment of rats with Src inhibitor PP1 (0.2 mg/100 g, subcutaneously) decreased the colonic vascular permeability (VP) (P < or = 0.001) and pSrc(Tyr416) level during iodoacetamide-UC. Iodoacetamide-induced autophosphorylation and upregulation of VEGFR-2 was associated with Src activation in colonic mucosa of rats. Sequentially, protein-protein interaction between beta-arrestine2 and VE-cadherine was enhanced, that might be a reason of colonic endothelium barrier disruption. We concluded that Src plays a key role in the mechanisms of increasing the colonic VP during experimental UC.

Aortic insufficiency due to a partial left-coronary aortic valve prolapse and the detection of two small interatrial jets after blunt thoracic trauma

Aortic valve regurgitation due to blunt thoracic trauma is a rare complication. Autopsy studies have been shown that the aortic valve is the most often lacerated one among the heart valves. Actually, we describe a case of a 47 year old man with the signs of heart failure after a blunt thoracic trauma 2 months before caused by aortic insufficiency due to a partial left-coronary aortic valve prolapse. Furthermore, transthoracic and transesophageal echocardiography revealed two small jets between the left and the right atrium.

Altered angiogenic balance in ulcerative colitis: a key to impaired healing?

Angiogenesis is an essential component of ulcer healing since it assures delivery of oxygen and nutrients to the healing site. Previous studies demonstrated increased serum and tissue levels of vascular endothelial growth factor (VEGF, the most potent angiogenic growth factor) in patients with active ulcerative colitis (UC) and animal models of UC. However, there is no explanation why the healing of UC-related mucosal injury is impaired despite increased expression of VEGF. Expression of angiogenesis inhibitors, angiostatin and/or endostatin, in UC has not been determined before. We examined expression of VEGF, angiostatin, and endostatin in two models of experimental UC. The results revealed that in addition to increased VEGF, both endostatin and angiostatin levels were markedly (2-3-folds) increased in colonic mucosa at early stage of experimental UC. This is the first demonstration that colitis triggers increase in angiostatin and endostatin levels. The results may explain why mucosal lesions heal slowly despite increased VEGF levels, and may provide a novel and mechanistic insight into UC.

Depression in Croatian Type 2 diabetic patients: prevalence and risk factors. A Croatian survey from the European Depression in Diabetes (EDID) Research Consortium

AIMS

To determine the prevalence rate of and risk factors for depression in Croatian Type 2 diabetic patients.

METHODS

Depressive mood was examined in 384 randomly selected outpatients with Type 2 diabetes. Center for Epidemiological Studies Depression Scale (CES-D) and Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) were used to identify depressive disturbances. The groups with CES-D > or = 16 and < 16 were compared with respect to demographic, psychological and clinical characteristics. Regression analysis was used to determine risk factors for depression.

RESULTS

Of the examined patients, 22% had CES-D scores > or = 16, and in 33% of them clinical depression was confirmed by the psychiatric interview. Depressed patients compared with the non-depressed ones reported more diabetes-related problems and poorer well-being (t = 6.71, P < 0.001 and t = 11.98, P < 0.001, respectively). Multiple regression analysis indicated female gender, experienced support and the level of emotional well-being to predict depression (R = 0.74, F = 15.3, P < 0.001).

CONCLUSIONS

The obtained data indicate that the prevalence rate in Croatian Type 2 diabetic patients is comparable to findings from other cultural settings. Depressive symptoms can be predicted by psychological rather than disease-related variables. Psychological care for diabetic patients may be necessary to prevent depressive symptomatology.

Increased fibrin specificity and reduced paradoxical thrombin activation of the combined thrombolytic regimen with reteplase and abciximab versus standard reteplase thrombolysis

In patients with acute myocardial infarction treated with thrombolytics, platelet activation as well as alterations of the hemostatic and fibrinolytic systems have been described favoring early infarct-related artery reocclusion. We investigated the effects of a newer thrombolytic regimen with half-dose double-bolus reteplase (2 x 5 IU, 20 patients) combined with abciximab versus full-dose reteplase (2 x 10 IU, 18 patients) on the fibrinolytic and the hemostatic system in patients with acute ST-segment elevation (in the electrocardiogram) myocardial infarction. The thrombolytic regimen with half-dose reteplase in combination with abciximab caused in vivo a lower systemic plasminemia and a lower paradoxical activation of the contact phase of the coagulation system (measured as activated factor XII); a lower paradoxical thrombin activation/generation; and a lesser extent of fibrinogen breakdown compared with the reteplase regimen. These results could be, at least in part, a possible explanation for the observed significantly lower rates of reinfarction until 7 days after enrollment and of recurrent ischemia in the combination group in the Global Use of Strategies to Open Occluded Coronary Arteries V (GUSTO V) trial.

Benefical effects of reteplase in combination with abciximab: platelet/leukocyte interactions and coagulation system

Pathophysiological aspects of acute myocardial infarction include altered hemostatic and fibrinolytic systems as well as platelet activation. Treatment with thrombolytics and GP IIb/IIIa antagonists has been described as having an additional influence on these systems. We investigated the effects of a new thrombolytic regimen with half-dose double-bolus reteplase (2 x 5 IU, 20 patients) combined with abciximab versus full dose reteplase (2 x 10 IU, 18 patients) on platelet-granulocyte complexes and on thrombin-antithrombin III complexes in patients with acute ST-segment elevation myocardial infarction. In vivo, the thrombolytic regimen with half-dose reteplase in combination with abciximab caused fewer platelet-granulocyte aggregates (measured as percentage of CD41-positive granulocytes) and a lower paradoxical activation of the coagulation system (measured as thrombin-antithrombin III complex) compared with the reteplase regimen. The combination regimen could therefore have benefical effects on platelet-induced leukocyte activation and leukocyte-mediated proinflammatory/cytotoxic effects as well as on granulocyte-induced effects on endothelium, tissue damage and coagulation. This could be, at least in part, a possible explanation for the significantly lower rates of reinfarction, recurrent ischaemia and percutaneous coronary interventions observed during the early phase after an acute myocardial infarction in the combination group in the GUSTO-V trial.

Myocardial troponin T release is associated with enhanced fibrinolysis in patients with acute coronary syndromes

Patients with acute coronary syndromes (ACS) frequently present with signs of disturbed fibrinolysis. The present study investigates the correlation of alterations in the fibrinolytic system and the amount of myocardial damage characterized by troponin release. In 85 patients with ACS markers of plasmin activation, plasminogen activator system and troponin T (TnT) were measured initially and after 48 h. Patients with TnT release (> or = 0.01 microg/l) at admission had higher TPA levels than those without release (10.2+/-0.7 ng/ml vs. 7.6+/-0.5 ng/ml; p <0.01). Additionally, patients with positive TnT had higher D-dimer levels initially (457+/-39 ng/ml vs. 316+/-22 ng/ml; p <0.01) and 48 h later (451+/-42 ng/ml vs. 275+/-37 ng/ml; p <0.01). The association of myocardial damage with a prothrombotic state and an enhanced fibrinolysis may explain the high prognostic value of troponin measurements in respect to future coronary events.

The thrombolytic paradox

Thrombolytic drugs do not only stimulate the plasmin system but also induce thrombin activation additionally to the preexisting hypercoagulative state in patients with acute myocardial infarction. Testing the in vitro-derived hypothesis of a plasmin-mediated activation of the contact phase of the coagulation leading to the procoagulant effect, several thrombolytic regimen have been evaluated. Paradoxical thrombin activation (referred to as "thrombolytic paradox") was related to absence of fibrin specificity. Highly fibrin-specific drugs like tenecteplase did not cause additional thrombin activation, while non-fibrin-specific drugs like streptokinase caused a marked additional activation of the contact phase and of thrombin. It could be shown that the thrombolytic paradox was related to the extent of systemic plasmin activation confirming the hypothesis of a plasmin-mediated factor XII/kallikrein system activation as cause of the thrombolytic paradox.

Recurrent ingrown toenails secondary to indinavir/ritonavir combination therapy

OBJECTIVE

To report five cases of ingrown toenails (IGTN) associated with indinavir/ritonavir (IDV/RTV) combination therapy.

CASE SUMMARY

The median onset of IGTN from initiation of IDV/RTV therapy was 18.4 weeks. Four patients previously received IDV, with one of these experiencing prior IGTN. All patients required surgical management of IGTN. All patients received virologic benefit from ongoing antiretroviral therapy, and the majority of patients elected to maintain IDV/RTV combination therapy. Two patients experienced recurrent IGTN while receiving ongoing IDV/RTV combination therapy.

DISCUSSION

IGTN and paronychia have previously been reported with IDV and lamivudine. IGTN in patients with HIV infection is more likely to present acutely, involve more digits, and require surgical management IDV increases retinoic acid signaling and, based on elevated IDV concentrations from concomitant RTV therapy, the risk of IGTN may be increased in patients receiving IDV/RTV combination therapy.

CONCLUSIONS

With the increasing popularity of IDV/RTV combination therapy, clinicians should be aware of the potential increase in frequency of dose-related toxicities including IGTN. Evaluation of hands and feet on physical examination should be recommended for all patients being treated with lamivudine and IDV, especially when used in combination with RTV.

The effects of an HIV-1 immunogen (Remune) on viral load, CD4 cell counts and HIV-specific immunity in a double-blind, randomized, adjuvant-controlled subset study in HIV infected subjects regardless of concomitant antiviral drugs

OBJECTIVE

We examined the activity of an HIV-1 immunogen (Remune) on viral load, CD4 cells and HIV-1 specific immunity.

METHODS

Plasma and peripheral blood mononuclear cells were obtained in a predefined random subset of subjects (n = 252) from a multicentre, double-blind, adjuvant-controlled phase III clinical endpoint study.

RESULTS

The subjects treated with the HIV-1 immunogen had a significantly greater decline in viral load at multiple time points (P < 0.05), a trend towards increased CD4+ T cell counts and significantly enhanced HIV-1 specific immune responses as measured by HIV-1 lymphocyte proliferation (P < 0.001) compared to the adjuvant control group. Furthermore, in the HIV-1 immunogen treated group, enhanced HIV-1 specific lymphocyte proliferative immune responses were associated with decreased HIV-1 plasma RNA.

CONCLUSION

These results suggest that, in a predefined, random subset of subjects, a beneficial effect of the HIV-1 immunogen was observed on viral load, CD4+ T cells, and HIV-specific immunity. These differences were observed in a background of multiple drug therapies. Ongoing trials are evaluating the effect of the combination of this HIV-1 specific, immune-based therapy with potent antiviral drug therapy on virological outcomes.

Prognostic influence of delays between exploratory and definitive laparotomy in the treatment of malignant ovarian tumors

BACKGROUND

The aim of this retrospective study was to evaluate whether a delay between a preliminary exploratory laparotomy and a definitive staging laparotomy and interval chemotherapy between the two operations affected the prognosis of ovarian cancer.

METHODS

Of 504 patients with malignant tumors of the ovary who were treated at the Department of Obstetrics and Gynecology between 1980 and 1993, there were 24 who had a delayed definitive staging laparotomy.

RESULTS

Sixteen patients did not have chemotherapy between their two operations. After definitive laparotomy, 13 patients (54.2%) were free of disease and 11 patients had residual disease (45.8%).

CONCLUSIONS

The value of chemotherapy between preliminary and definitive laparotomy in halting tumor growth was not demonstrated by the results of our analysis.

Akuter Myokardinfarkt bei Patienten mit Diabetes mellitus

Kardiovaskuläre Erkrankungen stellen bei Patienten mit Diabetes mellitus die wesentliche Ursache für Morbidität und Mortalität dar. Haupttodesursache bei Diabetikern ist der akute Myokardinfarkt. Auch nach diesem Ereignis bestehen erhöhte Mortalitätsraten und eine höhere Inzidenz für die Entwicklung einer Herzinsuffizienz versus Patienten ohne Diabetes.

Pathophysiologische Besonderheiten ergeben sich im Hinblick auf die Auswirkung des Diabetes auf die koronare Herzerkrankung mit einer myokardialen und einer vaskulären Komponente. Darüber hinaus bestehen bei Diabetikern häufig weitere Erkrankungen wie die arterielle Hypertonie, Veränderungen der Hämostase, der Fibrinolyse, korpuskulärer Blutbestandteile und der Inflammation. Nicht alle klassischen diagnostischen Kriterien des Myokardinfarkts können bei Diabetikern aufgrund der Begleiterkrankungen uneingeschränkt angewandt werden. Die Therapie hat die rasche und permanente Reperfusion der verschlossenen Koronararterie zum Ziel; dabei kommen verschiedene pharmakologische Thrombolyse-Regime und die perkutane transluminale Koronarangioplastie in Frage. Weitere Studien müssen abgewartet werden, um ein optimales Vorgehen zur Prognoseverbesserung dieser Patientenpopulation zu finden.

Gene expression and gene therapy in experimental duodenal ulceration

Gastroduodenal ulceration is still poorly understood and changes in gene expression may provide new mechanistic insights. Previously, we demonstrated that angiogenic growth factors are potent ulcer healing agents, and the synthesis of bFGF, PDGF and VEGF is enhanced early in duodenal ulcer healing. The initial molecular event in duodenal ulceration seems to be the organ-specific early release of ET-1 in the pre-ulcerogenic stages after the administration of duodenal ulcerogen cysteamine in rats. We also briefly review here data from literature indicating a central role of ET-1 in gastroduodenal ulceration. After studying the involvement of immediate early genes (e.g. egr-1, Sp1) in ulcer development, we now investigated expression of other genes in the duodenal mucosa in the early stages of chemically induced duodenal ulceration in rats. Following a brief review of principles of gene expression and gene therapy, we review our preliminary gene expression studies, involving monitoring about 1200 genes which revealed about 160 signals and prominent changes in about 30 genes in the early stages of experimental duodenal ulceration. Cysteamine enhanced ET-B receptor gene expression in 30 min, while transcription factors (MAX, STAT 3) showed increased expression in 12 h. We recently also initiated gene therapy studies to enhance the local synthesis of PDGF and VEGF to accelerate duodenal ulcer healing, using a single dose of naked DNA (ND) or adenoviral (AV) vectors of VEGF and PDGF in rats with cysteamine-induced duodenal ulcers. Gene therapy with ND or AV of VEGF or PDGF significantly accelerated chronic duodenal ulcer healing, and increased levels of VEGF and PDGF were detected by Western blotting and ELISA in duodenal mucosa after both VEGF and PDGF gene therapy. Thus, gene expression studies provide new insights into the molecular mechanisms of duodenal ulceration and VEGF or PDGF gene therapy seems to be a new option to achieve a rapid ulcer healing.

Investigation of gastroprotective compounds at subcellular level in isolated gastric mucosal cells

We tested the hypothesis that recognized gastroprotective agents exert direct protection against ethanol-induced injury in isolated rat gastric mucosal cells in vitro. If protection exists, we also wanted to identify subcellular targets in the reversible and/or irreversible stages of cell injury. Ethanol-induced cell injury was quantified by measuring plasma membrane leakage (trypan blue exclusion and lactate dehydrogenase release), mitochondrial integrity (succinic dehydrogenase), and nuclear damage (ethidium bromide-DNA fluorescence). Initial cell viability and responsiveness were estimated by the effects of carbachol, carbachol + atropine, or 16,16-dimethyl-PGE(2) on chief cell pepsinogen secretion. Enriched parietal cells were stimulated by histamine, carbachol, or histamine + IBMX. Preincubation of cells with PG, sucrose octasulfate, or the sulfhydryl compounds N-acetylcysteine, taurine, or cysteamine increased cell resistance </=21% against ethanol. Similar protection was found with low histamine concentrations, but a higher concentration aggravated ethanol toxicity. Other naturally occurring or synthetic gastroprotective agents offered partial protection or aggravated ethanol-induced cell injury. Only a few in vivo gastroprotective agents demonstrated in vitro direct cytoprotection, which involved mainly the reversible stage of cell injury (e.g., plasma membrane changes) and, less often, irreversible (e.g., mitochondrial and nuclear) damage. Our findings also indicate that a major part of the beneficial effect of gastroprotective agents is expressed at the tissue level.

Fibrin specificity and procoagulant effect related to the kallikrein-contact phase system and to plasmin generation with double-bolus reteplase and front-loaded alteplase thrombolysis in acute myocardial infarction

This study was undertaken to compare the effects of reteplase and alteplase regimens on hemostasis and fibrinolysis in acute myocardial infarction (AMI). Thrombolytic treatment in patients with AMI is hampered by paradoxical procoagulant effects that favor early reocclusion. In vivo data comparing this effect and the fibrin specificity of double-bolus reteplase and front-loaded alteplase regimens are not available. In a prospective, randomized study, 50 patients with AMI were either treated with double bolus (10 + 10 U) reteplase or with front-loaded alteplase (up to 100 mg) within 6 hours of symptom onset. Thirty apparently healthy persons served as controls. Molecular markers of coagulation and fibrinolysis were serially examined for up to 5 days. Paradoxical thrombin activation at 3 hours after initiation of therapy was comparable between reteplase and alteplase. Reteplase (65 +/- 5 U/L) and alteplase (72 +/- 8 U/L) caused significantly elevated kallikrein activity at 3 hours after adminstration (p <0.01 vs controls 30 +/- 1 U/L). Fibrin specificity was less for reteplase (p <0.05) with a decrease in fibrinogen at 3 hours to 122 +/- 27 mg/dl versus 224 +/- 28 mg/dl for alteplase (p <0.01 and p <0.05 vs controls). D-Dimer levels at 3 hours were higher (p <0.05) after reteplase (5,459 +/- 611 ng/ml) versus alteplase (3,445 +/- 679 ng/ml) (both p <0.01 vs controls 243 +/- 17 ng/ml). Plasmin generation (plasmin-antiplasmin complexes) was significantly (p <0.01) increased at 3 hours with both regimens to 27,079 +/- 3,964 microg/L (reteplase) and 19,522 +/- 2,381 microg/L (alteplase). The data from 3 hours after start of thrombolytic therapy proved less marked fibrin specificity of the reteplase regimen (in vivo) compared with front-loaded alteplase. Both regimens have a moderate procoagulant effect without differences in activation of the kallikrein system.

Review article: transcription factors and growth factors in ulcer healing

This review is focused on recent investigations demonstrating a pharmacological and pathophysiologic role in gastroduodenal ulceration for growth factors such as basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF), as well as for transcription factors. Our experiments revealed accelerated healing, without decreased gastric acid secretion, of chronic cysteamine-induced duodenal ulcers in rats treated daily for 3 weeks with intragastric administration of bFGF, PDGF or VEGF. Our recent studies also indicate a pathophysiological role of endogenous growth factors in the natural history of experimental duodenal ulcer development and healing. More recently, we investigated the genetic regulation of these growth factors in experimental duodenal ulceration. Since gene expression is most effectively controlled by transcription factors, proteins that bind to cis-acting elements of DNA and guide the binding of polymerase II to start the transcription of specific mRNA, we tested the hypothesis that the expression of IEGs and their transcription factor products, such as Egr-1 and Sp1, might precede the increased synthesis of bFGF, PDGF and VEGF in duodenal ulcer healing. Indeed, the duodenal ulcerogen cysteamine, but not its nonulcerogen and toxic analogue ethanolamine, rapidly increased duodenal (but not gastric) mucosal levels of ET-1, which was followed by enhanced expression of Egr-1 and a decrease in Sp1 in the preulcerogenic stage of duodenal ulceration. These changes in levels of ET-1 and expression of transcription factors were also accompanied by increased expression of the CDK inhibitor p21. Thus, not only growth factors such as bFGF, PDGF and VEGF, but also transcription factors such as Egr-1 and Sp1 and the cell cycle regulator p21, may play a role in the natural history of experimental duodenal ulceration.

Growth factors in ulcer healing: lessons from recent studies

Growth factors such as epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and more recently vascular endothelial growth factor (VEGF) have been used extensively to heal experimental gastric, duodenal and colonic ulcers in animal models. Encouraging results have been reported in clinical trials with EGF and bFGF. Since our laboratory has been involved with the initial ulcer healing studies with bFGF, PDGF and VEGF, we summarize here the major lessons from these studies and from literature data. These conclusions relate to the role of: 1) gastrointestinal (GI) secretion; 2) epithelial versus vascular components of the healing; 3) efficacy in the upper and lower GI tract; 4) quality of ulcer healing; as well as 5) the endogenous origin; and 6) molar potency of growth factors. Namely, among these growth factors only EGF inhibits gastric acid and stimulates duodenal bicarbonate secretion, while chronic administration of bFGF slightly enhances gastric secretion and PDGF has no effect demonstrating that potent ulcer healing can be achieved without influencing acid base and mucus secretion. This might be related to the fact that these growth factors stimulate with varying potency virtually all the cellular elements needed for ulcer healing, e.g., epithelial cell proliferation and migration by EGF > bFGF > PDGF, fibroblast proliferation by bFGF > PDGF and angiogenesis by VEGF > bFGF >> PDGF >> EGF. Conceptually, the most interesting results were obtained recently with VEGF which is virtually specific for angiogenesis, illustrating that stimulation of vascular factors is sufficient for ulcer healing because epithelial cells apparently spontaneously proliferate and migrate over a dense granulation tissue to complete the healing process. Since these growth factors directly stimulate the cell components of ulcer healing, it is probably not surprising that they are active in both upper and lower GI tract lesions, produce good quality of ulcer healing in comparison with spontaneously healed duodenal ulcers which are hypovascular and muscle regeneration is not part of natural healing. Contrary to other antiulcer drugs, these growth factors are endogenously derived and play a role in the natural history of ulcer healing, and since these relatively large peptides (18-45 kDa) are active in ng quantities, their molar potency is 2-7 million times superior to cimetidine-like drugs. Thus growth factors are endogenously derived very potent antiulcer drugs which act independently of GI secretion, are active in upper and lower GI lesions, and since they stimulate virtually all the cells of the healing process, they produce an excellent quality of ulcer healing.

Perception of the form of stimulus increment as a method in assessment of the psychophysical relationship

Among numerous procedures for determination of the psychophysical relation, one approach has seldom been applied. Essential in this method is to present a set of stimuli whose intensity increases in fixed time following different forms. The objective stimulus increment, which the subjects perceive as linear growth directly, represents the inverse psychophysical relation. In this paper the method was tested in the fields of click frequency and sound pressure. This procedure was named "Perception of the Form of Stimulus Increment in Time". In comparison to other psychophysical approaches, this one has several advantages. The principal ones are the following: (1) In assessing the psychophysical relation it is not necessary to try to measure the perceptual magnitude; and (2) the psychophysical relation is directly determined by its dynamic pattern. In this paper modifications to the method are reported which facilitate the subject's task and avoid some differences in subjects' individual approaches to the task. The modified procedure leads to results satisfactory independent of the influence of the factors irrelevant to the psychophysical relationship.

Activation of VEGF and Ras genes in gastric mucosa during angiogenic response to ethanol injury

Our previous studies demonstrated that ethanol injury triggers the angiogenic response in gastric mucosa bordering necrosis. The present study was aimed to determine whether vascular endothelial growth factor (VEGF) (a potent angiogenic peptide selectively acting on endothelial cells) and Ras (a mediator of cell proliferation and a putative regulator of VEGF expression) are involved in gastric angiogenesis after ethanol injury. We studied the angiogenic response and expression of VEGF and Ras in gastric mucosa after ethanol injury. Ethanol damage triggered 1) angiogenesis in the gastric mucosa bordering necrosis, 2) significant increases in VEGF mRNA and protein expression, and 3) significant increases in the expression of Ki-ras mRNA and Ras proteins. Neutralizing anti-VEGF antibody significantly reduced (by greater than threefold) the angiogenic response to ethanol-induced injury. Moreover, mevastatin, an inhibitor of Ras activation, completely blocked the induction of VEGF expression in cultured primary endothelial cells. Because, in other tissues, VEGF is one of the most potent angiogenic factors and VEGF expression is dependent on Ras, our data indicate that Ras and VEGF are involved in gastric mucosal angiogenesis after ethanol injury.

Radiation-induced enterocolitis: basic and applied science

We adapted and introduced in our laboratory a simplified animal model of radiation-induced enterocolitis. After a shielding of the parenchymatous organs, our dose-response studies revealed that 20 Gy x-ray radiation resulted in about 20% mortality and reproducible lesions in the terminal ileum and proximal colon. These changes are optimal for pharmacologic studies since they may be decreased or aggravated by drugs. Sucralfate dose-dependently decreased the clinical signs of enterocolitis (e.g., lethargy, diarrhea) as well as the number and area of ileal and colonic erosions and ulcers. The wet weight of the ileum and colon were also decreased by sucralfate. bFGF at the small doses used exerted a beneficial effect only on a few of the parameters of enterocolitis. Thus sucralfate, and maybe bFGF, might decrease the severity and accelerate the healing of radiation-induced enterocolitis.

The diagnostic and prognostic value of tumor angiogenesis

The "angiogenic switch" and tumor angiogenesis play a critical role in the growth and metastasis of solid tumors. Tumor angiogenesis is regulated by a balance of stimulators (e.g., VEGF, bFGF) and inhibitors of angiogenesis (e.g., angiostatin, endostatin, angiostatic steroids). Measuring angiogenesis (blood vessel density) and/or its main regulators such as VEGF and bFGF in solid tumors, or the levels of these growth factors in the serum or urine provides new and sensitive markers for tumor progression, metastasis and prognosis.

Thrombolytic therapy in acute myocardial infarction: comparison of procoagulant effects of streptokinase and alteplase regimens with focus on the kallikrein system and plasmin

BACKGROUND

Thrombolytic therapy in patients with acute myocardial infarction (AMI) is hampered by procoagulant effects. In vitro studies have indicated that plasmin stimulation activates the kallikrein-contact-phase system, resulting in thrombin activation. This prospective comparative study was designed to examine the procoagulant effects of streptokinase or alteplase in AMI.

METHODS AND RESULTS

Sixty-one patients with AMI received 1.5 million U of streptokinase or front-loaded alteplase (up to 100 mg) and systemic heparin. Twenty-four patients with AMI and no thrombolytic therapy and 30 control subjects were examined for comparison. Molecular markers of thrombin, plasmin activation, and coagulation activities were determined before therapy and serially for up to 10 days. Moderate thrombin (initial thrombin-antithrombin [TAT] complex 18+/-5 versus 4+/-0.3 microg/L, P<0.05) and kallikrein (up to 45+/-4 versus 30+/-1 U/L at 3 hours, P<0.01) activation occurs in patients with AMI. D-Dimers are increased (P<0.01), and plasmin is stimulated (P<0.01). Streptokinase and alteplase increase TAT to 50+/-17 and 51+/-18 microg/L at 3 hours and to 50+/-17 and 33+/-14 microg/L at 6 hours, respectively (P<0.01). Kallikrein activity is elevated (P<0. 01) to 76+/-5 and 71+/-7 U/L at 3 hours and 64+/-6 and 47+/-5 U/L by streptokinase and alteplase, respectively, at 6 hours. Reductions in fibrinogen and increases in D-dimers and plasmin-antiplasmin complexes are more marked (P<0.05 and 0.01) after streptokinase versus alteplase. Correlations were found among TAT, kallikrein activity, and plasmin activation (P<0.01).

CONCLUSIONS

The data indicate a more marked procoagulant action of the streptokinase regimen compared with front-loaded alteplase, thus supporting the hypothesis of a plasmin-mediated kallikrein activation with consecutive procoagulant action in vivo.

Vascular approach to gastroduodenal ulceration: new studies with endothelins and VEGF

Endothelins (ET) and VEGF/VPF (vascular endothelial growth factor/vascular permeability factor) are products mainly of endothelial cells, which are also regulated via autocrine and paracrine pathways by these peptides. As a follow-up to our focus on vascular factors in ulcer pathogenesis and healing, we review here our recent studies with ET-1 and VEGF/VPF in animal models and human subjects. Our new results demonstrated a rapid and time-dependent release of ET-1 into the systemic circulation after intragastric administration of ethanol or HCI in rats, and ethanol in humans. The ET-1 release preceded the development of hemorrhagic erosions in both species and might be used as a diagnostic tool to noninvasively quantify acute gastric mucosal lesions. The development of solitary duodenal ulcers in the rat was preceded only by an organ- (involving only the duodenum and not the stomach) and molecule-specific (induced only by cysteamine and not by the nonulcerogenic analog ethanolamine) rapid local release of ET-1. The severity of cysteamine-induced duodenal ulcers was dose-dependently decreased by pretreatment with ET-1 antibodies or antagonist bosentan. A single intragastric dose of VEGF/VPF resulted in gastroprotection against ethanol, while daily intragastric treatment with the peptide for three weeks stimulated angiogenesis in the base of cysteamine-induced duodenal ulcers and accelerated ulcer healing. Thus, modulation of vascular factors seems to be sufficient for both acute gastroprotection and chronic duodenal ulcer healing.

Quality of life following a change in therapy for diabetes mellitus

OBJECTIVE

The study objective was to evaluate and compare quality-of-life (QOL) parameters between patients with type 2 (non-insulin-dependent) diabetes mellitus who changed therapy from an oral hypoglycaemic agent (OHA) to insulin and those who remained on an OHA.

DESIGN

The World Health Organization Quality of Life Questionnaire (WHOQOL) was used to assess quality of life among 2 groups of patients with type 2 diabetes mellitus at baseline and after a 2-month follow-up period.

SETTING

The study was conducted in the outpatient department of the Vuk Vrhovac Clinic, a referral centre for registration, treatment and follow-up of patients with diabetes mellitus in Zagreb, Croatia.

PARTICIPANTS AND INTERVENTIONS

32 consecutively recruited patients with type 2 diabetes mellitus who were switched from an OHA to insulin therapy (group 1) were compared with 28 patients who remained on OHA (group 2) with respect to QOL issues. The patient groups were comparable in terms of gender, age, duration of disease, education and family status. However, patients in group 1 had glycosylated haemoglobin (HbA1c) values greater than 9.5% on average during a period of approximately 6 months, which was the criterion used for switching to insulin therapy.

MAIN OUTCOME MEASURES AND RESULTS

At baseline, various QOL ratings were higher among patients in group 2 than group 1, indicating better quality of life with respect to overall quality of life (t = -2.31, p = 0.03), physical health (t = -2.36, p = 0.02), psychological state (t = -2.01, p = 0.05) and level of independence (t = -2.75, p = 0.001), while no differences were found between groups with respect to the social domain, personal beliefs and environmental QOL aspects. After the follow-up period, the groups were comparable in all QOL aspects other than overall quality of life (t = -2.18, p = 0.03) and level of independence (t = -3.49, p = 0.001), both of which remained higher for patients in group 2. No changes in QOL parameters were detected within group 2 from baseline to the end of the 2-month follow-up period, whereas patients in group 1 showed significant improvement in psychological QOL determinants (t = -2.14, p = 0.04).

CONCLUSION

Results of the study indicate that introducing insulin therapy in patients with type 2 diabetes mellitus and sustained elevated HbA1c levels might positively affect their quality of life.

Hans Selye and the development of the stress concept. Special reference to gastroduodenal ulcerogenesis

Hans Selye has a historic role in the development of the stress concept. Before his short article in Nature in 1936, the neuroendocrine response to nonspecific injury was thought to be restricted to the release of catecholamines, as recognized by Cannon. Selye was the first to appreciate the crucial role of the adrenal cortex/hypophysis axis in the stress response. He also insisted on the nonspecificity of this neuroendocrine response, and he named the stress-causing agent "stressors". His last major contribution was the distinction between negative, that is, distress, and positive, that is, eustress reactions. The "triad of stress" (adrenal hypertrophy, gastrointestinal ulcers, thymolymphatic atrophy) was also first described by Selye, who was fascinated by the fact that in stressed rodents only gastric and not duodenal ulcers would develop. It was not until the recognition of duodenal ulcerogenic properties of propionitrile and cysteamine as well as the subsequent quantitative structure-activity studies predicting the duodenal ulcerogenic action of complex molecules that pathogenetic investigations allowed a molecular and mechanistic approach for studying the etiology and pathogenesis of duodenal ulceration. Recent studies on the role of sulfhydryls, TRH, ET, and growth factors provide new insights into central and peripheral pre-ulcer pathways. We were surprised to learn that an organ-specific ET-1 release may play a role both in ulcer induction and healing, which seems to start with the expression of immediate early genes such as egr-1 and stimulation of the local synthesis of growth factors such as bFGF and PDGF. Thus, a historic review originating with Hans Selye and extending through the next 60 years allows a cellular and molecular approach to the better understanding of stress-related disorders such as gastroduodenal ulceration.

Gastroprotection by 4-methylpyrazole against ethanol in humans

4-Methylpyrazole (4-MP), a specific inhibitor of alcohol dehydrogenase, exerts gastroprotection of unusually long duration in rats. We tested the hypothesis that pretreatment with 4-MP might protect the human gastric mucosa against alcohol-induced acute injury. Fourteen healthy volunteers received pretreatment with either 4-MP, 15 mg/kg body weight dissolved in 50 ml of orange juice, or placebo and 2 hr later 100 ml of 40% ethanol. The endoscopic appearance of the gastric mucosa was evaluated and scored (scale 0-5) and mucosal biopsies were obtained just before pretreatment and 30 min after ethanol for histologic examination and prostaglandin E2 measurement. In the 4-MP group the mean endoscopic injury score was significantly lower than that in placebo group, in both the body and the antrum. Histologically, 4-MP significantly reduced disruption of surface epithelium and completely prevented the deep hemorrhagic mucosal lesions. In the 4-MP group no changes in gastric mucosal PGE2 levels were detected. In rats, 4-MP did not inhibit gastric acid output, whereas it markedly increased the adherent gastric mucus evaluated by the alcian blue recovery method. When lipid peroxidation was induced by carbon tetrachloride in hepatic microsomes, 4-MP caused significant inhibition of malondialdehyde generation. We conclude that 4-MP provides significant protection of the human stomach against alcohol-induced acute mucosal injury. 4-MP, besides inhibiting the conversion of alcohol to acetaldehyde, might protect the gastric mucosa by increasing adherent gastric mucus and by scavenging free radicals.