[Cystic echinococcosis and hepatocellular carcinoma--a coincidence? A case report]. / Zystische Echinokokkose und hepatozelluläres Karzinom--zufällige Koinzidenz? Ein Fallbericht.

INTRODUCTION: The coincidence of echinococcosis and hepatocellular carcinoma (HCC) is quite rare. We report the case of a 45-year-old man who was admitted to our hospital because of abdominal pain in the right upper quadrant and jaundice. Clinical features and diagnostics: There was no history of weight loss or fever. No abdominal mass was palpable. The laboratory reports showed increased transaminase levels. Ultrasonography revealed an inhomogenous, cystic lesion measuring 6 cm in diameter in the segments VI and VII. Serology for echinococcosis was negative, alpha-fetoprotein (AFP) was considerably increased. CT scan showed a solid mass of 3,7 cm in diameter adjacent to the cystic lesion. THERAPY AND COURSE: Anthelminthic therapy with albendazole caused a massive increase of cholestasis parameters and treatment had to be stopped. The simultaneous occurrence of serologically negative cystic echinococcosis and HCC was suspected and partial liver resection was performed. Histological examination confirmed both diagnoses and tumor resection in healthy tissue. 5 months after resection CT scan showed multicentric HCC affecting the whole liver. Palliative therapy with sorafenib was established. DISCUSSION: The coincidence of HCC and cystic echinococcosis in the non-cirrhotic liver of a young man is a rare event. Despite resection in healthy tissue multicentric HCC was diagnosed 5 months later. Only few cases of simultaneous occurrence of HCC and echinococcosis have been published so far. Some authors considered echinococcosis as a trigger for HCC. A causal link between both entities has not been demonstrated until now.

Degenerated human intervertebral discs contain autoantibodies against extracellular matrix proteins.

Degeneration of intervertebral discs (IVDs) is associated with back pain and elevated levels of inflammatory cells. It has been hypothesised that discogenic pain is a direct result of vascular and neural ingrowth along annulus fissures, which may expose the avascular nucleus pulposus (NP) to the systemic circulation and induce an autoimmune reaction. In this study, we confirmed our previous observation of antibodies in human degenerated and post-traumatic IVDs cultured in vitro. We hypothesised that the presence of antibodies was due to an autoimmune reaction against specific proteins of the disc. Furthermore we identified antigens which possibly trigger an autoimmune response in degenerative disc diseases. We demonstrated that degenerated and post-traumatic IVDs contain IgG antibodies against typical extracellular proteins of the disc, particularly proteins of the NP. We identified IgGs against collagen type II and aggrecan, confirming an autoimmune reaction against the normally immune privileged NP. We also found specific IgGs against collagens types I and V, but not against collagen type III. In conclusion, this study confirmed the association between disc degeneration and autoimmunity, and may open the avenue for future studies on developing prognostic, diagnostic and therapy-monitoring markers for degenerative disc diseases.

Increased level of antibodies cross-reacting with Ves v 5 and CRISP-2 in MAR-positive patients.

BACKGROUND: Anti-sperm antibodies (ASA) have been described to be involved in immunological infertility. A possible antigen for ASA is the human cysteine-rich secretory protein 2 (CRISP-2), a sperm surface protein important in sperm-oocyte interaction. Furthermore, anti-CRISP-2 antibodies were shown to decrease fertility rates in vitro. Recently, we have reported cross-reacting antibodies recognizing CRISP-2 and antigen 5 from yellow jacket venom (Ves v 5) in human serum. METHODS: Here, we investigated anti-Ves v 5 and CRISP-2 antibodies in sera from two groups of donors: MAR+ and MAR- patients. RESULTS: A higher incidence of allergy against hymenoptera venom was found in MAR+ patients. Interestingly, affinity-purified ASA from MAR+ patients' sera reacted against both Ves v 5 and CRISP-2, leading to sperm immobilization. Immunofluorescence analysis showed that ASA bound to the sperm surface, including the head part where CRISP-2 is localized. CONCLUSION: Taken together, these results showed a higher incidence of antibodies cross-reacting with Ves v 5 and CRISP-2 in MAR+ patients. This leads to the hypothesis that MAR+ patients may have a higher risk to develop wasp allergy.

Cross-reactions vs co-sensitization evaluated by in silico motifs and in vitro IgE microarray testing.

BACKGROUND AND OBJECTIVE: Using an in silico allergen clustering method, we have recently shown that allergen extracts are highly cross-reactive. Here we used serological data from a multi-array IgE test based on recombinant or highly purified natural allergens to evaluate whether co-reactions are true cross-reactions or co-sensitizations by allergens with the same motifs. METHODS: The serum database consisted of 3142 samples, each tested against 103 highly purified natural or recombinant allergens. Cross-reactivity was predicted by an iterative motif-finding algorithm through sequence motifs identified in 2708 known allergens. RESULTS: Allergen proteins containing the same motifs cross-reacted as predicted. However, proteins with identical motifs revealed a hierarchy in the degree of cross-reaction: The more frequent an allergen was positive in the allergic population, the less frequently it was cross-reacting and vice versa. Co-sensitization was analyzed by splitting the dataset into patient groups that were most likely sensitized through geographical occurrence of allergens. Interestingly, most co-reactions are cross-reactions but not co-sensitizations. CONCLUSIONS: The observed hierarchy of cross-reactivity may play an important role for the future management of allergic diseases.

Dimeric IVIG contains natural anti-Siglec-9 autoantibodies and their anti-idiotypes.

BACKGROUND: Intravenous immunoglobulin (IVIG) preparations are increasingly used for the treatment of autoimmune and chronic inflammatory diseases. Naturally occurring autoantibodies against Siglec-9 and Fas are thought to contribute to the anti-inflammatory effects of IVIG via cell death regulation of leukocytes and tissue cells. Dimeric IVIG fractions are suspected to contain idiotypic (Id)-anti-idiotypic complexes of antibodies, which might also include anti-Siglec-9 and anti-Fas autoantibodies. METHODS: Dimeric IVIG fractions were separated from monomeric IVIG by size-exclusion chromatography and remonomerized by low pH treatment. Binding studies of total, monomeric, and dimeric IVIG were performed using surface plasmon resonance and flow cytometry on primary human neutrophils. RESULTS: Anti-Siglec-9 and anti-Fas autoantibodies were contained in both monomeric and dimeric IVIG fractions, but anti-Siglec-9 antibodies were highly enriched in dimeric IVIG. The propensity to engage in dimer formation was paratope dependent. IVIG binding to Siglec-9 was specific and sialylation independent. Interestingly, we detected anti-idiotypic antibodies (anti-Ids) against anti-Siglec-9 autoantibodies in dimeric, but not in monomeric fractions of IVIG. CONCLUSIONS: Our study supports the concept that idiotype-anti-idiotype (Id-anti-Id) interactions contribute to the dimer formation in IVIG preparations. To our knowledge, this is the first description of Id-anti-Id dimers of death receptor-specific antibodies in IVIG. Such Id-anti-Id interactions might determine the activity of immunomodulatory antibodies present both in IVIG and the patient.

Monomeric and dimeric IgG fractions show differential reactivity against pathogen-derived antigens.

Polyvalent Ig preparations, derived from the pooled plasma of thousands of healthy donors, contain a complex mix of both 'acquired' and natural antibodies directed against pathogens as well as foreign and self/auto antigens (Ag). Depending on their formulation, donor pool size, etc., liquid Ig preparations contain monomeric and dimeric IgG. The dimeric IgG fraction is thought to represent mainly idiotype-antiidiotype Ab pairs. Treatment of all IgG fractions at pH 4 effectively monomerizes the IgG dimers resulting in separated idiotype-antiidiotype Ab pairs and thus in a comparable F(ab')(2) binding site availability of the different IgG fractions. Previously, we identified an increased anti-self-reactivity within the monomerized dimer fraction. This study addressed if, among the different IgG fractions, an analogous preferential reactivity was evident in the response against different pathogen-derived protein and carbohydrate antigens. Therefore, we assessed the activity of total unseparated IgG, the monomeric and dimeric IgG fractions against antigenic structures of bacterial and viral antigens/virulence factors. All fractions showed similar reactivity to protein antigens except for exotoxin A of Pseudomonas aeruginosa, where the dimeric fraction, especially when monomerized, showed a marked increase in reactivity. This suggests that the production of antiidiotypic IgG antibodies contributes to controlling the immune response to certain categories of pathogens. In contrast, the monomeric IgG fractions showed increased reactivity towards pathogen-associated polysaccharides, classically regarded as T-independent antigens. Taken together, the differential reactivity of the IgG fractions seems to indicate a preferential segregation of antibody reactivities according to the nature of the antigen.

Inhibition of ongoing allergic reactions using a novel anti-IgE DARPin-Fc fusion protein.

BACKGROUND: Aggregation of the high-affinity IgE receptor (FcεRI) with the low-affinity IgG receptor (FcγRIIb) on basophils or mast cells has been shown to inhibit allergen-induced cell degranulation. Molecules cross-linking these two receptors might therefore be of interest for the treatment of allergic disorders. Here, we demonstrate the generation of a novel bispecific fusion protein efficiently aggregating FcεRI-bound IgE with FcγRIIb on the surface of basophils to prevent pro-inflammatory mediator release. METHODS: Alternative binding molecules recognizing receptor-bound human IgE were selected from DARPin (designed ankyrin repeat protein) libraries. One of the selected DARPins was linked to the Fc-part of a human IgG(1) antibody for binding to FcγRIIb. RESULTS: The resulting anti-IgE DARPin-Fc fusion protein was not anaphylactogenic and inhibited allergen-induced basophil activation in whole blood assays. Both binding moieties of the fusion protein, namely the anti-IgE DARPin as well as the IgG(1) Fc-part, were required to achieve this inhibitory effect. Most importantly, inhibition was faster and more efficient than with Omalizumab, a humanized anti-IgE antibody currently used for the treatment of severe asthma. CONCLUSION: This novel anti-IgE DARPin-Fc fusion protein might represent a potential drug candidate for preventive or immediate treatment of allergic reactions.

[Colocutaneous fistula after a PEG procedure with introducer technique and gastropexy]. / Kolokutane Fistel nach PEG-Anlage mittels Introducer-Technik mit Gastropexie.

INTRODUCTION: The pull-PEG (percutaneous endoscopic gastrostomy) is the most commonly used procedure for PEG placement. Alternative methods may be used in patients with an obstructed oesophagus. We here present the case of an unusual complication during PEG placement with the new introducer technique and gastropexy. CASE REPORT: A 74-year-old men with progressive thymus cell carcinoma was referred for a PEG procedure. Since the tumour stenosis in the oesophagus was only passable with a slim-sight endoscope (5,9 mm), we decided in favour of the direct PEG method with gastropexy. The procedure was performed without any complications. 35 days later we changed the balloon catheter and were able to easily inflate the balloon. Surprisingly, the X-ray performed thereafter, revealed a misplacement of the catheter in the colon without any notable contrast medium in the stomach. Although the patient expressed no complaints, he underwent surgery on the same day proving the colocutaneous fistula. There were no signs of peritonitis. The patient's postoperative recovery was uneventful. DISCUSSION: Pull-PEG requires an intact oesophageal passage. The spread of bacteria and tumour cells is a possible risk factor. Direct punction PEG might be better in these cases. This method is not a standard procedure, but the recent implementation of an additional gastropexy represents a significant improvement. We experienced a rare complication, which was first described in 1987. However, this case is the first documented complication in association with gastropexy. This case shows that even gastropexy does not prevent colon interposition. Therefore, an endoscopic or radiological control of the tube placement after changing seems to be necessary.

Allergen cross reactions: a problem greater than ever thought?

BACKGROUND: Cross reactions are an often observed phenomenon in patients with allergy. Sensitization against some allergens may cause reactions against other seemingly unrelated allergens. Today, cross reactions are being investigated on a per-case basis, analyzing blood serum specific IgE (sIgE) levels and clinical features of patients suffering from cross reactions. In this study, we evaluated the level of sIgE compared to patients' total IgE assuming epitope specificity is a consequence of sequence similarity. METHODS: Our objective was to evaluate our recently published model of molecular sequence similarities underlying cross reactivity using serum-derived data from IgE determinations of standard laboratory tests. We calculated the probabilities of protein cross reactivity based on conserved sequence motifs and compared these in silico predictions to a database consisting of 5362 sera with sIgE determinations. RESULTS: Cumulating sIgE values of a patient resulted in a median of 25-30% total IgE. Comparing motif cross reactivity predictions to sIgE levels showed that on average three times fewer motifs than extracts were recognized in a given serum (correlation coefficient: 0.967). Extracts belonging to the same motif group co-reacted in a high percentage of sera (up to 80% for some motifs). CONCLUSIONS: Cumulated sIgE levels are exaggerated because of a high level of observed cross reactions. Thus, not only bioinformatic prediction of allergenic motifs, but also serological routine testing of allergic patients implies that the immune system may recognize only a small number of allergenic structures.

Time-lapse imaging of in vitro myogenesis using atomic force microscopy.

Myoblast therapy relies on the integration of skeletal muscle stem cells into distinct muscular compartments for the prevention of clinical conditions such as heart failure, or bladder dysfunction. Understanding the fundamentals of myogenesis is hence crucial for the success of these potential medical therapies. In this report, we followed the rearrangement of the surface membrane structure and the actin cytoskeletal organization in C2C12 myoblasts at different stages of myogenesis using atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). AFM imaging of living myoblasts undergoing fusion unveiled that within minutes of making cell-cell contact, membrane tubules appear that unite the myoblasts and increase in girth as fusion proceeds. CLSM identified these membrane tubules as built on scaffolds of actin filaments that nucleate at points of contact between fusing myoblasts. In contrast, similarly behaving membrane tubules are absent during cytokinesis. The results from our study in combination with recent findings in literature further expand the understanding of the biochemical and membrane structural rearrangements involved in the two fundamental cellular processes of division and fusion.

miR-17 and miR-20a temper an E2F1-induced G1 checkpoint to regulate cell cycle progression.

The stringent regulation of cell cycle progression helps to maintain genetic stability in cells. MicroRNAs (miRNAs) are critical regulators of gene expression in diverse cellular pathways, including developmental patterning, hematopoietic differentiation and antiviral defense. Here, we show that two c-Myc-regulated miRNAs, miR-17 and miR-20a, govern the transition through G1 in normal diploid human cells. Inhibition of these miRNAs leads to a G1 checkpoint due to an accumulation of DNA double-strand breaks, resulting from premature temporal accumulation of the E2F1 transcription factor. Surprisingly, gross changes in E2F1 levels were not required to initiate the DNA damage response and checkpoint, as these responses could occur with a less than twofold change in E2F1 protein levels. Instead, our findings indicate that the precise timing of E2F1 expression dictates S-phase entry and that accurate timing of E2F1 accumulation requires converging signals from the Rb/E2F pathway and the c-Myc-regulated miR-17 and miR-20a miRNAs to circumvent a G1 checkpoint arising from the untimely accumulation of E2F1. These data provide a mechanistic view of miRNA-based regulation of E2F1 in the context of the emerging model that miRNAs coordinate the timing of cell cycle progression.

Waveguide excitation fluorescence microscopy: a new tool for sensing and imaging the biointerface.

A novel biosensing and imaging technique, the waveguide excitation fluorescence microscope, has been developed for the dynamic and quantitative investigation of bio-interfacial events in situ, ranging from ligand-receptor binding to focal adhesion formation in cell-surface interactions. The technique makes use of the evanescent field created when light travels in a mono-mode, planar optical waveguide to excite fluorescence in the near interface region. Advantages of the technique include high target sensitivity for fluorescence detection (femtomolar range), high surface specificity (ca. 100 nm perpendicular to the waveguide), large area analysis with submicron resolution, 'built-in' calibration of fluorescent light gain, and the capability to perform multi-colour imaging in situ and in real time. In this work, the sensitivity of the system has already been demonstrated through dynamic measurements of the streptavidin-biotin binding event to below 20 pM concentrations, signal to noise comparisons with conventional fluorescence microscopy have shown more than a 10-fold improvement, and surface specificity of the technique has also been illustrated in a comparison of fibroblast focal adhesion images. Thus, this new tool can be used to illuminate processes occurring at the interface between biology and synthetic surfaces in a unique manner.

Examination, prevention and treatment of osteoporosis in patients with inflammatory bowel disease: recommendations and reality.

BACKGROUND: Patients with inflammatory bowel disease (IBD) are at increased risk of developing osteopenia and osteoporosis. Our aim was to evaluate the current practices of examination, prevention and treatment of osteoporosis in IBD patients in a routine clinical setting. METHODS: A total of 154 consecutive patients with IBD (63 female, 91 male; 36 ulcerative colitis, 115 Crohn's disease, 3 indeterminate colitis), referred to two gastroenterological units for scheduled follow-up examinations, were included. Patient charts were evaluated regarding bone densitometry already performed and any prophylactic or therapeutic interventions in cases of low bone mineral density. RESULTS: Bone mineral density (BMD) measurements had been performed only in 38 patients (25%). BMD was abnormally low in 27 of the examined patients (71%), 20 of whom had osteopenia and seven had osteoporosis. Among the subgroup of patients on long-term steroid therapy (77 patients), 30 had been referred to bone densitometry during the course of disease, and 21 of them were found to have low bone mineral density. Preventive measures were prescribed in 12 patients (9% of the whole study population). In the majority of the patients with low bone mineral density, calcium and vitamin D were used as treatment. CONCLUSIONS: Despite the high prevalence of osteopenia and osteoporosis in patients with IBD, only a minority of these patients were included in a structured program in accordance with modern guidelines for diagnosing and preventing this extraintestinal complication in a routine clinical setting.

[Indications and results of endoscopic examinations in intensive care units]. / Indikation und Resultate der Endoskopie auf Intensivstationen.

The aim of the study was to analyze retrospectively all endoscopies performed on 3 intensive care units in a tertiary referral center with more than thousand beds during a period of ten years. The study evaluates all endoscopies with regard to indication and findings. In the years 1989-1998 a total of 326 endoscopic examinations was performed, most of them were done as an upper gastrointestinal endoscopy (88%). In more than 87% the indication was a suspected gastrointestinal bleeding. The most frequent findings consisted in ulcers of the stomach or duodenum and esophageal varices, then followed by Mallory-Weiss-lesions, esophagitis and erosive gastritis. The etiology of gastrointestinal bleeding was similar to that of non intensive care patients. Specific causes of bleeding such as esophagitis caused by nasogastric tubes were only found in 3% of all bleedings. The numbers of endoscopies on the 3 intensive care units were increasing during the ten year period, however the numbers of the patients treated on the intensive care units were also increasing, but the increase of endoscopies was not always parallel to the rising number of intensive care patients.

Recombinant anti-idiotypic antibodies inhibit human natural anti-glycoprotein (GP)IIb/IIIa autoantibodies.

Anti-idiotypic antibodies (anti-Id) have been described against idiotypes expressed on various autoantibodies. Since an immunoregulatory effect has been postulated for anti-Id, modulation of the anti-Id response in autoimmune disease may be of interest. In chronic immune thrombocytopenic purpura (AITP), autoantibodies directed mainly against platelet membrane glycoprotein (GP) IIb/IIIa cause platelet destruction by Fc-mediated phagocytosis or by complement lysis. We have previously reported on the generation of two recombinant anti-GPIIb/IIIa autoantibody fragments (PDG-X, PDG-B), that are specific for conformationally intact GPIIb/IIIa and inhibit binding of autoantibodies from patients with AITP. In the present study, we show that anti-GPIIb/IIIa specificities are not limited to a single individual by isolating five additional anti-GPIIb/IIIa autoantibody fragments from a second phagemid Fab library of an unrelated healthy donor. Using soluble Fab of PDG-X and PDG-B as antigens for panning Fab phagemid libraries from healthy human individuals, we isolated anti-Id phage clones specific for PDG-X or PDG-B. In addition they inhibited the binding of PDG-X or PDG-B to GPIIb/IIIa. Amino acid sequence comparison between these specific antiId and GPIIb/IIIa was performed. Generation of these anti-Id directed against pathologically relevant anti-GPIIb/IIIa autoantibodies may represent a new suitable and specific therapeutic option for the treatment of antibody-mediated AITP.

[Obstructive jaundice and acute pancreatitis due to an obstruction of the afferent loop after billroth-II-resection]. / Verschlussikterus und akute Pankreatitis durch Obstruktion der zuführenden Schlinge nach Billroth-II-Resektion.

An obstruction of the afferent loop after Billroth-II-resection is an extremely rare late complication of this procedure. We report on a 76-year-old female patient with a history of Billroth-II-resection 11 years ago who was admitted due to acute pancreatitis and obstructive jaundice. Abdominal sonography lead to the suspicion of a dilated afferent loop, which could be proven by means of magnetic resonance imaging. A tumorous lesion as cause of the obstructive jaundice was not detectable. Intraoperatively a volvulus of the small intestine and strangling adhesions near the Braun's anastomosis were seen, causing the obstruction of the afferent loop. Following reposition of the small intestine and adhesiolysis the patient gained a quick relief of symptoms and the jaundice disappeared completely.

[Colonoscopy and sigmoidoscopy in patients aged eighty years or older]. / Koloskopie und Sigmoidoskopie bei über achtzigjährigen Patienten.

BACKGROUND: The demographic development will lead to an increase in endoscopic examinations in elderly patients. Indications, feasibility and therapeutic consequences following detection of pathologic findings are important assessing the relevance of endoscopy in geriatric patients. METHODS: We analyzed all colonoscopies and sigmoidoscopies which were performed between January 1995 and December 2000 in patients older than 80 years. The parameters indication, sedation, colonoscopy completion rate, endoscopic findings, therapeutic consequences and complications were evaluated. RESULTS: A total of 951 endoscopies in patients older than 80 years (781 colonoscopies, 170 sigmoidoscopies; mean age 84.3 years) were performed. The most frequent indications were: abdominal pain (n = 144; 15 %), bleeding (n = 115; 12 %), constipation (n = 97; 10 %), anemia (n = 85; 9 %), and history of polyps (n = 78; 8 %). Sedation was used in 183 examinations (19 %), mostly with midazolam (n = 179). Colonoscopy was completed successfully to the coecum in 71 %. 214 examinations were unremarkable (23 %). Frequent pathologic findings were: diverticular disease (n = 396; 42 %), polyps (n = 256; 27 %), and colorectal carcinoma (n = 75; 8 %). Curative surgery was possible in 55 % and palliative surgery in 9 % of patients with colorectal carcinoma, respectively. A complication was observed in six patients (0.6 %), four bleedings following polypectomy, one perforation after dilatation of a stenotic tumor, and one transient neurologic deficit. CONCLUSIONS: Endoscopy of the lower gastrointestinal tract is feasible in geriatric patients with a low rate of complications. The low number of normal findings and the frequent diagnosis of colorectal carcinoma were remarkable. In spite of old age more than half of the patients with carcinoma could be operated curatively emphasizing the importance of endoscopic investigations in this age group.

Conditional autoimmunity mediated by human natural anti-Fc(epsilon)RIalpha autoantibodies?

Natural antibodies provide an early defense mechanism against pathogens, show a frequent self-reactivity, and are present throughout life. Two questions concern the physiological control of self-reactivity and the pathogenetic link to autoimmune disease. Here we propose a concept of conditional autoimmunity involving natural antibodies against the alpha chain of the high-affinity receptor for IgE (Fc(epsilon)RIalpha ). Like other natural antibodies, anti-Fc(epsilon)RIalpha antibodies are found in sera of healthy donors. We now report the first human recombinant anti-Fc(epsilon)RIalpha autoantibodies isolated by repertoire cloning from a human tonsillar IgM library. These high-affinity antibodies recognize Fc(epsilon)RIalpha on cells and trigger histamine release from freshly isolated blood basophils. However, the latter effect requires IgE removal from the Fc(epsilon)RI. The same conditional histamine release is seen when using sera from individual normal donors and affinity-purified anti-Fc(epsilon)RIalpha antibodies isolated from multidonor therapeutic IgG preparations. We propose that such anti-Fc(epsilon)RIalpha antibodies can become pathogenic and that this is dependent on the state of occupancy of the Fc(epsilon)RIalpha by its natural ligand IgE. We suggest that an imbalance between Fc(epsilon)RIalpha occupancy and natural anti-Fc(epsilon)RIalpha antibodies may be implicated in the pathogenesis of autoimmune urticaria.

Adenosine-enhanced ischemic preconditioning modulates necrosis and apoptosis: effects of stunning and ischemia-reperfusion.

BACKGROUND: Adenosine-enhanced ischemic preconditioning extends the protection of ischemic preconditioning by both significantly decreasing infarct size and significantly enhancing postischemic functional recovery. METHODS: The effects of adenosine-enhanced ischemic preconditioning on necrosis and apoptosis were investigated in the sheep heart using models of stunning (15 minutes regional ischemia, 120 minutes reperfusion) and ischemia-reperfusion (30 and 60 minutes regional ischemia, 120 minutes reperfusion). Ischemic preconditioned hearts received 5 minutes regional ischemia, 5 minutes reperfusion before ischemia. Adenosine-enhanced ischemic preconditioned hearts received a 10 mmol/L adenosine bolus (10 mL) through the left atrium coincident with ischemic preconditioning. Adenosine hearts received a 10 mmol/L bolus (10 mL) of adenosine. Regional ischemic hearts received no pretreatment. RESULTS: Minimal apoptosis (< 45 per 3,000 myocytes) was observed in the stunning models but was significantly increased with ischemia-reperfusion in regional ischemic hearts after 30 minutes (p < 0.05 versus ischemic preconditioning, adenosine, or adenosine-enhanced ischemic preconditioning) and in adenosine and ischemic preconditioned hearts after 60 minutes ischemia (p < 0.05 versus adenosine-enhanced ischemic preconditioning). DNA laddering was apparent after 60 minutes ischemia in regional ischemia, adenosine, and ischemic preconditioning but not in adenosine-enhanced ischemic preconditioned hearts. CONCLUSIONS: Adenosine-enhanced ischemic preconditioning significantly ameliorates necrosis and apoptosis in the regional ischemic blood-perfused heart.