ABSTRACT
OBJECTIVE: Near-misses are a structural characteristic of gambling products that can be engineered within modern digital games. Over a series of preregistered experiments using an online slot machine simulation, we investigated the impact of near-miss outcomes on subjective ratings (motivation, valence) and two behavioral measures (speed of gambling, bet size). METHOD: Participants were recruited using Prolific and gambled on an online three-reel slot machine simulator that delivered a one in three rate of X-X-O near-misses. Study 1 measured trial-by-trial subjective ratings of valence and motivation (Study 1a, n = 169; Study 1b, n = 148). Study 2 (n = 170) measured spin initiation latencies as a function of the previous trial outcome. Study 3 (n = 172) measured bet size as a function of the previous trial outcome. RESULTS: In Study 1a, near-misses increased the motivation to continue gambling relative to full-misses, supporting Hypothesis 1. On valence ratings, near-misses were rated significantly more positively than full-misses, in the opposite direction to Hypothesis 2; this effect was confirmed in a close replication (Study 1b). In Study 2, participants gambled faster following near-misses relative to full-misses, supporting Hypothesis 3. In Study 3, participants significantly increased their bet size following near-misses relative to full-misses, supporting Hypothesis 4. CONCLUSION: Across all dependent variables, near-miss outcomes yielded statistically significant differences from objectively equivalent full-miss outcomes, corroborating the "near-miss effect" across both subjective and behavioral measures, and in the environment of online gambling. The unexpected findings on valence ratings are considered in terms of boundary conditions for the near-miss effect, and competing theoretical accounts based on frustration/regret, goal generalization, and skill acquisition. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
Subject(s)
Gambling , Motivation , Humans , Gambling/psychology , Male , Female , Adult , Young Adult , Adolescent , Middle AgedABSTRACT
The post-reinforcement pause (PRP) is an operant effect in which response latencies increase on trials following the receipt and consumption of reward. Human studies demonstrate analogous effects in electronic gambling machines that utilise random ratio reinforcement schedules. We sought to identify moderators of the human PRP effect, hypothesising that the magnitude of gamblers' PRPs is moderated by the type of reinforcing outcome (genuine wins vs. losses-disguised-as-wins [LDWs] vs. free-spin bonus features) and individuals' level of gambling immersion, a cognitive state linked to problem gambling. Experienced slot machine users (N = 53) played a real slot machine for 20 min. The dependent variable was defined as the time delay in the initiation of each bet ("Spin Initiation Latency"; SIL). Using 80% of trials, a linear model was fit regressing SIL on the independent variables (outcome type, immersion, and outcome-by-immersion interaction), and a larger group of covariates (participant ID, trial number, winnings, etc.) selected using double-robust LASSO-regularised regression. The previously unseen 20% of cases were used to validate the model. Positively reinforcing outcome types (wins, LDWs, bonus spins) showed significantly larger SILs than losses, indicating a PRP effect. Immersion did not predict response latencies, but win-by-immersion and LDW-by-immersion interactions indicated that pauses were greater among more immersed participants. The small number of free-spin bonus features showed similar trends that were not statistically significant. These results indicate that gamblers immersed in play remained sensitive to in-game reinforcement (contrary to a prevailing account), and provide guidance for researchers bridging laboratory research and real-world behaviour.
ABSTRACT
The development and sustainability of second-generation biorefineries are essential for the production of high added value compounds and biofuels and their application at the industrial level. Pretreatment is one of the most critical stages in biomass processing. In this specific case, hydrothermal pretreatments (liquid hot water [LHW] and steam explosion [SE]) are considered the most promising process for the fractionation, hydrolysis and structural modifications of biomass. This review focuses on architecture of the plant cell wall and composition, fundamentals of hydrothermal pretreatment, process design integration, the techno-economic parameters of the solubilization of lignocellulosic biomass (LCB) focused on the operational costs for large-scale process implementation and the global manufacturing cost. In addition, profitability indicators are evaluated between the value-added products generated during hydrothermal pretreatment, advocating a biorefinery implementation in a circular economy framework. In addition, this review includes an analysis of environmental aspects of sustainability involved in hydrothermal pretreatments.
Subject(s)
Steam , Water , Biomass , Cost-Benefit Analysis , Biofuels , LigninABSTRACT
Modern slot machines are among the more harmful forms of gambling. Psychophysiological measures may provide a window into mental processes that underpin these harms. Here we investigated pupil dilation derived from eye tracking as a means of capturing changes in sympathetic nervous system arousal following outcomes on a real slot machine. We hypothesized that positively reinforcing slot machine outcomes would be associated with increases in arousal, reflected in larger pupil diameter. We further examined the contribution of game luminance fluctuations on pupil diameter. In Experiment 1A, experienced slot machine gamblers (N = 53) played a commercially-available slot machine in a laboratory for 20 minutes while wearing mobile eye tracking glasses. Analyses differentiated loss outcomes, wins, losses-disguised-as-wins, and (free-spin) bonus features. Bonus features were associated with rapid increases in pupil diameter following the onset of outcome-related audiovisual feedback, relative to losses. In Experiment 1B, luminance data were extracted from captured screen videos (derived from Experiment 1A) to characterize on-screen luminance changes that could modulate pupil diameter. Bonus features and wins were associated with pronounced and complex fluctuations in screen luminance (≈50 L and ≈25L, respectively). However, the pupil dilation that was observed to bonus features in Experiment 1A coincided temporally with only negligible changes in screen luminance, providing partial evidence that the pupil dilation to bonus features may be due to arousal. In Experiment 2, 12 participants viewed pairs of stimuli (scrambled slot machine images) at luminance difference thresholds of ≈25L, ≈50L, and ≈100L. Scrambled images presented at luminance differences of ≈25L and greater were sufficient to cause pupillary responses. Overall, pupillometry may detect event-related changes in sympathetic nervous system arousal following gambling outcomes, but researchers must pay careful attention to substantial in-game luminance changes that may confound arousal-based interpretations.
Subject(s)
Gambling , Arousal/physiology , Humans , PupilABSTRACT
AIM: This study compares long-term mandibular growth between a group of Beckwith-Wiedemann Syndrome (BWS) patients who underwent glossectomy at an early age and a group of patients not operated. METHODS: Cephalometric measurements were performed in BWS patients comparing the data obtained between a group of patients operated at an early age and a group of non-operated patients who declined surgery. Statistics included independent sample T-test. RESULTS: Twenty-four out of 78 BWS patients followed since birth completed longitudinal cephalometric x-rays at age 5, 10 and 15. Eighteen patients needed early surgery. Eleven families accepted glossectomy at 2.3 ± 1.3 years of age; seven declined surgery. No differences in mandibular growth were found between the two groups. Inclination of maxillary incisors results were statistically greater in the non-operated group (operated compared to the non-operated group: 103.58 ± 11.30 Vs 108.98 ± 12.47; p-value 0.0168 at 5; 107.06 ± 7.98 Vs 115.14 ± 7.05; p-value 0.0206 at 10; 109.80 ± 4.68 Vs 116.75 ± 5.28; p-value 0.0233 at 15). CONCLUSION: Macroglossia has no role in the post-natal mandibular overgrowth in BWS and mandibular overgrowth is part of the syndrome. Therefore, early glossectomy does not change mandibular growth and does not prevent the development of class III skeletal malocclusion in these patients.
Subject(s)
Beckwith-Wiedemann Syndrome , Macroglossia , Beckwith-Wiedemann Syndrome/complications , Beckwith-Wiedemann Syndrome/surgery , Cephalometry , Child, Preschool , Glossectomy , Humans , Infant , Macroglossia/surgery , Mandible/diagnostic imaging , Mandible/surgeryABSTRACT
BACKGROUND: Objective data on chemosensitive disorders during COVID-19 are lacking in the Literature. METHODS: Multicenter cohort study that involved four Italian hospitals. Three hundred and forty-five COVID-19 patients underwent objective chemosensitive evaluation. RESULTS: Chemosensitive disorders self-reported by 256 patients (74.2%) but the 30.1% of the 89 patients who did not report dysfunctions proved objectively hyposmic. Twenty-five percentage of patients were seen serious long-lasting complaints. All asymptomatic patients had a slight lowering of the olfactory threshold. No significant correlations were found between the presence and severity of chemosensitive disorders and the severity of the clinical course. On the contrary, there is a significant correlation between the duration of the olfactory and gustatory symptoms and the development of severe COVID-19. CONCLUSIONS: Patients under-report the frequency of chemosensitive disorders. Contrary to recent reports, such objective testing refutes the proposal that the presence of olfactory and gustatory dysfunction may predict a milder course, but instead suggests that those with more severe disease neglect such symptoms in the setting of severe respiratory disease.
Subject(s)
Betacoronavirus , Coronavirus Infections/complications , Olfaction Disorders/diagnosis , Pneumonia, Viral/complications , Sensory Thresholds , Taste Disorders/diagnosis , Adult , Aged , Aged, 80 and over , COVID-19 , Cohort Studies , Female , Humans , Italy , Male , Middle Aged , Olfaction Disorders/virology , Pandemics , SARS-CoV-2 , Severity of Illness Index , Taste Disorders/virology , Young AdultABSTRACT
Flow activities (e.g. sports and gaming) have been associated with positive affect and prolonged engagement. In the gambling field, modern electronic gaming machines (EGMs, including modern slot machines) have drawn concern as a potentially flow-inducing activity that may be associated with gambling-related harms. Current research has heavily relied on self-reported flow, and further insights may be afforded by physiological methods. We present data from three separate experiments in which self-reported gambling flow and cardiac pre-ejection period (PEP; a measure of sympathetic nervous system arousal) were examined. Male undergraduate participants gambled on a genuine EGM in a laboratory setting for a period of at least 15 min, and completed the Flow subscale of the game experience questionnaire (GEQ). Aggregated data were analyzed using multilevel regression. Although EGM gambling was not associated with significant changes in PEP across participants, we found that self-reported flow states were associated with significant decreases in PEP during the first five minutes of EGM use. Thus, participants who experienced flow showed a greater sympathetic nervous system response to the onset of gambling. Though these effects were consistent in experiments 1 and 2, in experiment 3 the effect was inverted during the same time window. We conclude that flow during EGM gambling appears to be associated with early changes in sympathetic nervous system activity, but stress that more research is needed to characterize boundary conditions and moderating factors.
ABSTRACT
BACKGROUND AND AIMS: Immersion during slot machine gambling has been linked to disordered gambling. Current conceptualizations of immersion (namely dissociation, flow and the machine zone) make contrasting predictions as to whether gamblers are captivated by the game per se ('zoned in') or motivated by the escape that immersion provides ('zoned out'). We examined whether selected eye-movement metrics can distinguish between these predictions. DESIGN AND SETTING: Pre-registered, correlational analysis in a laboratory setting. Participants gambled on a genuine slot machine for 20 minutes while wearing eye-tracking glasses. PARTICIPANTS: Fifty-three adult slot machine gamblers who were not high-risk problem gamblers. MEASUREMENTS: We examined self-reported immersion during the gambling session and eye movements at different areas of the slot machine screen (the reels, the credit window, etc.). We further explored these variables' relationships with saccade count and amplitude. FINDINGS: The ratio of dwell time on the game's credit window relative to the game's reels was positively associated with immersion (t(51) = 1.68, P = 0.049 one-tailed, R2 = 0.05). Follow-up analyses described event-related changes in these patterns following different spin outcomes. CONCLUSIONS: Immersion while gambling on a slot machine appears to be associated with active scanning of the game and a focus on the game's credit window. These results are more consistent with a 'zoned in' account of immersion aligned with flow theory than a 'zoned out' account based on escape.
Subject(s)
Eye-Tracking Technology/psychology , Gambling/psychology , Adult , Female , Humans , Male , Middle Aged , Motivation , Reinforcement, Psychology , Reward , Young AdultABSTRACT
The "winner-loser effect" refers to a phenomenon in testosterone research where the outcome of a social competition induces increases (wins) and/or decreases (losses) in testosterone levels. Here, we sought to test to what extent changes in testosterone occur in response to gambling behavior. More specifically, we hypothesized that the winner-loser effect would extend to slot machine gambling as a solitary (noncompetitive) gambling activity in players who "anthropomorphized" the slot machine, thus treating the machine as a human opponent. Male participants (n = 113) were recruited into a quasi-experimental design involving 15 min of authentic slot machine gambling, incentivized by a $10 cash bonus for participants who finished in profit. In addition to salivary measures of testosterone, salivary cortisol and self-reported anthropomorphization of the slot machine were tested as potential moderators. Contrary to predictions, winning and losing slot machine sessions did not exert significant differential effects on testosterone, and this pattern was not moderated by cortisol levels or slot machine anthropomorphization. Exploratory analyses tested relationships between subjective gambling experiences in the sessions and testosterone change. Higher positive affect and flow predicted greater testosterone declines from pre- to postgambling. The testosterone results add to a growing literature on the boundary conditions of the winner-loser effect and inform future studies on testosterone reactivity in relation to gambling and disordered gambling. The tendency to anthropomorphize slot machines is a neglected cognitive distortion in gambling that merits further study. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Subject(s)
Gambling/psychology , Testosterone/metabolism , Gambling/metabolism , Humans , Hydrocortisone/metabolism , Male , Saliva/chemistry , Self Report , Social Behavior , Young AdultABSTRACT
UNLABELLED: Beckwith-Wiedemann syndrome (BWS) is the most common (epi)genetic overgrowth-cancer predisposition disorder. Given the absence of consensual recommendations or international guidelines, the Scientific Committee of the Italian BWS Association (www.aibws.org) proposed these recommendations for the diagnosis, molecular testing, clinical management, follow-up and tumor surveillance of patients with BWS. The recommendations are intended to allow a timely and appropriate diagnosis of the disorder, to assist patients and their families, to provide clinicians and caregivers optimal strategies for an adequate and satisfactory care, aiming also at standardizing clinical practice as a national uniform approach. They also highlight the direction of future research studies in this setting. With recent advances in understanding the disease (epi)genetic mechanisms and in describing large cohorts of BWS patients, the natural history of the disease will be dissected. In the era of personalized medicine, the emergence of specific (epi)genotype-phenotype correlations in BWS will likely lead to differentiated follow-up approaches for the molecular subgroups, to the development of novel tools to evaluate the likelihood of cancer development and to the refinement and optimization of current tumor screening strategies. CONCLUSIONS: In this article, we provide the first comprehensive recommendations on the complex management of patients with Beckwith-Wiedemann syndrome.
Subject(s)
Beckwith-Wiedemann Syndrome/diagnosis , Beckwith-Wiedemann Syndrome/therapy , Beckwith-Wiedemann Syndrome/genetics , Beckwith-Wiedemann Syndrome/physiopathology , Genetic Testing , Humans , Hypoglycemia/therapy , Macroglossia/therapy , Neoplasms/diagnosisABSTRACT
The enzymatic starch hydrolysis and bioethanol production from a variety of sweet potato developed for bioenergy purposes (K 9807.1) on the basis of its high starch yields, was studied. Drying at 55°C and 95°C of sweet potato neither affected the sugar content nor the starch enzymatic hydrolysis efficiency. Simultaneous saccharification and ethanol fermentations for dry matter ratio of sweet potato to water from 1:8 to 1:2 (w/v) were studied. Fresh sweet potato and dried at 55°C (flour) were assayed. At ratios of 1:8, similar results for fresh sweet potato and flour in terms of ethanol concentration (38-45 g/L), fermentation time (16 h) and sugar conversion (~ 100%) were found. At higher dry matter content, faster full conversion were observed using flour. A higher ratio than that for fresh sweet potato (1:2.2) did not improve the final ethanol concentration (100 g/L) and yields. High ethanol yields were found for VHG (very high gravity) conditions. The sweet potato used is an attractive raw matter for fuel ethanol, since up to 4800 L ethanol per hectare can be obtained.
ABSTRACT
The energy consumption for different operative conditions and configurations of the bioethanol production industrial process from an experimental variety of sweet potato (Ipomea batatas) K 9807.1 was evaluated. A process simulation model was developed using SuperPro Designer® software. The model was based on experimental data gathered from our laboratory experiments and technology and equipment suppliers. The effects of the dry matter ratio of sweet potato to water, the fermentation efficiency, and sweet potato sugar content, on the energy consumption (steam and electricity) were respectively evaluated. All factors were significant. The best ratio of dry matter to total water to work with fresh sweet potato was 0.2 kg dry sweet potato/kg water, as for greater ratios was not found a significant reduction in energy consumption. Also, the drying of the sweet potato previous its processing was studied. It presented an energy consumption greater than the energetic content of the bioethanol produced.
Subject(s)
Biofuels , Ethanol/metabolism , Ipomoea batatas/metabolism , Analysis of Variance , Fermentation , Flour , Models, Theoretical , Thermodynamics , Time FactorsABSTRACT
Introdução: o ensino superior brasileiro em Odontologia apresenta duas realidades distintas: o aluno que se intenta formar e aquele que efetivamente se forma. Essa dualidade ocorre pelas necessidades do mercado, pelos interesses comerciais das universidades privadas e outros fatores, enquanto as Diretrizes Curriculares Nacionais do Curso de Graduação em Odontologia apontam em outra direção. Objetivo: explanar sobre as diretrizes curriculares nacionais do curso de graduação em Odontologia mostrando as disciplinas e propostas do curso. Metodologia: a explanação sobre as diretrizes e as propostas será dada por meio da comparação da resolução CNE/CES, de 19 de fevereiro de 2002, com o projeto pedagógico da Universidade de São Paulo, São Paulo, SP, Brasil. A escolha desta faculdades e deu pela sua tradição, pelo número de docentes com linhas de pesquisa que se destacam no cenário odontológico nacional, e, por ser uma universidade pública situada em um centro reconhecidamente de maior poder econômico. Conclusão: o projeto apresentado mostra-se adequado quando comparado com a resolução do Conselho Nacional de Educação.
Introduction: higher education in Brazil in Dentistry presents two distinct realities: the student who intends to form and one that effectively builds. This duality occurs by market needs, the commercial interests of private universities and other factors such as the National Curriculum Guidelines for Undergraduate Dental point in another direction. Aim: this paper seeks to explain about the national curriculum guidelines for the graduation course in Dentistry shown their disciplines and proposals for the graduation course in Dentistry. Methodology: the explanation of the guidelines and proposals will be given by comparing the Resolution CNE/CES, of 19 February 2002, with the pedagogical dental school in Brazil, the University of São Paulo, São Paulo, SP, Brazil. The choice of this option is given by tradition, by the number of professors, with research areas that stand out in the dental setting and being a national public university located in a recognized center of greater economic power. Conclusion: the project presented is appropriate when compared to the National Education Council resolution.
Subject(s)
Humans , Curriculum/standards , Universities , Education, Dental/standards , Brazil , Education, Dental/legislation & jurisprudence , Time FactorsABSTRACT
Este trabalho resume as alterações ocorridas na história da odontologia no Brasil entre os anos de 1856, quando ocorre o primeiro registro por escrito relacionando quais as exigências que se faziam para o exercício da odontologia no país até o ano de 1931 quando um currículo mínimo para todas as instituições que contassem com cursos superiores de odontologia é estabelecido. Esta tese aborda ainda as alterações pelas quais passou o nome da profissão, desde o seu aparecimento como arte ou ofício até o seu definitivo estabelecimento como profissão autônoma. Entre os anos de 1856 e 1931 houveram 10 alterações significativas no currículo exigido, até o estabelecimento do currículo mínimo e o título obtido pelo concluinte do curso passou por seis nomes distintos. A legislação que incide sobre a profissão de cirurgião-dentista neste período passou por seis alterações. A conclusão da tese é a de que os problemas que a odontologia moderna enfrenta são semelhantes àqueles enfrentados desde o começo da profissão, e que estes problemas são reflexos da maneira como a odontologia se desenvolveu no Brasil.
This thesis summarizes the changes that occurred in the history of dentistry in Brazil between 1856, when the first written requirements regarding the practice of dentistry in the country can be found until 1931 when a minimum curriculum is established to any institution that provided a dentistry course. It also approaches the changes that the name of the profession has suffered, since its beginning as an art or trade, until its definite establishment as an autonomous profession. Between the years of 1856 and 1931 there were 10 relevant changes at the curriculum and the title obtained by those who successfully concluded the course has been changed six times. The legislation regarding the dentist profession in Brazil suffered during those years six times. The conclusion is that the problems faced by modern Brazilian dentistry are similar to those which existed at its beginning, and they are a consequence of the way the profession was developed in the country.
Subject(s)
Universities , History of Dentistry , Legislation, DentalABSTRACT
Milk fat/protein degrading microorganisms were isolated from different locations of a dairy wastewater treatment system with the goal of developing an inoculum for bioaugmentation strategies. Eight isolates, identified by 16S rRNA gene sequence analysis as belonging to the genera Bacillus, Pseudomonas, and Acinetobacter, were tested for their ability to remove COD and protein from a milk-based medium (3000 mg/L COD) and compared to a commercial bioaugmentation inoculum. The Acinetobacter isolate exhibited a pellet-type growth in liquid culture, a property that could potentially aid in the separation of microbes and liquid phase following treatment. Based on the individual degradation capacity and growth behavior of the isolates, three microorganisms were further selected and tested together. This consortium exhibited a COD removal similar to the commercial inoculum (57% and 63%, respectively), but higher protein (consortium: 93%; commercial inoculum: 54%), and fat removals (consortium: 75%; commercial inoculum: 38%).
Subject(s)
Acinetobacter/metabolism , Bacillus/metabolism , Dairying , Pseudomonas/metabolism , Waste Disposal, Fluid/methods , Water Purification/methods , Acinetobacter/genetics , Bacillus/genetics , Base Sequence , Biodegradation, Environmental , Carbon/metabolism , DNA Primers/genetics , Milk Proteins/metabolism , Molecular Sequence Data , Pseudomonas/genetics , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
The effectiveness of a commercial inoculum for degrading a dairy wastewater with high fat content was evaluated, and compared with an activated sludge inoculum from a dairy wastewater treatment pond. Both inocula reached similar chemical oxygen demand removal in batch experiments. The population dynamics was also studied by determining heterotrophic counts. Predominant microorganisms were differentiated by colony morphology and genomic fingerprinting (BOX-PCR) analysis. The higher population diversity and the wider range of CO2 production rate observed in batch reactors inoculated with activated-sludge, indicated that microorganisms from this inoculum were well adapted and may have had synergic activity for the degradation of the dairy effluent. When the bioreactor was operated with the commercial inoculum in continuous mode, according to its microbial growth kinetics, other microorganisms became predominant. These results showed that inoculated microorganisms did not persist in the open system and periodic addition of microorganisms may be needed to achieve a high performance treatment.
Subject(s)
Bacteria, Aerobic/metabolism , Fats/metabolism , Waste Disposal, Fluid/methods , Water Pollutants/metabolism , Animals , Bacteria, Aerobic/cytology , Biodegradation, Environmental , Bioreactors/microbiology , Cattle , Fats/analysis , Industrial Waste/analysis , Models, Biological , Water Pollutants/chemistry , Water Purification/methodsABSTRACT
The aerobic fat biodegradation potential and growth characteristics of a commercial and a native inoculum (activated sludge from a dairy wastewater treatment pond), were evaluated. Batch tests were conducted with a medium based on butter oil, as the sole source of carbon, and mineral salts. Residual fat, biomass and CO(2) production were measured. Overall fat removal values were above 78% for both inocula. The growth kinetics of the commercial and native inocula followed Haldane and Monod models respectively. Both inocula showed a similar behaviour when butter oil concentration was under 360 mg/l; at higher values, the difference between the growth rates increased as a consequence of the inhibition exhibited by the commercial inoculum. The selection of an inoculum for bioaugmentation of bioreactors in the wastewater treatment requires a comprehensive knowledge of their degradation ability and tolerance to fluctuating compounds and of the operational conditions that will be utilized.
Subject(s)
Bacteria, Aerobic/metabolism , Fats/metabolism , Milk/chemistry , Sewage/microbiology , Waste Disposal, Fluid/methods , Water Pollutants, Chemical/metabolism , Water Purification/methods , Animals , Bacteria, Aerobic/growth & development , Biodegradation, Environmental , Biomass , Carbon Dioxide/analysis , Dairying/methodsABSTRACT
OBJECTIVES: This study assesses the mechanisms of apoptosis in patients after on-pump coronary artery bypass graft surgery and the potential involvement of the endogenous cardiac peptide urocortin as a cardiomyocyte salvage mechanism. We have previously described the mechanisms of apoptosis after ischemia-reperfusion injury in the rat heart and shown that endogenous urocortin is cardioprotective. Here we extend these findings to the human heart exposed to ischemic-reperfusion injury. METHODS: Two sequential biopsy specimens were obtained from the right atriums of 24 patients undergoing coronary artery bypass grafting at the start of grafting and 10 minutes after release of the aortic clamp. Apoptosis was identified by means of immunocytochemical colocalization between terminal deoxynucleotidyl transferase-mediated nick end-labeling positivity and active caspase-3. Immunostaining for active caspase-9 and caspase-8 was performed to identify the pathways of apoptosis induction. Urocortin and adenosine triphosphate-dependent potassium channel expression was also assessed by means of immunocytochemistry. RESULTS: Myocyte apoptosis (<0.1% before coronary artery bypass grafting) was increased after coronary artery bypass grafting and reperfusion and was greater in patients with longer periods of cardioplegic arrest (3.3% +/- 0.5% with <55 minutes and 5.1% +/- 0.9% with 85-100 minutes, P <.001). Processing of caspase-9 was always more pronounced than that of caspase-8 (P <.05). Cardioplegic arrest was also associated with increased urocortin expression (up to 29% +/- 3.5% vs <3% in samples obtained before coronary artery bypass grafting, P <.001) but only in nonapoptotic myocytes. These and surrounding viable myocytes also showed increased Kir6.1 adenosine triphosphate-dependent potassium channel expression. CONCLUSIONS: Cardioplegic arrest and subsequent reperfusion result in cardiomyocyte apoptosis, largely through mitochondrial injury, as well as exclusive urocortin expression in viable cells. This finding might suggest a cardioprotective role for endogenous urocortin in human subjects.