Surgery of pulmonary aspergillomas in immunocompromised patients

Introduction: Pulmonary aspergillosis is a devastating complication in immunocompromised patients. Timing of surgery is controversial and depends on the patients' general condition

Surgery of pulmonary aspergillomas in immunocompromised patients

Introduction: Pulmonary aspergillosis is a devastating complication in immunocompromised patients. Timing of surgery is controversial and depends on the patients' general condition

The challenge to detect heart transplant rejection and transplant vasculopathy non-invasively - a pilot study

<p>Abstract</p> <p>Background</p> <p>Cardiac allograft rejection and vasculopathy are the main factors limiting long-term survival after heart transplantation.</p> <p>In this pilot study we investigated whether non-invasive methods are beneficial to detect cardiac allograft rejection (Grade 03 R) and cardiac allograft vasculopathy. Thus we compared multi-slice computed tomography and magnetic resonance imaging with invasive methods like coronary angiography and left endomyocardial biopsy.</p> <p>Methods</p> <p>10 asymptomatic long-term survivors after heart transplantation (8 male, 2 female, mean age 52.1 ± 12 years, 73 ± 11 months after transplantation) were included. In a blinded fashion, coronary angiography and multi-slice computed tomography and ventricular endomyocardial biopsy and magnetic resonance imaging were compared against each other.</p> <p>Results</p> <p>Cardiac allograft vasculopathy and atherosclerosis were correctly detected by multi-slice computed tomography and coronary angiography with positive correlation (r = 1). Late contrast enchancement found by magnetic resonance imaging correlated positively (r = 0.92, r²= 0.85, p < 0.05) with the histological diagnosis of transplant rejection revealed by myocardial biopsy. None of the examined endomyocardial specimen revealed cardiac allograft rejection greater than Grade 1 R.</p> <p>Conclusion</p> <p>A combined non-invasive approach using multi-slice computed tomography and magnetic resonance imaging may help to assess cardiac allograft vasculopathy and cardiac allograft rejection after heart transplantation before applying more invasive methods.</p

Delayed development of pneumothorax after pulmonary radiofrequency ablation

Acute pneumothorax is a frequent complication after percutaneous pulmonary radiofrequency (RF) ablation. In this study we present three cases showing delayed development of pneumothorax after pulmonary RF ablation in 34 patients. Our purpose is to draw attention to this delayed complication and to propose a possible approach to avoid this major complication. These three cases occurred subsequent to 44 CT-guided pulmonary RF ablation procedures (6.8%) using either internally cooled or multitined expandable RF electrodes. In two patients, the pneumothorax, being initially absent at the end of the intervention, developed without symptoms. One of these patients required chest drain placement 32 h after RF ablation, and in the second patient therapy remained conservative. In the third patient, a slight pneumothorax at the end of the intervention gradually increased and led into tension pneumothorax 5 days after ablation procedure. Underlying bronchopleural fistula along the coagulated former electrode track was diagnosed in two patients. In conclusion, delayed development of pneumothorax after pulmonary RF ablation can occur and is probably due to underlying bronchopleural fistula, potentially leading to tension pneumothorax. Patients and interventionalists should be prepared for delayed onset of this complication, and extensive track ablation following pulmonary RF ablation should be avoided

Human cardiac tissue in a microperfusion chamber simulating extracorporeal circulation - ischemia and apoptosis studies

<p>Abstract</p> <p>Background</p> <p>After coronary artery bypass grafting ischemia/reperfusion injury inducing cardiomyocyte apoptosis may occur. This surgery-related inflammatory reaction appears to be of extreme complexity with regard to its molecular, cellular and tissue mechanisms and many studies have been performed on animal models. However, finding retrieved from animal studies were only partially confirmed in humans. To investigate this phenomenon and to evaluate possible therapies in vitro, adequate human cardiomyocyte models are required. We established a tissue model of human cardiomyocytes preserving the complex tissue environment. To our knowledge human cardiac tissue has not been investigated in an experimental setup mimicking extracorporeal circulation just in accordance to clinical routine, yet.</p> <p>Methods</p> <p>Cardiac biopsies were retrieved from the right auricle of patients undergoing elective coronary artery bypass grafting before cardiopulmonary bypass. The extracorporeal circulation was simulated by submitting the biopsies to varied conditions simulating cardioplegia (cp) and reperfusion (rep) in a microperfusion chamber. Cp/rep time sets were 20/7, 40/13 and 60/20 min. For analyses of the calcium homoeostasis the fluorescent calcium ion indicator FURA-2 and for apoptosis detection PARP-1 cleavage immunostaining were employed. Further the anti-apoptotic effect of carvedilol [10 μM] was investigated by adding into the perfusate.</p> <p>Results</p> <p>Viable cardiomyocytes presented an intact calcium homoeostasis under physiologic conditions. Following cardioplegia and reperfusion a time-dependent elevation of cytosolic calcium as a sign of disarrangement of the calcium homoeostasis occurred. PARP-1 cleavage also showed a time-dependence whereas reperfusion had the highest impact on apoptosis. Cardioplegia and carvedilol could reduce apoptosis significantly, lowering it between 60-70% (p < 0.05).</p> <p>Conclusions</p> <p>Our human cardiac preparation served as a reliable cellular model tool to study apoptosis in vitro. Decisively cardiac tissue from the right auricle can be easily obtained at nearly every cardiac operation avoiding biopsying of the myocardium or even experiments on animals.</p> <p>The apoptotic damage induced by the ischemia/reperfusion stimulus could be significantly reduced by the cold crystalloid cardioplegia. The additional treatment of cardiomyocytes with a non-selective β-blocker, carvedilol had even a significantly higher reduction of apoptotis.</p

Information flows at inter-team boundaries in agile information systems development

Agile software development methods are being used on larger projects thus the study of inter-team communication are becoming an important topic of interest for researchers. This research addresses inter-team communication by exploring the tools and three different boundaries, inter-team, team and customers, and geographically separated teams. In this research, we gathered data from semi-structured face-to-face interviews which were analyzed following the grounded theory approach. Our study reveals consensus from different teams on the importance of virtual Kanban boards. Also, some teams members tend to adapt to other teams’ preferred communication tool. We observed challenges around interdependent user stories among the different teams and highlighted the problems that rise at the different boundaries. Keywords: agile information system development • inter-team communication • agile team boundary • communication • agile methods • cooperating agile team

Influence of hypothermia on right atrial cardiomyocyte apoptosis in patients undergoing aortic valve replacement

BACKGROUND: There is increasing evidence that programmed cell death can be triggered during cardiopulmonary bypass (CPB) and may be involved in postoperative complications. The purpose of this study was to investigate whether apoptosis occurs during aortic valve surgery and whether modifying temperature during CPB has any influence on cardiomyocyte apoptotic death rate. METHODS: 20 patients undergoing elective aortic valve replacement for aortic stenosis were randomly assigned to either moderate hypothermic (ModHT group, n = 10, 28°C) or mild hypothermic (MiHT group, n = 10, 34°C) CPB. Myocardial samples were obtained from the right atrium before and after weaning from CPB. Specimens were examined for apoptosis by flow cytometry analysis of annexin V-propidium iodide (PI) and Fas death receptor staining. RESULTS: In the ModHT group, non apoptotic non necrotic cells (annexin negative, PI negative) decreased after CPB, while early apoptotic (annexin positive, PI negative) and late apoptotic or necrotic (PI positive) cells increased. In contrast, no change in the different cell populations was observed over time in the MiHT group. Fas expression rose after reperfusion in the ModHT group but not in MiHT patients, in which there was even a trend for a lower Fas staining after CPB (p = 0.08). In ModHT patients, a prolonged ischemic time tended to induce a higher increase of Fas (p = 0.061). CONCLUSION: Our data suggest that apoptosis signal cascade is activated at early stages during aortic valve replacement under ModHT CPB. This apoptosis induction can effectively be attenuated by a more normothermic procedure

The challenge to verify ceramide's role of apoptosis induction in human cardiomyocytes - a pilot study

<p>Abstract</p> <p>Background</p> <p>Cardioplegia and reperfusion of the myocardium may be associated with cardiomyocyte apoptosis and subsequent myocardial injury. In order to establish a pharmacological strategy for the prevention of these events, this study aimed to verify the reliability of our human cardiac model and to evaluate the pro-apoptotic properties of the sphingolipid second messenger ceramide and the anti-apoptotic properties of the acid sphingomyelinase inhibitor amitryptiline during simulated cardioplegia and reperfusion ex vivo.</p> <p>Methods</p> <p>Cardiac biopsies were retrieved from the right auricle of patients undergoing elective CABG before induction of cardiopulmonary bypass. Biopsies were exposed to <it>ex vivo </it>conditions of varying periods of cp/rep (30/10, 60/20, 120/40 min). Groups: I (untreated control, n = 10), II (treated control cp/rep, n = 10), III (cp/rep + ceramide, n = 10), IV (cp/rep + amitryptiline, n = 10) and V (cp/rep + ceramide + amitryptiline, n = 10). For detection of apoptosis anti-activated-caspase-3 and PARP-1 cleavage immunostaining were employed.</p> <p>Results</p> <p>In group I the percentage of apoptotic cardiomyocytes was significantly (p < 0.05) low if compared to group II revealing a time-dependent increase. In group III ceramid increased and in group IV amitryptiline inhibited apoptosis significantly (p < 0.05). In contrast in group V, under the influence of ceramide and amitryptiline the induction of apoptosis was partially suppressed.</p> <p>Conclusion</p> <p>Ceramid induces and amitryptiline suppresses apoptosis significantly in our ex vivo setting. This finding warrants further studies aiming to evaluate potential beneficial effects of selective inhibition of apoptosis inducing mediators on the suppression of ischemia/reperfusion injury in clinical settings.</p

Examination of the craving for nicotine dependent on nicotine effects

In der Forschung gibt es diverse Ergebnisse und Meinungen bezüglich der Beziehung zwischen Craving und Stimulus. Deshalb war es Ziel dieser Studie zu klären, wie die Studienteilnehmer nach 8-stündiger Nikotinabstinenz und Applikation von 8mg Nikotin auf einen ihnen präsentierten Stimulus (“Rauchervideo”) reagieren. Außerdem sollte geklärt werden, ob es eine Beziehung zwischen der auf den Stimulus physiologischen Reaktion und dem subjektiv angegebenem Craving gab und ob Teilnehmer der Cue-Exposuregruppe im Gegensatz zur Vergleichsgruppe höhere visuelle Analogskalawerte (VACS)-/bzw. Questionnaire on Smoking Urges (QSU)-Werte aufwiesen. Darüber hinaus kam die Frage auf, ob es signifikante Korrelationen zwischen dem Nikotinspiegel der Probanden und dem für das Craving relevanten Parametern des Fagerstöm-Tests für Nikotinabhängigkeit (FTND), QSU und VACS-Skalen gab. Obwohl die Studienteilnehmer annähernd gleiche Ausgangsbedingungen (Alter, Geschlecht, Zig/d, Rauchdauer, Probandenverteilung und FTND-Wert) hatten, ergab sich keine signifikante Beziehung zwischen der Nikotinkonzentration und den physiologischen Parametern des Cravings (Hautleitfähigkeitsniveau „SCL“ und Pulsamplitude) über alle Sitzungen. Dafür könnte es mehrere Erklärungen geben: neben der relativ kurzen Abstinenzzeit vor der Nikotingabe kann auch die Tatsache, dass die Probanden nicht isoliert in einem Raum, sondern von anderen Teilnehmern jederzeit abgelenkt werden konnten, einen Rolle spielen. Außerdem sind die Ergebnisse der einzelnen Teilnehmer schwer zu interpretieren, da keine neutralen Stimuli als Vergleichsmöglichkeit verwendet wurden. Ebenfalls zeigte sich bei der Auswertung der Ergebnisse keine signifikante Korrelation zwischen subjektiv angegebenem Craving und physiologisch gemessener Reaktion bei Präsentation des Stimulus “Rauchervideo”. Die Tatsache, dass das Rauchervideo an sich wenige Probanden subjektiv angesprochen hat, kann daran liegen, dass nicht alle Menschen durch optische, manche nur durch olfaktorische Reize zum Craving verleitet werden. Auch können hierbei schon Kleinigkeiten, wie zum Beispiel das Rauchen der Lieblingszigarettenmarke eine Rolle spielen. Des Weiteren wurde versäumt, bei den Probanden den CO-Gehalt der Ausatemluft zu messen. Damit war vor Beginn der Studie nicht sichergestellt, dass der Proband abstinent war und dadurch auch für die Auswertung objektiv mit Craving reagieren konnte. Auch die Untersuchung zwischen Cue-Exposuregruppe und Vergleichsgruppe bezüglich QSU und VACS1-Werten über den gesamten Untersuchungszeitraum zeigte keine signifikanten Ergebnisse; allerdings gab es signifikante Effekte für VACS2-Werte. Es war außerdem eine signifikante Reduktion der QSU- und VACS2-Werte zwischen Sitzung 1 und Sitzung 2 zu erkennen. Das Gleiche gilt auch für Korrelationen zwischen den für das Craving relevanten Parametern FTND/QSU-/ VACS-Werten und den Nikotinspiegeln, die nur in Sitzung 1 und Sitzung 3 signifikante Beziehungen erkennen ließen. Außerdem könnte hier auch eine Rolle spielen, dass die Probanden mit zunehmender Dauer immer unkonzentrierter ihre Fragebögen ausfüllten. Die geringe Fallzahl der Probanden ist dafür verantwortlich, dass die Studie eine verminderte statistische Aussagekraft besitzt. Größere Teilnehmerkollektive wären notwendig gewesen, um die Fragestellung der vorliegenden Arbeit exakter zu klären. Außerdem wären längere Abstinenzzeiten vor Beginn der Studie sinnvoller, wie sich in vergleichbaren Studien erwiesen hat. Auch die Anwendung weiterer Stimuli hätten eventuell signifikantere Ergebnisse geliefert. Die Arbeit zeigt, dass sich der Begriff Craving nicht allgemein definieren / messen lässt und es auch in der Literatur diesbezüglich keine allgemein gültigen Aussagen, Messinstrumente und Beurteilungen gibt.In clinical research there are diverse results and opinions about the relation between craving and stimulus. Therefore it was the objective of this study to find out how the subjects reacted to the given stimulus (“a video showing someone smoking) after a nicotine abstinence of eight hours and after an application of 8 mg of nicotine. Moreover it was to be examined whether there is a relation between physiological reaction and the craving caused by the stimulus and whether the subjects of the cue exposure group show higher scores on the visual analog craving scale (VACS) and in the Questionnaire on Smoking Urges (QSU) than those of the control group. Another objective was to check whether there are significant correlations between the nicotine serum concentration of the subjects and the relevant parameters for craving measured by the Fagerström Test for Nicotine Dependence (FTND), QSU and VACS. Even though the subjects possessed similar qualities (age, sex, cigarettes smoked per day, duration of smoking (years), trial groups and FTND scores) no significant correlations were to be found between the nicotine serum concentration and the physiological parameters for craving (skin conduction level „SCL“ and pulse amplitude) during all expositions. There are several possible explanations for that: aside from the short period of abstinence prior to the application of the nicotine, another problem might have been that the subjects have not been isolated but were in the same room so that they could have influenced each other. Moreover it was hard to interpret the results of each subject because there were no neutral stimuli to compare with. The evaluation of the results did not show any significant correlations between the craving and the physiological reaction after the presentation of the stimulus „video“. The fact that the presented video did only appeal to a few subjects might be caused by not all people responding with craving after visual stimuli. Some subjects even need olfactory stimuli to develop craving. When presenting the stimulus even little things might be of importance like using the favorite cigarette brand of the subject. Besides no measurement of expiratory CO had taken place. Thus it was not secured that the subjects did not smoke before the examination and kept their abstinence of at least eight hours because then the subjects might not have been able to react properly that means to show craving. The examination of the cue exposure group and the control group concerning QSU and VACS1 scores over the period of the examination showed no significant results. Although there was a significant effect for the VACS2 scores. Moreover there was a significant reduction of the QSU and VACS2 scores between the first and the second exposition. The correlations between the relevant parameters for craving (FTND, QSU and VACS scores) and the nicotine serum concentrations were only significant during the first and the third exposition. One reason for that might have been that the subjects lost their concentration answering the questionnaires the longer the examination took. The small number of subjects in this study resulted in little statistical power. Greater numbers of subjects would have been necessary to examine the objective of this study with sufficient statistical power. Moreover a longer period of abstinence prior to the examination would have been more useful as other studies showed. Even the use of several other stimuli might have shown more significant results. This study shows that the term craving cannot be measured or defined in general and even in scientific literature there are no general statements, measurements and evaluations about craving