Hirnfunktionelle Korrelate bei Zwangsstörungen: Untersuchung mit ereigniskorrelierten Potentialen

Die Zwangsstörung wurde lange Zeit als eine relativ seltene Krankheit angesehen. Erst durch neuere epidemiologische Untersuchungen zeigte sich, dass sie die vierthäufigste neuro-psychiatrische Erkrankung darstellt. Das Besondere an ihr ist, dass sie im Gegensatz zu anderen neuro-psychiatrischen Erkrankungen, mit einer hirnelektrischen Überaktivität assoziiert sein soll. Vor allem dem überaktivierten orbito-frontalen Kortex wird in zahlreichen Studien eine wichtige Rolle bei der Ätiopathogenese der Zwangsstörung beigemessen. Da die Literatur dazu hauptsächlich auf bildgebende Untersuchungsverfahren mit mangelhafter zeitlicher Auflösung basiert, erscheint es wichtig, die Validität der Erklärungsmodelle zur Entstehung der Zwangsstörung mit einem Analyseverfahren zu überprüfen, das diesen Nachteil nicht hat. Unabhängig davon existieren Befunde, dass bei der Zwangssymptomatik im Ableitungskanal Pz, verkürzte Latenzen bei akustischen P300-Oddball-Paradigmen vorzufinden sind, welche ebenfalls Ausdruck dieser gesteigerten zerebralen Aktivität sein sollen. Die Ergebnisse zu den analogen P300-Amplituden sind dagegen weit weniger konsistent, was auf die recht kleinen Untersuchungskollektive bisheriger Studien zurückzuführen ist. Vorteilhaft an unserem Analyseverfahren ist, dass zu den zerebralen Generatoren der P300 auch Hirnareale zählen, die für die Entstehung und Aufrechterhaltung der Zwangssymptomatik verantwortlich gemacht werden. Dazu gehört insbesondere der orbito-frontale Kortex. Das Ziel dieser Arbeit war somit die Klärung, ob nicht nur die P300-Latenz bei Zwangsstörungen eine Veränderung, im Sinne einer Verkürzung, zeigt, sondern ob auch die P300-Amplitude sich anders darstellt. Erhöhte Amplituden bei Patienten mit Zwangsstörungen wären besser mit der in der Literatur beschriebenen Hyperaktivität vereinbar. Weiterhin gingen wir der Frage nach, in welchen Hirnregionen diese Veränderungen lokalisiert seien und ob eine Hypo- oder Hyperaktivität damit verbunden wäre. Wir erwarteten eine Bestätigung der postulierten Überaktivierung im orbito-frontalen Kortex. Als nächstes wollten wir mögliche Therapieeffekte auf die P300 bzw. auf die zerebrale Hyperaktivität prüfen. Eine Angleichung der hirnfunktionellen Veränderungen an den gesunden Normalzustand nach einer Kombinationstherapie aus Sertralin und multimodaler Verhaltenstherapie wurde angenommen. Letztendlich sollte noch die Frage geklärt werden, ob diese hirnfunktionellen Abnormitäten bei Patienten mit Zwangsstörungen mit der Schwere der Erkrankung korrelieren. Wir untersuchten 71 unbehandelte Patienten mit Zwangsstörungen und 71 gesunden Personen mit einem akustischen P300-Oddball-Paradigma und zeichneten dabei die ereigniskorrelierten Potentiale mit 31 Elektroden auf. Wie bereits angenommen, konnte bei den Patienten mit Zwangsstörungen eine erhöhte P300-Amplitude beobachtet werde. Die P300-Latenz zeigte im Vergleich zu den gesunden Kontrollen nur eine deskriptive Verkürzung. Die Stromdichteverteilung im Talairach-Raum wurde mit der Low Resolution Electromagnetic Tomography (LORETA) durchgeführt. Wir konnten im Zeitintervall der P300 (240 - 580 ms) vier Hirnareale, alle in der linken Hirnhälfte lokalisiert, mit einer signifikant erhöhten Überaktivität bei Patienten mit Zwangsstörungen identifizieren. So zeigten neben dem inferio-temporalen Kortex des Temporallappens, dem inferio-parietalen Kortex des Parietallappens und dem mittleren Gyrus frontalis, vor allem der orbito-frontale Kortex des Frontallappens, signifikant höhere elektrische Aktivierung. Die von uns aufgestellte Hypothese einer orbito-frontalen Hyperaktivität erwies sich also als richtig. Der Einfluss der 10-wöchigen Kombinationstherapie wurde bei 43 von den ursprünglichen 71 Patienten mit Zwangsstörungen untersucht. Nach der Kombinationstherapie normalisierte sich die Überaktivität lediglich im mittleren Gyrus frontalis. Auf der Potentialbasis wiesen hingegen die P300-Amplituden und -Latenzen keine signifikanten Veränderungen auf. In der abschließenden Untersuchung ließ sich kein Zusammenhang zwischen der Psychopathologie (Y-BOCS) und den hirnfunktionellen Abnormitäten bei Zwangsstörungen festgestellen. Die Ergebnisse der vorliegenden Studie sind größtenteils konsistent mit der aktuellen Literatur zur Zwangssymptomatik. Es ist die einzige Arbeit zur Untersuchung der zerebralen Aktivität bei Patienten mit Zwangsstörungen, die dafür einen linearen Lösungsansatz für das inverse EEG-Problems verwendete. Auch existieren nur wenige Studien, die eine vergleichbar große Anzahl an Patienten mit Zwangsstörungen analysiert haben. Dies gilt insbesondere für die Erkenntnisse aus der funktionelle Bildgebung (PET, fMRT, SPECT), die letztendlich den Hauptbeitrag zur Bildung der Hypothese einer zerebralen Hyperaktivität bei Zwangsstörungen leisteten. So wiesen PET- bzw. fMRT-Studien selten mehr 25 zu untersuchende Patienten auf. Die hier verwendete Stromdichte-Analyse bestätigt somit die Befunde aus der funktionellen Bildgebung (fMRT, SPECT, PET) mit ihrem mangelhaften zeitlichen Auflösungsvermögen, dass vor allem eine orbito-frontale Überaktivität die Zwangsstörung charakterisiert. Darüber hinaus konnte zum ersten Mal eine Verbindung zwischen den abnormen P300-Potentialwerten und der zerebralen Hyperaktivität bei Zwangsstörungen hergestellt worden. Auch konnte erstmalig eine Normalisierung der Überaktivität im Gyrus frontalis medius nach Therapie beobachtet werden

Doping in Sports, a Never-Ending Story ?

Through doping, we understand the use by athletes of substances prohibited by the anti-doping agencies in order to gain a competitive advantage. Since sport plays an important role in physical and mental education and in promoting international understanding and cooperation, the widespread use of doping products and methods has consequences not only on health of the athletes, but also upon the image of sport. Thus, doping in sports is forbidden for both ethical and medical reasons. Narcotics and analgesics, anabolic steroids, hormones, selective androgen receptor modulators are among the most frequently utilized substances. Although antidoping controls are becoming more rigorous, doping and, very importantly, masking doping methods are also advancing, and these are usually one step ahead of doping detection techniques. Depending on the sport practiced and the physical attributes it requires, the athletes will look for one or more of the following benefits of doping: recovering from an injury, increasing body recovery capacity after training, increasing muscle mass and strength, decreasing fat tissue, increasing endurance. Finally, when we look once again at a doping scandal, amazed at how much animosity against those caught can exist; the question is: is it really such a disaster as presented by the media or a silent truth under our eyes, but which many of us have refused to accept

Diabetic patients and postoperative complications in colorectal surgery

Diabetes mellitus is one of the most common comorbidities of patients undergoing surgery. Colorectal surgery is frequently associated with postoperative complications, and diabetic patients represent a population that presents a high risk of developing such complications. Understanding the interrelationships between neoplastic disease and diabetes, as well as the pathophysiological mechanisms underlying postoperative complications, are essential for effective therapeutic management. Genetic predispositions, alterations in the gut microbiota, inflammatory response, ischemic, thrombotic and infectious processes contribute significantly to the development of severe surgical complications, such as anastomotic fistulas. Postoperative ileus, characterized by gastrointestinal dysmotility, is common in diabetic patients due to neuropathic dysfunction and altered intestinal metabolism. In addition, diabetic patients are at increased risk of intestinal ischemia, requiring specific perioperative care. The strategies to avoid these complications assume an adequate surgical technique, a personalized anesthesia management, and last but not least, the best possible glycemic control. This article highlights the importance of a better understanding of the interaction between diabetes and postoperative complications, in order to obtain good results with an important impact on the patient\u27s health and well-being. This article highlights the importance of a better understanding of the interplay between diabetes and postoperative complications informs targeted interventions aimed at reducing morbidity and improving patient well-being

Nerve compression due to benign tumors or ganglion cysts in the upper limb – case series

Tumor nerve compressions in the upper limb are relatively rare, usually involving ganglion cysts and benign tumors. We present a case series of five patients with peripheral nerve compression in the upper limb due to tumor or cystic masses- ulnar nerve compression in the Guyon’s tunnel due to a ganglion cyst, large median nerve schwannoma compressing anterior interosseous nerve and median nerve, voluminous lipoma compressing median nerve in the proximal forearm, superficial branch of radial nerve compression by a synovial cyst and elbow region lipoma compressing radial nerve. In the beginning, those benign lesions are asymptomatic but, as they continue to grow adjacent to a peripheral nerve clinical manifestations appear progressively as compressive neuropathies. After a preoperative imagistic analysis, tumor resection with careful dissection, in order to preserve the neurovascular structures, is the elective surgical procedure in order to obtain an optimal functional recovery

High Performance Shunt Active Power Filter: Design Consideration and Experimental Evaluation

The paper presents an active power filter with high performance, achieved by the authors. To obtain these performances some contributions were brought, both in the power part and in the control part, those are highlighted. First, some design considerations of interface filter are done. Next, the experimental setup is presented and a lot of experimental determinations for different conditions of voltage and load are shown. These and some indices calculated show that, indeed, the achieved filtering platform has very good performances

Optimization of Manufacturing Processes by Reducing the Costs of Tools and Equipment on Hydraulically Operated High-Pressure Technological Lines

Most technological manufacturing lines include hydraulically operated stationary tools, devices and equipment. During a manufacturing cycle, there are phases, usually short, in which part of the hydraulic cylinders of the drive systems concerned, with small gauges and displacement speeds, have to generate / maintain high clamping or pressing forces, which implies functioning at high working pressures. The solution for such cylinders is to use modular hydraulic pumping units comprising: oil tank; low-pressure electric pump; hydraulic directional valve for starting, stopping and changing the direction of displacement of the cylinder; electric pump pressure control valve; pressure filter; return filter; oscillating hydraulic pressure intensifier (minibooster mounted directly on the cylinder). Such pumping units, which consume low pressure (in the primary side of the minibooster) to generate high pressure (in the secondary side of the minibooster), are cost-effective when it comes to the procurement of components, installing them, the space required for installation, and their maintenance, too. The classic applications of using them are for achieving and maintaining high pressure values, either in volumes of closed spaces (endurance tests on pipes and tanks), or at the active stroke end of hydraulic cylinders (hydraulic presses). The authors demonstrate, on a laboratory test bench, the following: - The range of applications of such pumping units can be extended in a third direction, namely for actuation of hydraulic cylinders with low gauge / speeds and constant high load (high working pressure) over the entire stroke; - The uniformity of displacement of these cylinders with load over the entire stroke, fed and actuated by such pumping units, is weakly affected by the pulsating mode of operation of the hydraulic pressure intensifier

An SDR-Based Satellite Gateway for Internet of Remote Things (IoRT) Applications

Internet-of-Things (IoT) represents a breakthrough for the current ICT market. In many IoT applications, sensors and actuators are distributed over very wide areas, sometimes not reached by terrestrial networks. In such scenarios, the satellite plays a significant role. In this paper, a Software-Defined Radio (SDR) - based satellite gateway for Internet-of-Remote-Things (IoRT) is proposed. The use of SDR allows to decrease equipment cost and provides higher flexibility. The proposed architecture has been implemented by using a standalone SDR platform and Commercial Off-The-Shelf (COTS) modules for covering the main terrestrial IoT standards. Extensive proof-of-concept results are presented and discussed. Uplink and downlink tests showed the correct functionality implementation and transmitted signal generation, while the integration tests allowed to assess the reliability of the end-to-end information processing. Reconfigurability tests confirmed the capability of the gateway of dynamically updating in real-time its protocol settings. The overall test results showed the validity of the proposed SDR-based gateway for IoRT applications

An exploratory study on isochoric supercooling preservation of the pig liver

This study was motivated by the increasing interest in finding ways to preserve organs in a supercooled state for transplantation. Previous research with small volumes suggests that the isochoric (constant volume) thermodynamic state enhances the stability of supercooled solutions.The primary objective of this study was to investigate the feasibility of storing a large organ, such as the pig liver, in a metastable isochoric supercooled state for clinically relevant durations. To achieve this, we designed a new isochoric technology that employs a system consisting of two domains separated by an interior boundary that can transfer heat and pressure, but not mass. The liver is preserved in one of these domains in a solution with an intracellular composition, which is in osmotic equilibrium with the liver. Pressure is used to monitor the thermodynamic state of the isochoric chamber. In this feasibility study, two pig livers were preserved in the device in an isochoric supercooled state at -2°C. The experiments were terminated voluntarily, one after 24 h and the other after 48 h of supercooling preservation. Pressure measurements indicated that the livers did not freeze during the isochoric supercooling preservation. This is the first proof that organs as large as the pig liver can remain supercooled for extended periods of time in an isotonic solution in an isochoric system, despite an increased probability of ice nucleation with larger volumes. To serve as controls and to test the ability of pressure monitoring to detect freezing in the isochoric chamber, an experiment was designed in which two pig livers were frozen at -2°C for 24 h and the pressure monitored. Histological examination with H&E stains revealed that the supercooled liver maintained a normal appearance, even after 48 h of supercooling, while tissues in livers frozen to -2°C were severely disrupted by freezing after 24 h

An exploratory study on isochoric supercooling preservation of the pig liver

This study was motivated by the increasing interest in finding ways to preserve organs in a supercooled state for transplantation. Previous research with small volumes suggests that the isochoric (constant volume) thermodynamic state enhances the stability of supercooled solutions. The primary objective of this study was to investigate the feasibility of storing a large organ, such as the pig liver, in a metastable isochoric supercooled state for clinically relevant durations. To achieve this, we designed a new isochoric technology that employs a system consisting of two domains separated by an interior boundary that can transfer heat and pressure, but not mass. The liver is preserved in one of these domains in a solution with an intracellular composition, which is in osmotic equilibrium with the liver. Pressure is used to monitor the thermodynamic state of the isochoric chamber. In this feasibility study, two pig livers were preserved in the device in an isochoric supercooled state at -2°C. The experiments were terminated voluntarily, one after 24 h and the other after 48 h of supercooling preservation. Pressure measurements indicated that the livers did not freeze during the isochoric supercooling preservation. This is the first proof that organs as large as the pig liver can remain supercooled for extended periods of time in an isotonic solution in an isochoric system, despite an increased probability of ice nucleation with larger volumes. To serve as controls and to test the ability of pressure monitoring to detect freezing in the isochoric chamber, an experiment was designed in which two pig livers were frozen at -2°C for 24 h and the pressure monitored. Histological examination with H&E stains revealed that the supercooled liver maintained a normal appearance, even after 48 h of supercooling, while tissues in livers frozen to -2°C were severely disrupted by freezing after 24 h