Die funktionelle Rolle der beiden Isoformen der NO-sensitiven Guanylyl Cyclase für die Langzeit-Potenzierung im Hippocampus der Maus

Die NO-sensitive Guanylylcyclase (NO-GC) wird von Stickstoffmonoxid (NO) aktiviert, was zu cGMP-Bildung führt. Es existieren zwei Isoformen der NO-GC (NO-GC1 und NO-GC2). Durch die Knock-out Mausmodelle konnte der Beitrag für die LTP-Induktion der beiden Isoformen genauer untersucht werden. In den WT-Mäusen konnte die LTP durch HFS induziert werden, hingegen zeigten die KO-Mäuse unter den gleichen Bedingungen keine LTP. Dies zeigt, dass beide NO-GC Isoformen an der LTP-Expression beteiligt sind. Während in den Rekonstituierungsexperimenten mit dem cGMP-Analogon konnte die LTP in den NO-GC2 KO-Mäusen im vergleichbar zu den NO-GC1 KO-Mäusen wiederhergestellt werden. Die PPR-Messung zeigte präsynaptische Veränderung der synaptischen Übertragung in den WT und NO-GC2 KO Mäusen, jedoch nicht in den NO-GC1 Mäusen. Eine unterschiedliche prä- und postsynaptische Lokalisation der beiden NO-GC Isoformen könnte die Erklärung für die veränderte synaptische Transmission in den KO-Mäusen sein

Complex Functional Posttraumatic Shoulder Reconstruction Using Shoulder Arthroplasty and a Pedicled Innervated Latissimus Dorsi Flap—A Case Report and Literature Review

Background The shoulder joint is one of the most freely movable joints in the human body and has therefore high importance for upper limb functionality. Several techniques have been developed to replace the glenohumeral joint including humeral hemiarthroplasty, anatomical total shoulder arthroplasty, and reverse total shoulder arthroplasty, depending on the underlying pathology. For the soft tissue reconstruction, the innervated latissimus dorsi musculocutaneous flap is a reliable solution flap in shoulder and arm reconstruction. Case presentation We present the case of a 16‐year‐old male patient with a complete destruction of the shoulder joint and soft tissues after ballistic trauma. We performed the reconstruction of the shoulder joint using a humeral hemiarthroplasty with a mesh fixation to the remaining glenoid. The soft tissue coverage and the restoration of the deltoid muscle function were insured with a pedicled innervated latissimus dorsi musculocutaneous flap. One year postoperatively, the patient showed a good function of the shoulder joint with an excellent aesthetical result and no pain. Conclusion The pedicled latissimus dorsi musculocutaneous flap can safely restore the shoulder function, while the humeral hemiarthroplasty with mesh fixation can be a reliable solution for the reconstruction of a completely destructed shoulder joint

Thumb reconstruction after radical tumor resection using free osteocutaneous lateral arm flap with secondary humerus fracture: A case report

Introduction Malignant diseases with infiltration of bony structures in the area of the phalanges or metacarpals require either amputation or complex reconstruction. The decision for reconstruction means to restore length, mobility, sensibility, stability as well as aesthetics. Methods We present a case of complex first ray reconstruction of the left hand using a free osteocutaneous lateral arm flap from the ipsilateral side. The reconstruction was performed after radical resection of an exulcerated squamous cell carcinoma, including the first metacarpal bone, trapezium, partial trapezoid and distal scaphoid as well as partial resection of the extensor pollicis longus, extensor pollicis brevis, abductor pollicis longus and flexor carpi radialis tendons. The osteosynthetic restoration was achieved distally by a double wire cerclage and a proximally by temporary K-wire suspension. Moreover, to reconstruct the extensor pollicis longus tendon the ipsilateral palmaris longus tendon was harvested and used. Postoperatively, a secondary humerus fracture occurred, which was initially attended by plate osteosynthesis. The fracture showed delayed healing, which was treated by re-plating and autologous cancellous bone. Results 12 months postoperatively, the patient showed an excellent outcome with length preservation and good range of motion, sensibility, stability and aesthetic of the thumb. Furthermore, the quarterly tumor aftercare showed no evidence of recurrence. Conclusion This case report showed that the free osteocutaneous lateral arm flap is a reliable solution for the reconstruction of the first ray with a great functional and aesthetic outcome. To prevent a secondary humerus fracture, a preventive plate osteosynthesis simultaneous with the osteocutaneous flap elevation should be considered

Microbiological study of sternal osteomyelitis after median thoracotomy – a retrospective cohort study

Abstract Introduction Deep sternal wound infection is a rare but feared complication of median thoracotomies and is usually caused by microorganisms from the patient’s skin or mucous membranes, the external environment, or iatrogenic procedures. The most common involved pathogens are Staphylococcus aureus, Staphylococcus epidermidis and gram-negative bacteria. We aimed to evaluate the microbiological spectrum of deep sternal wound infections in our institution and to establish diagnostic and treatment algorithms. Methods We retrospectively evaluated the patients with deep sternal wound infections at our institution between March 2018 and December 2021. The inclusion criteria were the presence of deep sternal wound infection and complete sternal osteomyelitis. Eighty-seven patients could be included in the study. All patients received a radical sternectomy, with complete microbiological and histopathological analysis. Results In 20 patients (23%) the infection was caused by S. epidermidis, in 17 patients (19.54%) by S. aureus, in 3 patients (3.45%) by Enterococcus spp., in 14 patients (16.09%) by gram-negative bacteria, while in 14 patients (16.09%) no pathogen could be identified. In 19 patients (21,84%) the infection was polymicrobial. Two patients had a superimposed Candida spp. infection. Methicillin-resistant S. epidermidis was found in 25 cases (28,74%), while methicillin-resistant S. aureus was isolated in only three cases (3,45%). The average hospital stay for monomicrobial infections was 29.93 ± 13.69 days and for polymicrobial infections was 37.47 ± 19.18 (p = 0.03). Wound swabs and tissue biopsies were routinely harvested for microbiological examination. The increasing number of biopsies was associated with the isolation of a pathogen (4.24 ± 2.22 vs. 2.18 ± 1.6, p < 0,001). Likewise, the increasing number of wound swabs was also associated with the isolation of a pathogen (4.22 ± 3.34 vs. 2.40 ± 1.45, p = 0.011). The median duration of antibiotic treatment was 24.62 (4–90) days intravenous and 23.54 (4–70) days orally. The length of antibiotic treatment for monomicrobial infections was 22.68 ± 14.27 days intravenous and 44.75 ± 25.87 days in total and for polymicrobial infections was 31.65 ± 22.29 days intravenous (p = 0.05) and 61.29 ± 41.45 in total (p = 0.07). The antibiotic treatment duration in patients with methicillin-resistant Staphylococci as well as in patients who developed an infection relapse was not significantly longer. Conclusion S. epidermidis and S. aureus remain the main pathogen in deep sternal wound infections. The number of wound swabs and tissue biopsies correlates with accurate pathogen isolation. With radical surgical treatment, the role of prolonged antibiotic treatment remains unclear and should be evaluated in future prospective randomized studies

The impact of two radical sternectomy surgical techniques on the outcome of deep sternal wound infections

Abstract Background Deep sternal wound infection (DSWI) is a rare, yet devastating complication after cardiac surgery. While the surgical treatment always implies the soft tissue and bone debridement, there is little data about this procedure. The aim of our study was to evaluate the impact of the radical sternectomy on the outcome in patients with DSWI and to identify the risk factors which could influence the result. The surgical techniques of piecemeal sternectomy and the newly developed en bloc sternectomy were also evaluated. Methods The study was developed as a retrospective cohort study. 86 patients with DSWI who received a radical sternal resection at our institution between March 2018 and December 2021 were included. Results The average age of the cohort was 67.3 ± 7.4 years, and 23.3% of patients were female. The average length of stay trended shorter after en bloc sternectomy (median 26 days) compared to piecemeal sternectomy (37 days). There were no significant differences between the piecemeal and en bloc sternal resection techniques. Anticoagulant and antiplatelet drugs had no significant influence on bleeding and transfusion rates. Obese patients showed an increased risk for postoperative bleeding requiring reintervention. Transfusion of packed red blood cells was significantly associated with lower hemoglobin values before surgery and ASA Class 4 compared to ASA Class 3. The in-hospital mortality was 9.3%, with female sex and reintervention for bleeding as significant risk factors. Nine patients developed an infection relapse as a chronic fistula at the level of clavicula or ribs, with ASA Class 4 as a risk factor. Conclusion Radical sternectomy is a safe procedure to treat DSWI with compromised sternal bone. Both piecemeal and en bloc techniques ensure reliable results, while complications and mortality appear to be patient-related