Biomedical subjects

Dirk Troitzsch

Publications and source records attributed to Dirk Troitzsch.

5 recordsLinked to original sources

PubMed2004

Detection of anti-hsp70 immunoglobulin G antibodies indicates better outcome in coronary artery bypass grafting patients suffering from severe preoperative angina.

BACKGROUND: Recent findings indicate that molecular chaperones actively participate in myocardial cytoprotection. Moreover, ischemic tolerance can be induced in humans by brief ischemic events. Therefore, we investigated patients with severe angina attacks before coronary artery bypass grafting. We focused on appearance of anti-hsp70 antibodies as an immunologic response to heat shock protein induction by ischemia followed up by hemodynamic measurements perioperatively. We correlated these clinical findings with the presence of antibodies against hsp70 and the antioxidative capacity of patients' sera. METHODS: Thirty-five consecutive patients with coronary artery disease scheduled for coronary artery bypass grafting were included. Seventeen patients had severe angina, and 18 patients suffered from chronic stable angina preoperatively. In the patients' sera, antibodies against hsp70 were detected by enzyme-linked immunosorbent assay, and antioxidative capacity was detected using the chromogen assay. Cardiac output and pulmonary capillary wedge pressure were measured using a thermodilution catheter. We also evaluated C-reactive protein and creatine kinase MB isoenzyme, and performed a conventional leukocyte count. RESULTS: The sera of the 17 patients with severe angina attacks before surgery contained antibodies against hsp70 and a low antioxidative capacity. The interval between a severe angina attack and anti-hsp70 antibody titer are inversely correlated. These patients had better cardiac output and lower pulmonary capillary wedge pressure values after surgery. CONCLUSIONS: Severe angina before cardiac surgery coincided with an improved outcome as measured by hemodynamic variables as compared with chronic stable angina. This finding correlated significantly with a low antioxidative capacity and the presence of antibodies against hsp70. These pathophysiologic mechanisms might therefore play a role in myocardial protection.

Aged↗

PubMed2004

Ossifying fibroma of the skull: interactive image-guided minimally invasive localization and resection.

Ossifying fibroma is a benign fibro-osseous tumor commonly affecting the craniofacial bones. It is considered to be a locally aggressive and quickly expansible bone lesion. Because of its aggressive nature and high recurrence rate, early detection and complete surgical removal are essential. Usually, these lesions are excised extensively by craniectomy, and bone loss is reconstructed by cranioplasty using acrylic resin or titanium implants. Alternatively, in the management of skull-ossifying fibroma, an image-guided technique using surgical navigation may provide precise information about localization, enabling complete removal, thereby operating with minimal exposure and within narrow resection borders and avoiding significant bone deformity. A 39-year-old male patient with a history of renal cell carcinoma was admitted to our hospital because a radionuclide scintigraphic bone scan revealed increased uptake in a small area located at the left lateral skull bone. The high-resolution computed tomography scan showed that the lesion was located inside the diploe, destroying the inner table of the calvarium. The patient underwent minimally invasive bone lesion removal using an interactive image-guided approach. Complete resection of the neoplastic lesion was achieved. The histopathological examination revealed an ossifying fibroma. The postoperative course was uneventful, and the patient was discharged 3 days after intervention. To date, there has been no evidence of local recurrence. Interactive multimodal planning and intraoperative image guidance offer an interesting approach for biopsy and minimally invasive removal of small ossifying fibroma lesions of the skull, especially in less accessible locations.

Adult↗

PubMed2004

Temporary intermaxillary fixation using individualized acrylic splints permits image-data-based surgery of the lower jaw and oropharynx.

OBJECTIVES/HYPOTHESIS: Image-data-based surgical navigation is used as a helpful device in the operating room to localize critical structures with a high degree of accuracy. It also enables physicians to plan therapeutic performance. Because it relies on preoperatively acquired computed tomography (CT) or magnetic resonance imaging (MRI) data, there is restricted access for navigation of surgical instruments in areas that show motion uncorrelated with radiologic data. Thus, in the case of moveable structures, for example the lower jaw, navigational procedures could not yet be applied. STUDY DESIGN: We introduce a new technique using individualized intermaxillary splints that fix the mandible in a reproducible aboccluded position at the time of image-data acquisition and surgery. METHODS: Different manufacturing processes were investigated. The feasibility of uni- and bilateral intermaxillary splints was studied under clinical conditions in four patients during different procedures in the mandibular and oropharyngeal regions. RESULTS: The manufacturing of the splints showed was easily performed in a short time. With bilateral fixation, there was a high anatomic target precision of 1.6 to 2.3 mm. CONCLUSIONS: The use of bilateral intermaxillary splints that fix the patient's mandible in a reproducible aboccluded position permits an image-data-based navigated surgical approach to the oropharyngeal and mandibular regions.

Humans↗

PubMed2003

Release patterns of astrocytic and neuronal biochemical markers in serum during and after experimental settings of cardiac surgery.

OBJECTIVE: Brain injury and altered psychomotor development in infants, children and adults after cardiac surgery using cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) is still a matter of concern. Early diagnosis and identification of brain injury that has occurred or is ongoing by measurement of biochemical markers in serum may have diagnostic and prognostic value. The aim of the experimental studies in an animal model was therefore to investigate the release patterns of astroglial and neuronal markers in serum and to determine the morphological and immunohistochemical changes in the brain of animals undergoing similar perfusion conditions of CPB and a period of DHCA. METHODS: Fourteen New Zealand rabbits, (weight, 3.1 +/- 0.25 kg) were anesthetized, intubated and mechanically ventilated. Four animals were sham operated and served as controls. After median sternotomy the animals were connected to CPB by cannulation of the aorta and right atrium. Full flow CPB (200-250 ml/kg/min) was initiated to achieve homogeneous systemic cooling. Circulatory arrest of 60 minutes was induced when rectal and nasopharyngeal temperature of 14 degrees C was achieved. After rewarmed reperfusion and establishment of stable cardiac ejection the animals were weaned from CPB and monitored for 6 hours. Then the animals were killed, the brain was immediately removed and cut in standardized sections. These were fixated, embedded in paraffin and stained for further quantitative histological studies. In the brain astrocyte reactivity for S-100B was assessed immunocytochemically (DPC Immustain Los Angeles, USA). Monoclonal mouse anti-human neurospecific enolase (NSE) antibody was used for the localization of NSE in the fixed and paraffin embedded brain (NSE-DAKO, H14). The concentrations of S-100B protein and neurospecific enolase (NSE) in the serum were analyzed using a commercially available immunoluminometric assay (LIA-mat, Sangtec 100, Byk-Sangtec). Immunospecific monoclonal anti-parvalbumin antibody was used for the detection of parvalbumin in the brain. Serum concentrations of parvalbumin were analyzed using a newly developed ELISA method. RESULTS: In all experimental animals a significant increase of the serum concentration of the astroglial protein S-100B was found immediately after reperfusion and the termination of CPB. In contrast the serum levels of the neuronal proteins parvalbumin and NSE were not increased, but rather decreased. Light microscopy and electron microscopy revealed perivascular astrocytic swelling and minor neuronal cell injury. In comparison to the sham operated animals, increased immunohistochemical staining of S-100B was found. This increased reactivity of S100B antibody was found in the astrocytic processes with immediate connection to the perivascular space and around the perivascular oedema. The immunocytochemical stainings for NSE and parvalbumin in the neuronal cells was not different from that of sham-operated animals and indicated well preserved neurons.

Animals↗

PubMedDate not supplied

Navigation-assisted sclerotherapy of orbital venolymphatic malformation: a new guidance technique for percutaneous treatment of low-flow vascular malformations.

Percutaneous sclerotherapy of orbital low-flow vascular malformations requires precise procedural guidance. For the treatment of a patient with an orbital venolymphatic malformation, we sought to optimize guidance by combining navigation assistance for needle placement with intralesional contrast medium injection for assessment of venous drainage. By using a surgical navigation system (Vector Vision, BrainLAB, Munich, Germany), multiplanar target lesion visualization was performed after fusion of CT and MR imaging data, which allowed precise puncture planning.

Adult↗