Zur Verbesserung der gegenw?rtigen bakteriologischen Diagnostik von enteroh?morrhagischen Escherichia coli (EHEC) Stufenplan für klinische und epidemiologische Zwecke Stufenplan für klinische und epidemiologische Zwecke

Die Diagnostik einer EHEC-Infektion des Menschen, einer seit 1998 bundesweit meldepflichtigen Infektionskrankheit, ist gegenw?rtig nicht verbindlich geregelt. Dabei bestehen insbesondere zum Einsatz von genotypischen und ph?notypischen Screeningverfahren noch unterschiedliche Auffassungen. Es gilt als gesichert, dass sie auf der Basis der Shigatoxinogenit?t erfolgen müssen. Anhand von künstlich kontaminierten Stuhlproben und vier unterschiedlichen EHEC-Testst?mmen wurde mithilfe von Kulturmedien und ELISA-Kits ein zeit- und kostengünstiges Verfahren überprüft. Ziel war es, bereits einen Tag nach Proben-Eingang eine positive Verdachtsdiagnose vorliegen zu haben. Dieser ersten Stufe der EHEC-Diagnostik muss als zweiten Stufe zur Best?tigung der Verdachtsdiagnose die Isolierung des entsprechenden ?tiologischen Agens erfolgen (ggf. Speziallabor). Eine dritte Stufe der EHEC-Diagnostik umfasst die weitere Subdifferenzierung der Isolate durch die Genotypie, Lysotypie, die Virulenzmusterbestimmung, insbesondere für epidemiologische Zwecke, die in das Aufgabenspektrum des Nationalen Referenzzentrums für Salmonellen und andere Enteritiserreger fallen.     

Planning of mandibular reconstructions based on statistical shape models

Purpose

The reconstruction of large continuity defects of the mandible is a challenging task, especially when the shape of the missing part is not known prior to operation. Today, the surgical planning is based mainly on visual judgment and the individual skills and experience of the surgeons. The objective of the current study was to develop a computer-based method that is capable of proposing a reconstruction shape from a known residual mandible part.

Methods

The volumetric data derived from 60 CT scans of mandibles were used as the basis for the novel numerical procedure. To find a standardized representation of the mandible shapes, a mesh was elaborated that follows the course of anatomical structures with a specially developed topology of quadrilaterals. These standard meshes were transformed with defined mesh modifications toward each individual mandible surface to allow for further statistical evaluations. The data were used to capture the inter-individual shape variations that were considered as random field variations and mathematically evaluated with principal component analysis. With this information of the mandibular shape variations, an algorithm was developed that proposes shapes for reconstruction planning based on given residual mandible geometry parts.

Results

The accuracy of the novel method was evaluated on six different virtually defined continuity defects that were each created on three mandibles that were not part of the initial database. Virtual reconstructions showed sufficient accuracy of the algorithm for the planning of surgical reconstructions, with average deviations toward the actual geometry of \(1.82 \pm 0.11\) mm for small missing parts and 5 mm for large hemi-lateral defects.

Conclusions

The presented algorithm may be a valuable tool for the planning of mandibular reconstructions. The proposed shapes can be used as templates for computer-aided manufacturing, e.g., with 3D printing devices that use biocompatible materials.

     

Clinical,angiographic and cardiovascular magnetic resonance findings in consecutive patients with Takotsubo cardiomyopathy

BACKGROUND: The aim was to assess clinical, angiographic and cardiovascular magnetic resonance (CMR) findings in patients with Takotsubo cardiomyopathy. METHODS: Between 2003 and 2007, 20 consecutive patients admitted to our hospital with suspected acute myocardial infarction and presenting with apical ballooning in the left ventricular (LV) angiogram in the absence of a significant coronary artery disease, were included in the study. Echocardiography and CMR was performed in all patients. RESULTS: The mean age of patients with Takotsubo cardiomyopathy was 62 +/- 8 years (range 43-78 years). Eighteen (90%) were female. Clinical presentations included chest pain (95%) and cardiogenic shock (5%). The mean angiographic LV ejection fraction on admission was 45% +/- 9% (range 26%-60%) and resolved rapidly in all cases. Mean time delay between presentation CMR was 2 +/- 1 days (range 1-6 days). Mean ejection fraction was 51% +/- 15% (range 25%-81%). While 19 (95%) patients showed no evidence of late enhancement or signs of myocarditis in the CMR, 1 (5%) patient who was resuscitated showed hyperenhancement confined to the apex. CONCLUSION: In patients showing the clinical picture of an acute myocardial syndrome and angiographic picture of a TakoTsubo cardiomyopathy, CMR might be helpful in confirming the diagnosis through the exclusion of other causes for the acute LV dysfunction.     

Dendritic cells under influence of mouse cytomegalovirus have a physiologic dual role: to initiate and to restrict T cell activation

The aim of this study is to analyze the dynamics of the mouse cytomegalovirus (MCMV)-dendritic cell (DC) interaction. Immature and mature DCs derived from the mouse stem cell line factor-dependent cell Paterson mixed potential were infected with a recombinant MCMV expressing green fluorescent protein. Infection of immature DCs resulted in DC activation and virus production, both of which may contribute to viral dissemination. The infection of mature DCs was nonproductive and was restricted to immediate-early and early viral protein expression. During early stages of MCMV infection, mature DCs up-regulated major histocompatibility complex (MHC) and costimulatory molecules and activated autologous, but not allogeneic, naive T cells. At later times of MCMV infection, DCs prevented T cell activation by down-regulation of MHC and costimulatory molecules. Thus, DCs under the influence of MCMV have a physiologic dual role: to initiate and to restrict T cell activation. The lack of immunostimulation in allogeneic settings may explain the increased risk of MCMV morbidity after allogeneic transplantation.     

Direct visualization of coronary sinus ostium and branches with a flexible steerable fiberoptic infrared endoscope.

BACKGROUND: Placement of electrophysiology catheters and pacing leads in the coronary sinus is challenging in some patients, particularly those with dilated cardiomyopathy. We hypothesized that cannulation of the coronary sinus and its branches can be facilitated by direct visualization. This study reports our experience with navigation into and within the coronary sinus in a closed-chest animal preparation, using a flexible steerable fiberoptic infrared endoscope that allows visualization through flowing blood. OBJECTIVES: The purpose of this study was to assess the feasibility of direct visualization of endocardial structures through infrared endoscopy. METHODS: Internal jugular venous access was obtained in 10 healthy mongrel dogs (weight 35-45 kg). The infrared endoscope (2900 fiber imaging bundle, wavelength 1,620 nm, frame rate 10-30/s, 320 x 256 pixels) was advanced to the coronary sinus ostium and branches by direct visualization of anatomic landmarks, such as the tricuspid valve and inferior vena cava. Localization was confirmed by fluoroscopy, contrast injection, and pathologic examination. RESULTS: Structures such as the tricuspid valve and inferior vena cava were visualized at distances of 1 to 2 cm, allowing successful coronary sinus identification and engagement in all 10 dogs. Coronary sinus branch images closely resembled pathologic findings. CONCLUSION: Direct visualization of the coronary sinus ostium and branches is possible through infrared endoscopy. This technique likely will facilitate coronary sinus engagement and navigation for pacing lead and catheter placement.     

The ALT chimera flap: expanding the indications

The anterolateral thigh (ALT) perforator flap has become one of the major workhorses in reconstructive surgery because of its reliability and low donor site morbidity. However, the indications for this flap are limited when underlying cavities need to be filled or a separate bulk of muscular tissue is needed. To overcome these setbacks, an adipocutaneous-muscle ALT chimera flap with a muscular appendage supplied by a separate branchlet of the perforator pedicle is a useful tool. This work describes the surgical procedure and shows the results of 15 patients with a chimera ALT flap in a series of 88 patients with ALT flaps. Patients with defects after trauma (n?=?8), cavities after tumour resection (n?=?5) or patients with fasciitis (n?=?2) were considered for an ALT chimera flap. A separate vessel for the muscular appendage was found in all 15 cases and the chimera flap could be raised successfully. Filling the underlying cavities and smooth cutaneous defect coverage was possible in all cases. No flap failure was seen (failure rate 5.6% in the whole series), but two patients required microsurgical revisions. Other complications were similar to regular ALT flap procedures. Only one patient developed a complication possibly related to including the muscular component (donor site haematoma). A separate muscular appendage added to the classical ALT flap allows an expansion of the indications of a flap well known for its low complication rate and versatility in reconstructive surgery.     

Noninvasive evaluation of renal allograft fibrosis by transient elastography – a pilot study

Chronic allograft injury (CAI) is the most common cause of graft failure after the first year of transplantation. To date, only protocol biopsies can reveal subclinical disease. Transient elastography (TE) is a novel noninvasive technique that has demonstrated high reliability in the assessment of liver fibrosis. This study evaluates the feasibility of TE for the assessment of renal allograft fibrosis. Fifty‐seven patients underwent TE by the FibroScan® device. Biopsies were performed in 20 patients. Measurement of parenchymal stiffness by TE was successful in 55 of 57 patients (96.5%). Stiffness was significantly correlated to the extent of interstitial fibrosis (Pearson r: 0.67, P: 0.002, R²: 0.45) and inversely related to estimated glomerular filtration rate (eGFR) (Pearson r: ?0.47, P: 0.0003, R²: 0.22). Stiffness values of patients with an eGFR >50 ml/min were significantly lower than in patients with an eGFR ≤50 ml/min (22.2 ± 11.0 vs. 37.1 ± 14.2 kPa, P: 0.0005). The stiffness values of CAI Banff grades 0–1 differed significantly from grade 2 (P: 0.008) and grade 3 (P: 0.046). Parenchymal stiffness measured by TE reflects interstitial fibrosis in kidney allografts. A longitudinal assessment of parenchymal stiffness might be a powerful tool to identify patients with CAI who benefit from biopsy and consequent adaptation of the immunosuppressive regime.     

Evolving experience with prevention and treatment of splenic artery syndrome after orthotopic liver transplantation

Impaired hepatic arterial perfusion after orthotopic liver transplantation (OLT) may lead to ischemic biliary tract lesions and graft‐loss. Hampered hepatic arterial blood flow is observed in patients with hypersplenism, often described as arterial steal syndrome (ASS). However, arterial and portal perfusions are directly linked via the hepatic arterial buffer response (HABR). Recently, the term ‘splenic artery syndrome’ (SAS) was coined to describe the effect of portal hyperperfusion leading to diminished hepatic arterial blood flow. We retrospectively analyzed 650 transplantations in 585 patients. According to preoperative imaging, 78 patients underwent prophylactic intraoperative ligation of the splenic artery. In case of postoperative SAS, coil‐embolization of the splenic artery was performed. After exclusion of 14 2nd and 3rd retransplantations and 83 procedures with arterial interposition grafts, SAS was diagnosed in 28 of 553 transplantations (5.1%). Twenty‐six patients were treated with coil‐embolization, leading to improved liver function, but requiring postinterventional splenectomy in two patients. Additionally, two patients with SAS underwent splenectomy or retransplantation without preceding embolization. Prophylactic ligation could not prevent SAS entirely (n = 2), but resulted in a significantly lower rate of complications than postoperative coil‐embolization. We recommend prophylactic ligation of the splenic artery for patients at risk of developing SAS. Post‐transplant coil‐embolization of the splenic artery corrected hemodynamic changes of SAS, but was associated with a significant morbidity.     

Approach-related lesions of the sympathetic chain in anterior correction and instrumentation of idiopathic scoliosis

During anterior scoliosis instrumentation with a dual-rod system, the vertebrae are dissected anterolaterally. After surgery, some patients report a change in temperature perception and perspiration in the lower extremities. Sympathetic lesions might be an explanation for this. The aim of this clinical study was to investigate sympathetic function after anterior scoliosis instrumentation. A total of 24 female patients with idiopathic scoliosis (mean age at follow-up, 23.8 years) who had undergone anterior instrumentation on average 6.6 years earlier were included. Due to the suspected relevance of the sympathetic L2 ganglion, two groups were created: a T12 group, in which instrumentation down to T12 was carried out (n = 12), and an L3 group, in which instrumentation down to L3 was done (n = 12). Sympathetic function was assessed by measuring skin temperature at the back of the foot, a plantar ninhydrin sweat test and sympathetic skin responses (SSRs) following electrical stimulation. The side on which the surgical approach was carried out was compared with the contralateral, control side. Health-related quality of life was investigated using the Scoliosis Research Society SRS-22 patient questionnaire. In the T12 group, mean temperatures of 29.6°C on the side of the approach versus 29.5°C on the control side were measured (P > 0.05); in the L3 group, the mean temperatures were 33.2°C on the approach side versus 30.5°C on the control side (P = 0.001). A significant difference between the T12 group and the L3 group (P < 0.001) was observed on the approach side, but not on the control side (P = 0.15). The ninhydrin sweat test showed reduced perspiration in 11 of 12 patients in the L3 group on the approach side in comparison with the control side (P = 0.002). In the T12 group, no significant differences were noted between the left and right feet. SSRs differed significantly between the two groups (P = 0.005). They were detected in all nine analyzable patients in the T12 group on both sides. In the L3 group, they were found on the approach side only in 4 of 11 analyzable patients versus 11 patients on the control side. The results of the SRS-22 questionnaire did not show any significant differences between the two groups. In conclusion, anterior scoliosis instrumentation with a dual-rod system including vertebrae down to L3 regularly leads to lesions in the sympathetic trunk. These are detectable with an increase in temperature, reduced perspiration and reduced SSRs. The caudal level of instrumentation (T12 vs. L3) has an impact on the extent of impairment, supporting the suspected importance of the L2 ganglion. The clinical outcome does not seem to be significantly limited by sympathetic trunk lesions.