Leveraging Parameter Dependencies in High-Field Asymmetric Waveform Ion-Mobility Spectrometry and Size Exclusion Chromatography for Proteome-wide Cross-Linking Mass Spectrometry

Ion-mobility spectrometry shows great promise to tackle analytically challenging research questions by adding another separation dimension to liquid chromatography-mass spectrometry. The understanding of how analyte properties influence ion mobility has increased through recent studies, but no clear rationale for the design of customized experimental settings has emerged. Here, we leverage machine learning to deepen our understanding of field asymmetric waveform ion-mobility spectrometry for the analysis of cross-linked peptides. Knowing that predominantly m/z and then the size and charge state of an analyte influence the separation, we found ideal compensation voltages correlating with the size exclusion chromatography fraction number. The effect of this relationship on the analytical depth can be substantial as exploiting it allowed us to almost double unique residue pair detections in a proteome-wide cross-linking experiment. Other applications involving liquid- and gas-phase separation may also benefit from considering such parameter dependencies.

[Non-invasive diagnosis of pulmonary hypertension: ESC/ERS Guidelines with commentary of the Cologne Consensus Conference 2010]

The 2009 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension have been adopted for Germany. The guidelines contain detailed recommendations for the diagnosis of pulmonary hypertension. However, the practical implementation of the European Guidelines in Germany requires the consideration of several country-specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update y appears necessary. In June 2010, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to non-invasive diagnosis of PH. This commentary summarizes the results and recommendations of the working group on treatment of PAH.

Treatment of acute embolic occlusions of the subclavian and axillary arteries using a rotational thrombectomy device

Acute embolic or local thrombotic ischaemia of the upper limbs can be treated by embolectomy or by endovascular techniques. We report here on the endovascular thrombectomy of acute embolic occlusions of subclavian and axillary arteries in two patients using a rotational thrombectomy device and give an overview about the actual literature. Two female patients, each with a history of multivessel coronary disease and intermittent atrial fibrillation, complained of sudden onset of pain at rest and paleness of the left and right arm, respectively. Duplex ultrasound showed a localized embolic occlusion of the left subclavian artery and the bifurcation of the brachial artery in the first patient and a localized embolic occlusion of the distal right subclavian and axillary artery in the second patient. In the first patient, the left subclavian artery was reopened using a 8F-Rotarex device via the femoral access, while the bifurcation of the brachial artery was reopened by local thrombolysis using 25 mg rt-PA because of the insufficient length of the thrombectomy device of 80 cm. In the second patient, the right subclavian and axillary arteries were reopened using a 6F-Rotarex device. Follow-up examinations before discharge and after 6 months showed normalized perfusion of the arms of both patients.

[First experiences with a 6F-sheath compatible self-expanding nitinol stent]

BACKGROUND

To evaluate the efficacy, safety and limitation of a new 6F-compatible nitinol stent (Dynalink(TM).

MATERIAL AND METHODS

We treated 50 patients (17 women, 33 men, mean age 72 +/- 8 years) by implanting 80 Dynalink(TM)-stents into 75 vessels during a 6-month period. Target lesions were: iliac artery: 25, femoral artery: 31, popliteal artery: 16, femoro-popliteal bypass: 5, subclavian vein: 3. Preinterventional Rutherford classifications: Class 1 : 3 legs (5 %), class 2 : 27 legs (51 %), class 3 : 16 legs (31 %), class 4 : 2 legs (4 %), class 5 : 5 legs (9 %). 40 % stents each were implanted ipsilateral, 60 % cross-over.

RESULTS

All interventions were successful regardless of a sometimes anatomically difficult access to the lesion. The device was characterised by a high flexibility and radial force and the stent did not shorten.

COMPLICATIONS

One distal stent dislocation during placement occurred, no puncture site complication. The mean diameter stenosis was reduced from 91 +/- 10 % (75 - 100 %) to 4 +/- 8 % (0 - 30 %). The ankle-brachial index was improved from 0.46 +/- 0.22 to 0.75 +/- 0.23 (p < 0.001). Post-interventional Rutherford classifications: Class 0 : 43 legs (81 %), class 1 : 5 legs (4,5 %), class 5 : 5 legs (4,5 %).

CONCLUSIONS

The new 6F-sheath compatible nitinol stent is characterised by a good flexibility, radial force, and a lack of shortening. By the reduction of the diameter of the device to 6F, the potential risk of a local bleeding complication may be reduced and 6F sealing devices will be usable. Disadvantages are the 0.018 inch guide-wire lumen and the limited stent sizes.

Emergence of ciprofloxacin resistance in nosocomial methicillin-resistant Staphylococcus aureus isolates. Resistance during ciprofloxacin plus rifampin therapy for methicillin-resistant S aureus colonization

We initiated a randomized, single-blinded trial of ciprofloxacin plus rifampin vs sulfamethoxazole and trimethoprim plus rifampin in the therapy for patients who underwent colonization with methicillin-resistant Staphylococcus aureus (MRSA). Patients who were colonized with MRSA received 2 weeks of either regimen. The study was terminated after the enrollment of 21 subjects due to the recognition of ciprofloxacin resistance in 10 of 21 new MRSA isolates during the last 2 months of the study. Five of the 10 patients with ciprofloxacin-resistant MRSA isolates had never received ciprofloxacin. Long-term (6-month) eradication had been achieved in only three of 11 ciprofloxacin plus rifampin and four of 10 sulfamethoxazole and trimethoprim plus rifampin recipients. The use of this new fluoroquinolone for the eradication of MRSA colonization is usually not effective and may risk the development of ciprofloxacin resistance in MRSA within the hospital environment.