Serum Resistance of Mycoplasma agalactiae Strains and Mutants Bearing Different Lipoprotein Profiles

In order to spread systemically, resistance against complement and other factors present in serum is an important trait in pathogenic bacteria. The variable proteins of Mycoplasma agalactiae (Vpmas) have been shown to affect differential adhesion, invasion and immune evasion, and undergo high-frequency phase-variation in expression. However, nothing is known about their involvement in M. agalactiae’s serum susceptibility. To evaluate this, the PG2 strain, the GM139 strain and the six Vpma phase-locked mutants (PLMs, PLMU to PLMZ) were tested for their ability to survive in the presence of non-sensitized and sensitized sheep serum, as well as guinea pig complement. Additionally, the reactivity of the sensitized sheep serum was analysed on the strains via western blotting. Overall data demonstrate PG2 strain to be more susceptible to sheep serum compared to the GM139 strain bearing a different Vpma profile. Significant differences were also observed between the different PLMs, with PLMU and PLMX showing the highest serum susceptibility in serum, while the other PLMs expressing longer Vpma proteins were more resistant. The results are in good correlation with previous studies where shorter lipoprotein variants contributed to a higher susceptibility to complement. Since none of the tested strains and PLMs were susceptible to non-sensitized sheep serum, antibodies seem to play an important role in serum killing.

Das Schülerlabor als Ort authentischer Wissenschaftsvermittlung? Entwicklung und Validierung eines Fragebogens zur Erfassung der Authentizitätswahrnehmung der Wissenschaftsvermittlung im Schülerlabor

Im vorliegenden Beitrag wird ein Fragebogen zur mehrdimensionalen Erfassung der Wahrnehmung von Authentizität in der Wissenschaftsvermittlung (FEWAW) vorgestellt. Die Entwicklung des Messinstruments mit den Authentizitätsdimensionen Vermittler, Ort, Vorgehen und Innovation erfolgte auf der Grundlage theoretischer Modelle zur Wahrnehmung von Authentizität der Wissenschaftsvermittlung. In einer Validierungsstudie mit N = 337 Schülerinnen und Schülern im Alfried Krupp-Schülerlabor der Ruhr-Universität Bochum konnte die faktorielle Struktur mittels konfirmatorischer Faktorenanalysen bestätigt werden. Die internen Konsistenzen der vier Dimensionen sind zufriedenstellend (Cronbachs α ≥ 0,81). Außerdem konnte die Messinvarianz des Instruments für das Geschlecht sowie die Klassenstufe bestätigt werden. Die Zusammenhänge der Authentizitätsdimensionen mit Außenkriterien, wie z. B. epistemologischen Überzeugungen, liefern weitere Hinweise auf die Validität des Messinstruments. Insgesamt stellt der FEWAW ein geeignetes Instrument für die mehrdimensionale Erfassung der Authentizitätswahrnehmung in der Wissenschaftsvermittlung dar.

Rise of extremity fractures and sport accidents in children at 8-12 years and increase of admittance via the resuscitation room over a decade

Introduction

In an emergency department, the majority of pediatric trauma patients present because of minor injuries. The aim of this study was to evaluate temporal changes in age-related injury pattern, trauma mechanism, and surgeries in pediatric patients.

Methods

This retrospective study included patients < 18 years of age following trauma from 01/2009 to 12/2018 at a level I trauma center. They were divided into two groups: group A (A: 01/2009 to 12/2013) and group B (B: 01/2014 to 12/2018). Injury mechanism, injury pattern, and surgeries were analyzed. As major injuries fractures, dislocations, and organ injuries and as minor injuries contusions and superficial wounds were defined.

Results

23,582 patients were included (58% male, median age 8.2 years).

There was a slight increase in patients comparing A (n = 11,557) and B (n = 12,025) with no difference concerning demographic characteristics.

Significant more patients (A: 1.9%; B: 2.4%) were admitted to resuscitation room, though the number of multiple injured patients was not significantly different.

In A (25.5%), major injuries occurred significantly less frequently than in B (27.0%), minor injuries occurred equally. Extremity fractures were significantly more frequent in B (21.5%) than in A (20.2%), peaking at 8–12 years.

Most trauma mechanisms of both groups were constant, with a rising of sport injuries at 8–12 years.

Conclusion

Although number of patients increases only slightly over a decade, there was a clear increase in major injuries, particularly extremity fractures, peaking at 8–12 years. At this age also sport accidents significantly increased.

At least, admittance to resuscitation room rose but without an increase of multiple injured patients.

Correction of Motion Artifacts Using a Multiscale Fully Convolutional Neural Network

BACKGROUND AND PURPOSE

Motion artifacts are a frequent source of image degradation in the clinical application of MR imaging (MRI). Here we implement and validate an MRI motion-artifact correction method using a multiscale fully convolutional neural network.

MATERIALS AND METHODS

The network was trained to identify motion artifacts in axial T2-weighted spin-echo images of the brain. Using an extensive data augmentation scheme and a motion artifact simulation pipeline, we created a synthetic training dataset of 93,600 images based on only 16 artifact-free clinical MRI cases. A blinded reader study using a unique test dataset of 28 additional clinical MRI cases with real patient motion was conducted to evaluate the performance of the network.

RESULTS

Application of the network resulted in notably improved image quality without the loss of morphologic information. For synthetic test data, the average reduction in mean squared error was 41.84%. The blinded reader study on the real-world test data resulted in significant reduction in mean artifact scores across all cases (P < .03).

CONCLUSIONS

Retrospective correction of motion artifacts using a multiscale fully convolutional network is promising and may mitigate the substantial motion-related problems in the clinical MRI workflow.

A simulation platform using 3D printed neurovascular phantoms for clinical utility evaluation of new imaging technologies

Modern 3D printing technology allows rapid prototyping of vascular phantoms based on an actual human patient with a high degree of precision. Using this technology, we present a platform to accurately simulate clinical views of neuro-endovascular interventions and devices. The neuro-endovascular interventional phantom has a 3D printed cerebrovasculature model derived from a patient CT angiogram and embedded inside a human skull providing bone attenuation. Acrylic layers were placed underneath and on top of the skull, simulating entrance and exit tissue attenuation and also simulating forward scatter. The 3D model was connected to a pulsatile flow loop for simulating interventions using clinical devices such as catheters and stents. To validate the x-ray attenuation and establish clinical accuracy, the automatic exposure selection by a clinical c-arm system for the phantom was compared with that for a commercial anthropomorphic head phantom (SK-150, Phantom Labs). The percentage difference between automatic exposure selection for the neuro-intervention phantom and the SK-150 phantom was under 10%. By changing 3D printed models, various patient diseased anatomies can be simulated accurately with the necessary x-ray attenuation. Using this platform various interventional procedures were performed using new imaging technologies such as a high-resolution x-ray fluoroscope and a dose-reduced region-of-interest attenuator and differential temporally filtered display for enhanced interventional imaging. Simulated clinical views from such phantom-based procedures were used to evaluate the potential clinical performance of such new technologies.

High energy probe for detecting lymph node metastases with 18F-FDG in patients with head and neck cancer

Aim of this study was to validate a newly developed high energy probe (positron emission probe, PEP) optimised for localising PET tracers in vivo. Patients and methods: Physical investigations included determination of full width at half maximum (FWHM) values at a distance of 1 cm and angular resolution using different point sources. Values obtained with the new probe were compared to those of a conventional gamma probe (CGP). Additionally, PET studies were performed in 36 patients (6 women, 30 men) with proven head and neck cancer and suspected lymph node metastases (Axis, Marconi/Philips) after administering 250–320 MBq 18F-FDG. Subsequent to PET investigations 18F-FDG uptake in cervical regions was measured using the PEP. PEP investigations were carried out bilaterally in 5 lymph node (LN) levels (Robbins’ classification of the neck). Results of probe studies were correlated with visual and semiquantitative PET evaluations, US and histological findings. Results: FWHM of the new probe was 7 mm (CGP 22 mm) at 662 keV (137Cs) and angular resolution resulted in 8° (CGP 60°). In 29 out of 36 patients LN metastases were suspected due to ultrasound investigations. After neck dissection, histology confirmed LN metastases in 21 patients. Sensitivity (sens.) of US amounted to 95% and specificity to 40%. In 18/21 patients LN metastases were detected by PET (sens. 86%). PET scans failed to diagnose the LN status correctly in 6/36 patients (accuracy 83%). Employing the PEP probe in 20/21 patients LN metastases were identified (sens. 95%), and LN status was determined accurately in 29/36 patients (accuracy 81%). Tumour/ background ratios of PEP measurement and results of semiquantitative PET analyses were comparable. Conclusions: PEP measurement is a promising method for preoperative planning of the extent of neck dissection in patients with head and neck cancer and further for radioguided localising PET tracer accumulation during surgery.

Towards predicting the encoding capability of MR fingerprinting sequences

Sequence optimization and appropriate sequence selection is still an unmet need in magnetic resonance fingerprinting (MRF). The main challenge in MRF sequence design is the lack of an appropriate measure of the sequence's encoding capability. To find such a measure, three different candidates for judging the encoding capability have been investigated: local and global dot-product-based measures judging dictionary entry similarity as well as a Monte Carlo method that evaluates the noise propagation properties of an MRF sequence. Consistency of these measures for different sequence lengths as well as the capability to predict actual sequence performance in both phantom and in vivo measurements was analyzed. While the dot-product-based measures yielded inconsistent results for different sequence lengths, the Monte Carlo method was in a good agreement with phantom experiments. In particular, the Monte Carlo method could accurately predict the performance of different flip angle patterns in actual measurements. The proposed Monte Carlo method provides an appropriate measure of MRF sequence encoding capability and may be used for sequence optimization.

Clinical outcome after alternative treatment of scaphoid fractures and nonunions

PURPOSE

Achieving stable fixation of scaphoid fractures and nonunions continues to be a challenge. Compression screw fixation has been the current standard surgical procedure. However, in some cases, bone healing cannot be achieved and requires further revision. Recent series reintroduced volar plating as valid option for stable fixation. The aim of the study was to review clinical outcome of alternative scaphoid treatment.

METHODS

From 2011 to 2014, nine patients with scaphoid fracture were treated by Headless Compression Screw (HCS) and seven patients with scaphoid nonunion by HCS or volar mini condylar plate with bone graft. The average age was 34.4 years and the average time to follow-up was 19.3 months. From 1996 to 1998, 38 patients with scaphoid nonunion were treated using compression screw (S-group) or volar mini condylar plate (P-group) with bone graft. The average age was 39.6 years and the average time to follow-up was 26.2 months.

RESULTS

The union rate was 100%. For scaphoid fractures, the mean Modified Mayo Wrist Score (MMWS) was 94.1 and the DASH score 7.4. From 2011 to 2014, the MMWS was 87.9 and the DASH score 7 in scaphoid nonunions. In the period between 1996 and 1998, the MMWS was 67.2 in the P-group and 58.6 in the S-group, and the DASH score 16.8 and 28.2.

CONCLUSIONS

Our study demonstrated that appropriate application of the HCS was able to produce very satisfactory results in scaphoid fractures and nonunions. In our opinion, however, the method of scaphoid plate osteosynthesis can achieve a higher degree of stability, particularly rotational stability, in case of multifragmentary avascular scaphoid nonunions.

Acute adrenal insufficiency: an aide-memoire of the critical importance of its recognition and prevention

Adrenal crisis is a life-threatening emergency that causes significant excess mortality in patients with adrenal insufficiency. Delayed recognition by medical staff of an impending adrenal crisis and failure to give timely hydrocortisone therapy within the emergency department continue to be commonly encountered, even in metropolitan teaching hospitals. Within the authors' institutions, several cases of poorly handled adrenal crises have occurred over the last 2 years. Anecdotal accounts from members of the Addison's support group suggest that these issues are common in Australia. This manuscript is a timely reminder for clinical staff on the critical importance of the recognition, treatment and prevention of adrenal crisis. The manuscript: (i) outlines a case and the clinical outcome of sub-optimally managed adrenal crisis, (ii) summarises the clinical features and acute management of adrenal crisis, (iii) provides recommendations on the prevention of adrenal crisis and (iv) provides guidance on the management of 'sick days' in patients with adrenal insufficiency.

Outcomes of Endodontic Therapy Comparing Conventional Sodium Hypochlorite Irrigation with Passive Ultrasonic Irrigation Using Sodium Hypochlorite and Ethylenediaminetetraacetate. A Retrospective Analysis

The aim of the present study was to investigate the clinical outcomes of two different standardized endodontic irrigation protocols. It was assumed that the additional use of ethylenediaminetetraacetate (EDTA) and passive ultrasonic irrigation (PUI) would result in an increased rate of absence of symptoms and remission based on the periapical index (PAI) compared to passive irrigation using only sodium hypochlorite (NaOCl).

Data and radiographs from 199 teeth retrieved from the institutional endodontic database were analyzed retrospectively. In 106 teeth irrigation was performed using only NaOCl (protocol 1). Ninety-three teeth were irrigated using NaOCl and EDTA (protocol 2). Chlorhexidine (CHX) was additionally used in revision treatments in both groups. All irrigants in group 2 were activated by PUI.

Mean follow-up periods were: protocol 1 = 9.2 ± 4.4 and protocol 2 = 6.6 ± 2.5 months (p < 0.0001 (chi-square test). The frequencies of the PAI_masterpoint and PAI_follow-up scores did not differ significantly between teeth, which received either protocol 1 or 2 (p = 0.555 and 0.138). Statistical analysis revealed no significant association between treatment success (absence of clinical symptoms and PAI_follow-up = I or PAI_masterpoint > PAI_follow-up > I) and the applied protocol (success rates: protocol 1 = 72.6% vs. protocol 2 = 82.8%; p = 0.203). Furthermore, the frequency of extractions did not differ significantly between the two protocols (p = 0.102). No association was found between follow-up time and treatment success (p = 0.888).

The hypothesis was not confirmed. Even though the obtained success rate was higher after supplementing the irrigation protocol with EDTA and PUI, no significance was recorded. Hence, protocol 2 was not superior to protocol 1 regarding therapy success, at least within the limited follow-up period. It may be cautiously concluded that sufficient mechanical debridement combined with passive NaOCl irrigation results in comparably high success rates compared to EDTA and PUI.

Local hyperthermia, hyperfractionated radiation, and cisplatin in preirradiated recurrent lymph node metastases of recurrent head and neck cancer

Large tumor size is a negative prognostic variable for attaining complete regression (CR) with local hyperthermia (HT) and radiotherapy (RT). Such poor prognosis lesions (i.e., >7 cm(2) or >14 cm(3)) have an expected CR rate of similar to 30+/-8%. To improve on this result we added cisplatin to HT and RT with standard fractionation (std Fx) in an earlier study, and observed a 19% CR rate in head and neck (H&N) patients. We now report the results of a second generation trial combining HT, cisplatin (40 mg/m(2)) and hyperfractionated RT in a series of 13 pretreated poor prognosis H&N patients. Therapy encompassed 44 triple modality sessions and was well tolerated: toxicity included one episode of grade-3 skin reaction and one grade 1 leukopenia. Although the overall remission rate was 92%, the CR rate was only 8%; this resulted in early closure of this trial concluding that hyperfractionated RT had no (over std Fx RT) benefit in this combined modality approach.

[Skeletal tuberculosis of the distal radius during pregnancy]

We present a case of a pregnant woman (32nd gestational week) that suffered from a chronic non-healing wound at the distal radius. Skeletal tuberculosis was finally diagnosed and treated successfully with staged surgical therapy combined with appropriate medication. One year after surgical treatment, the outcome of the mother was excellent and the baby did not suffer from any disease related to operative procedures or pharmacotherapy. Operative treatment of skeletal tuberculosis (especially osteoarticular and vertebral tuberculosis) in combination with tuberculostatic therapy during pregnancy and lactation seem to be the appropriate treatment with minimal risk for the child and excellent outcome for the mother.

[A dural fistula as a rare cause for a pulse-synchronized tinnitus aurium]

Pulse-synchronized tinnitus aurium is commonly caused by vascular processes within the area of the temporal bone. With a microphone or a stethoscope in the external ear or on the mastoid perceptible noises can be heard by the physician. The most important differential diagnoses of an objective tinnitus are paraganglioma of the glomus jugulare or the glomus tympanicum, vascular stenosis, arteriovenouse malformations, aneurysms and atypic findings of the bulbus venae jugularis interna of the temporal bone. In case of a pulse-synchronized tinnitus purposeful use of neuroradiological diagnostic can lead to a correct diagnosis. The indication for invasive intervention of dural fistulas depends on the number and the hemodynamic relevance of these fistulas and on individual suffering of the patient. Even if it does not succeed, all to embolize AV-short-circuits, it is possible to reduce the intensity of the tinnitus in order to continue with conservative therapy.