[Effect of Hypericin on the Function of the Neuroretina: An Electroretinographic Study]

BACKGROUND

Hypericin is an important component of the Saint John's wort (Hypericum perforatum). It is assumed to inhibit intracellular signalling cascades, which contribute to neoangiogenesis. The phototoxic effect of hypericin on the retina was investigated in human retinal pigment epithelium (RPE); hypericin induces oxidative stress and has also been described to be an inhibitor of Ca(2+) influx channel in cultured RPE cells. The aim of our study is to evaluate the effect of hypericine on the function of the neuroretina.

METHODS

Isolated bovine retinas were perfused with an oxygen saturated nutrient solution (1 mL/min). We exposed the retina to a flashlight of 6.3 mlx every 5 min. The electroretinogram (ERG) was recorded as a transretinal potential using Ag/AgCl electrodes. ERGs were monitored before, during and after hypericin exposure.

RESULTS

In three independent experiments we investigated the effect of hypericin on the amplitude of the b-wave. In our experiments we observed a significant reduction of the amplitude of the b-wave to 87.1 ± 3.5 % (p = 0.02). This reduction was in all our experiments partially reversible. After hypericin wash-out the b-wave amplitude did not recover completely and did not return to the initial value (91.0 ± 5.1 %; not significant). We did not observe a significant effect of hypericin on the implicit time of the b-wave.

CONCLUSION

This study shows for the first time that hypericin influences retinal signal transduction, suggesting that hypericin impairs not only the RPE, but also affects retinal signalling and function.

Spinal cord grey matter abnormalities are associated with secondary progression and physical disability in multiple sclerosis

BACKGROUND

In multiple sclerosis (MS), pathological studies have identified substantial demyelination and neuronal loss in the spinal cord grey matter (GM). However, there has been limited in vivo investigation of cord GM abnormalities and their possible functional effects using MRI combined with clinical evaluation.

METHODS

We recruited healthy controls (HC) and people with a clinically isolated syndrome (CIS), relapsing remitting (RR) and secondary progressive (SP) MS. All subjects had 3 T spinal cord MRI with measurement of cord cross-sectional area and diffusion tensor imaging metrics in the GM and posterior and lateral column white matter tracts using region of interest analysis. Physical disability was assessed using the expanded disability status scale (EDSS) and motor components of the MS functional composite scale. We calculated differences between MS and HC using a ANOVA and associations with disability using linear regression.

RESULTS

113 people were included in this study: 30 controls, 21 CIS, 33 RR and 29 SPMS. Spinal cord radial diffusivity (RD), fractional anisotropy and mean diffusivity in the GM and posterior columns were significantly more abnormal in SPMS than in RRMS. Spinal cord GM RD (β=0.33, p<0.01) and cord area (β=-0.45, p<0.01) were independently associated with EDSS (R(2)=0.77); spinal cord GM RD was also independently associated with a 9-hole peg test (β=-0.33, p<0.01) and timed walk (β=-0.20, p=0.04).

CONCLUSIONS

The study findings suggest that pathological involvement of the spinal cord GM contributes significantly to physical disability in relapse-onset MS and SPMS in particular.

R-Type Voltage-Gated Ca²⁺ Channels in Cardiac and Neuronal Rhythmogenesis

During the past decades, an increasing number of ion channel and transporter types have been identified acting together to produce cardiac and neuronal pacemaker action potentials. The basis of pacemaker activity was understood in more detail by using single-microelectrode recordings on cells isolated from pacemaker regions. Meanwhile, this powerful technique was complemented by computer modeling and recombinant technologies, including gene inactivation of ion channels and transporters, which may be involved in the generation of the electrical activity of pacemaker cells. Several genes of the voltage-gated Ca(2+) channel (VGCC) family have been ablated, and their role in cardiac and neuronal pacemaking is compared in the present summary, focusing on the role of murine R-type voltage-gated Ca(2+) channels encoded by cacna1e and expressing the ion conducting subunit Cav2.3.

Serum inflammatory factors and circulating immunosuppressive cells are predictive markers for efficacy of radiofrequency ablation in non-small-cell lung cancer

In recent years, percutaneous radiofrequency ablation (RFA) has been developed as a new tool in the treatment of non-small-cell lung cancer (NSCLC) in non-surgical patients. There is growing evidence that RFA-mediated necrosis can modulate host immune responses. Here we analysed serum inflammatory factors as well as immunosuppressive cells in the peripheral blood to discover possible prognostic indicators. Peripheral blood and serum samples were collected before RFA and within 3 months after the treatment in a total of 12 patients. Inflammatory cytokines and growth factors were measured in serum by the Bio-Plex assay. Myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs ) were evaluated in the peripheral blood via flow cytometry. In patients developing local or lymphogenic tumour relapse (n=4), we found an early significant increase in the concentration of tumour necrosis factor (TNF)-α as well as chemokine (C-C motif) ligand (CCL)-2 and CCL-4 compared to patients without relapse (n=4) and healthy donors (n=5). These changes were associated with an elevated activity of circulating MDSC indicated by an increased nitric oxide (NO) production in these cells. Elevated serum levels of TNF-α, CCL-2 and CCL-4 associated with an increased NO production in circulating MDSCs might be an early indicator of the incomplete RFA and subsequently a potential tumour relapse in NSCLC.

Differences in neuroradiology training programs around the world

BACKGROUND AND PURPOSE

No previous study compares neuroradiology training programs and teaching schedules across the globe, to our knowledge. This study was conducted to better understand international program requisites.

MATERIALS AND METHODS

Data from 43 countries were collected by an e-mail-based questionnaire (response rate, 84.0%). Radiologists across the world were surveyed regarding the neuroradiology training schemes in their institutions. Answers were verified by officers of the national neuroradiology societies.

RESULTS

While many countries do not provide fellowship training in neuroradiology (n = 16), others have formal postresidency curricula (n = 27). Many programs have few fellows and didactic sessions, but the 1- or 2-year duration of fellowship training is relatively consistent (n = 23/27, 85%).

CONCLUSIONS

There is a wide variety of fellowship offerings, lessons provided, and ratios of teachers to learners in neuroradiology training programs globally.

[ARDS after Incidental Aspiration of Petroleum in an Adult]

Petroleum aspiration as a reason for lipid pneumonia is a rare complication. Mostly children are affected and mortality rates are low. In most case series, virtually every subject survived.We describe here the case of a patient who developed ARDS and pneumatoceles with a fatal outcome. Due to the undulant nature of the disease, multipe thoracic CT were performed, enabling us to describe the precise radiologic course of the disease.

Joint research towards a better radiation protection-highlights of the Fifth MELODI Workshop

MELODI is the European platform dedicated to low-dose radiation risk research. From 7 October through 10 October 2013 the Fifth MELODI Workshop took place in Brussels, Belgium. The workshop offered the opportunity to 221 unique participants originating from 22 countries worldwide to update their knowledge and discuss radiation research issues through 118 oral and 44 poster presentations. In addition, the MELODI 2013 workshop was reaching out to the broader radiation protection community, rather than only the low-dose community, with contributions from the fields of radioecology, emergency and recovery preparedness, and dosimetry. In this review, we summarise the major scientific conclusions of the workshop, which are important to keep the MELODI strategic research agenda up-to-date and which will serve to establish a joint radiation protection research roadmap for the future.

[Thermal ablation of malignant lung tumours]

In Germany in about 50,000 patients lung cancer is diagnosed per year - actually it is the tumour most likely to result in death. Furthermore, the lung is the second most common site of distant metastases of extrathoracic tumours. In recent years image-guided thermo-ablative techniques are increasingly being used in patients unable to undergo surgery. Radiofrequency ablation (RFA) is the most frequently used technique, cryoablation, microwave-ablation and laser-induced thermoablation are new and promising techniques. Actually there is only a small evidence base, only retrospective and prospective case series have been published as yet. Randomised controlled trials have not been conducted up to now. RFA results in a local control of tumour growth in about 90 %. Long-term results indicate 5-year survival rates of 20-61 % in patients with lung cancer or lung metastases. Pneumothorax is the most common morbidity - requiring drainage in about 10 % after the intervention. In the long term no loss of pulmonary function results after the ablation of peripheral lesions. Peripherally localised tumours < 3 cm in diameter are the most promising targets, the treatment of centrally localised tumours is subtle due to the "heat-loss" effect. The current evidence is insufficient to develop a procedure for differential indication of ablative techniques versus stereotactic radiotherapy. Tumour ablation always should be indicated on the basis of interdisciplinary consensus (including pulmonologists, oncologists, thoracic surgeons, radiotherapists). Inoperability should be assigned by the thoracic surgeon himself. Actually it cannot be considered an alternative to surgery for the treatment of malignant lung tumours with curative intent, however thermal ablation broadens the range of treatment options for patients being no candidates for surgery.

Ultra-narrow linewidth, stable and tunable laser source for optical communication systems and spectroscopy

A novel ultra-narrow linewidth, stable and tunable single-line laser source is demonstrated and experimentally performed. The single spectral line laser is achieved by selecting and amplifying one spectral comb line of a femtosecond-fiber laser via polarization pulling assisted stimulated Brillouin scattering. Stabilization and tuning is performed by additional modulation. First proof of concept results show possible linewidths below 1 Hz and an SNR of 47 dB with a tunability of more than 100 nm and a relative stability of ±160  mHz over 5 h. Such a laser source gives high potential for many different applications like spectroscopy and optical communications.

[Fever of unknown origin in 74-year-old multimorbid man]

A 74-year-old multimorbid man was admitted with fever of unknown origin. Over time the fever ceased spontaneously. The patient developed signs of a right heart failure without evidence of a primarily cardiac pathogenesis and died of acute right heart failure. Miliary tuberculosis that had lead to pulmonary artery hypertension was diagnosed at autopsy.

[Capsule endoscopy in a supra-regional network corporation: experience in more than 1000 cases]

INTRODUCTION

Capsule endoscopy (CE) is firmly established as a standard procedure in the diagnostic algorithm of mid gastrointestinal (GI) bleeding. Despite its excellent diagnostic yield, missing expertise, reading time and financial expenditure limit an area-wide availability. A multicentric cooperation might compensate these disadvantages.

METHODS

The CE device was bought by a centrally located hospital (CH). CE-equipment is transported to the network partner (NP) on request and the procedure performed at the spot. Video reading is exclusively done in the CH.

RESULTS

Between January 2002 and July 2013, 1026 CE (548 m, 478f; 64 ± 16, 13 - 93 yrs.) were performed within the network. 744/1026 (73 %) CE were done at 17 NP, 282/1026 (27 %) in the CH. Between 2002 (n = 39) and 2012 (n = 136) the annual number of CE increased threefold. Leading indication for CE was suspected mid GI-bleeding (80 %). Mean latencies between requested date and actual examination were less than 24 h and 2 days between CE performance and report. 95 % of the capital investment in each cooperating hospital could be avoided by sharing one workstation within the network.

CONCLUSION

The experience from more than 1000 CE show that long-term multicentric utilization of CE equipment is feasible. Such a network runs at stable procedural quality levels similar to an in-house supply, allows an economic as well as area-wide availability of CE and improves reading expertise by centralized video evaluation.