Increasing protein identifications in bottom-up proteomics of T. castaneum - Exploiting synergies of protein biochemistry and bioinformatics

Depending on the respective research question, LC-MS/MS based bottom-up proteomics poses challenges from the initial biological sample all the way to data evaluation. The focus of this study was to investigate the influence of sample preparation techniques and data analysis parameters on protein identification in Tribolium castaneum by applying free software proteomics platform Max Quant. Multidimensional protein extraction strategies in combination with electrophoretic or chromatographic off-line protein pre-fractionation were applied to enhance the spectrum of isolated proteins from T. castaneum and reduce the effect of co-elution and ion suppression effects during nano-LC-MS/MS measurements of peptides. For comprehensive data analysis, MaxQuant was used for protein identification and R for data evaluation. A wide range of parameters were evaluated to gain reproducible, reliable, and significant protein identifications. A simple phosphate buffer, pH 8, containing protease and phosphatase inhibitor cocktail and application of gentle extraction conditions were used as a first extraction step for T.castaneum proteins. Furthermore, a two-dimensional extraction procedure in combination with electrophoretic pre-fractionation of extracted proteins and subsequent in-gel digest resulted in almost 100% increase of identified proteins when compared to chromatographic fractionation as well as one-pot-analysis. The additionally identified proteins could be assigned to new molecular functions or cell compartments, emphasizing the positive effect of extended sample preparation in bottom-up proteomics. Besides the number of peptides during post-processing, MaxQuant's Match between Runs exhibited a crucial effect on the number of identified proteins. A maximum relative standard deviation of 2% must be considered for the data analysis. Our work with Tribolium castaneum larvae demonstrates that sometimes - depending on matrix and research question - more complex and time-consuming sample preparation can be advantageous for isolation and identification of additional proteins in bottom-up proteomics.

Active and passive microrheology with large tracers in hard colloids

The dynamics of a tracer particle in a bath of quasi-hard colloidal spheres is studied by Langevin dynamics simulations and mode coupling theory (MCT); the tracer radius is varied from equal to up to seven times larger than the bath particles radius. In the simulations, two cases are considered: freely diffusing tracer (passive microrheology) and tracer pulled with a constant force (active microrheology). Both cases are connected by linear response theory for all tracer sizes. It links both the stationary and transient regimes of the pulled tracer (for low forces) with the equilibrium correlation functions; the velocity of the pulled tracer and its displacement are obtained from the velocity auto-correlation function and the mean squared displacement, respectively. The MCT calculations give insight into the physical mechanisms: At short times, the tracer rattles in its cage of neighbours, with the frequency increasing linearly with the tracer radius asymptotically. The long-time tracer diffusion coefficient from passive microrheology, which agrees with the inverse friction coefficient from the active case, arises from the transport of transverse momentum around the tracer. It can be described with the Brinkman equation for the transverse flow field obtained in extension of MCT, but cannot be recovered from the MCT kernel coupling to densities only. The dynamics of the bath particles is also studied; for the unforced tracer the dynamics is unaffected. When the tracer is pulled, the velocity field in the bath follows the prediction of the Brinkman model, but different from the case of a Newtonian fluid.

Metabolic and molecular effects of dietary extra virgin olive oil in blood and placenta of women with GDM

Gestational diabetes mellitus (GDM) increases the risks of maternal, placental, and neonatal complications. Previously, we found that a diet enriched in extra virgin olive oil (EVOO) prevents increased maternal triglyceridemia and placental proinflammatory markers in a cohort of GDM patients. The aim of this work was to evaluate maternal circulating markers of insulin resistance, placental collagen, glycogen and lipid levels, and placental levels of proteins, mRNAs, and a microRNA involved in the endocytic pathway in the same cohort of control women and women with GDM who received or did not receive a diet enriched in EVOO (36 g/day) from weeks 24 to 28 of pregnancy until term.

Results

At term, the TG/HDL cholesterol ratio, fatty acid binding protein 4 circulating levels, and maternal BMI were increased in the GDM patients, alterations prevented by the maternal diet enriched in EVOO. Although there were no changes in placental lipid levels and lipid profile, GDM placentas were thicker than controls and showed increased glycogen and collagen content, alterations prevented by the EVOO enriched diet. GDM placentas showed increases in megalin levels, in the expression of several genes involved in the endocytic pathway, and in miR-199, which targets these genes, alterations prevented by the maternal diet enriched in EVOO.

Conclusions

We identified novel beneficial effects of an EVOO-enriched diet in GDM women, a diet capable of regulating maternal insulin resistance, the structure and metabolism of the placenta, and the placental endocytic pathway, suggesting effects that may be beneficial for fetal development.

[Effect of low-dose PDT on perfusion of the choriocapillaris in cCSCR : An OCT-angiography-based study]

BACKGROUND

In patients with chronic central serous chorioretinopathy (cCSCR) it is assumed that low-dose photodynamic therapy (PDT) induces short-term hypoperfusion of the choriocapillaris, which leads to long-term choroidal vascular remodeling and subsequent reduction of vascular hyperpermeability and leakage; however, it remains unclear whether the hypoperfusion completely returns to normal. The main aim of the retrospective study was to analyze the choroidal flow signal after treatment with low-dose PDT by optical coherence tomography-angiography (OCT‑A).

PATIENTS AND METHODS

In this study 16 eyes with a total of 19 treated areas were included. Aside from visual acuity and metamorphopsia checks, all patients underwent enhanced depth imaging-OCT (EDI-OCT) and OCT‑A in the areas treated with low-dose PDT. In the present study, the flow signal in the choriocapillaris and choroidal thickness were measured retrospectively both in the PDT-treated area and in a non-treated reference area located in close proximity with similar eccentricity to the center of the fovea.

RESULTS

The study found a mean reduction of 33% (p < 0.001) of the choroidal flow signal in the treated area compared to the reference area and an average decrease in choroidal thickness of 71 µm (p = 0.001). In the long term 7 out of 10 patients suffered from metamorphopsia despite the low-dose PDT; however, visual acuity was improved in almost half of the patients by the treatment.

CONCLUSION

Using OCT‑A it could be shown that at the choriocapillaris level, hypoperfusion persists in spite of low-dose PDT. Thus, the choroidal vascular remodeling is not able to completely compensate for the hypoperfusion induced by thrombosis.

Lorentz resonance in the homogenization of plasmonic crystals

We explain the Lorentz resonances in plasmonic crystals that consist of two-dimensional nano-dielectric inclusions as the interaction between resonant material properties and geometric resonances of electrostatic nature. One example of such plasmonic crystals are graphene nanosheets that are periodically arranged within a non-magnetic bulk dielectric. We identify local geometric resonances on the length scale of the small-scale period. From a materials perspective, the graphene surface exhibits a dispersive surface conductance captured by the Drude model. Together these phenomena conspire to generate Lorentz resonances at frequencies controlled by the surface geometry and the surface conductance. The Lorentz resonances found in the frequency response of the effective dielectric tensor of the bulk metamaterial are shown to be given by an explicit formula, in which material properties and geometric resonances are decoupled. This formula is rigorous and obtained directly from corrector fields describing local electrostatic fields inside the heterogeneous structure. Our analytical findings can serve as an efficient computational tool to describe the general frequency dependence of periodic optical devices. As a concrete example, we investigate two prototypical geometries composed of nanotubes and nanoribbons.

[MEK inhibitor-associated retinopathy under binimetinib treatment for cutaneous malignant melanoma]

Die Behandlungsmöglichkeiten für Patienten mit metastasierendem Melanom (MM) wurden in den letzten Jahren mit der Zulassung von neuen Medikamenten dramatisch erweitert. Die MEK(mitogen-aktivierte Proteinkinase-Kinasen)- und BRAF(Serin/Threonin-Kinase B-Raf kodierendes Gen)-Hemmer-Kombinationstherapie gehört aktuell zum Versorgungsstandard für das Stadium IIIC/IV des BRAF-mutierten Melanoms. MEKAR (MEK-Inhibitor-assoziierte Retinopathie) werden bei Patienten mit metastasierendem Melanom beobachtet, die mit einer solchen Kombinationstherapie behandelt werden bzw. wurden. Wir berichten über den Fall eines 72-jährigen Patienten, der eine solche Pathologie unter der Therapie mit Binimetinib in Kombination mit Nivolumab erlitt. Diese Kasuistik verdeutlicht die Wichtigkeit einer interdisziplinären Zusammenarbeit bei der Behandlung von MM-Patienten.

A European multicentre evaluation of detection and typing methods for human enteroviruses and parechoviruses using RNA transcripts

Polymerase chain reaction (PCR) detection has become the gold standard for diagnosis and typing of enterovirus (EV) and human parechovirus (HPeV) infections. Its effectiveness depends critically on using the appropriate sample types and high assay sensitivity as viral loads in cerebrospinal fluid samples from meningitis and sepsis clinical presentation can be extremely low. This study evaluated the sensitivity and specificity of currently used commercial and in-house diagnostic and typing assays. Accurately quantified RNA transcript controls were distributed to 27 diagnostic and 12 reference laboratories in 17 European countries for blinded testing. Transcripts represented the four human EV species (EV-A71, echovirus 30, coxsackie A virus 21, and EV-D68), HPeV3, and specificity controls. Reported results from 48 in-house and 15 commercial assays showed 98% detection frequencies of high copy (1000 RNA copies/5 µL) transcripts. In-house assays showed significantly greater detection frequencies of the low copy (10 copies/5 µL) EV and HPeV transcripts (81% and 86%, respectively) compared with commercial assays (56%, 50%; P = 7 × 10-5 ). EV-specific PCRs showed low cross-reactivity with human rhinovirus C (3 of 42 tests) and infrequent positivity in the negative control (2 of 63 tests). Most or all high copy EV and HPeV controls were successfully typed (88%, 100%) by reference laboratories, but showed reduced effectiveness for low copy controls (41%, 67%). Stabilized RNA transcripts provide an effective, logistically simple and inexpensive reagent for evaluation of diagnostic assay performance. The study provides reassurance of the performance of the many in-house assay formats used across Europe. However, it identified often substantially reduced sensitivities of commercial assays often used as point-of-care tests.

Homogenization of plasmonic crystals: seeking the epsilon-near-zero effect

By using an asymptotic analysis and numerical simulations, we derive and investigate a system of homogenized Maxwell's equations for conducting material sheets that are periodically arranged and embedded in a heterogeneous and anisotropic dielectric host. This structure is motivated by the need to design plasmonic crystals that enable the propagation of electromagnetic waves with no phase delay (epsilon-near-zero effect). Our microscopic model incorporates the surface conductivity of the two-dimensional (2D) material of each sheet and a corresponding line charge density through a line conductivity along possible edges of the sheets. Our analysis generalizes averaging principles inherent in previous Bloch-wave approaches. We investigate physical implications of our findings. In particular, we emphasize the role of the vector-valued corrector field, which expresses microscopic modes of surface waves on the 2D material. We demonstrate how our homogenization procedure may set the foundation for computational investigations of: effective optical responses of reasonably general geometries, and complicated design problems in the plasmonics of 2D materials.

Influenza B virus infections in Western Saxony, Germany in three consecutive seasons between 2015 and 2018: Analysis of molecular and clinical features

BACKGROUND

The impact of annual influenza epidemics and prevailing strains varies worldwide and regional. The majority of vaccines used contained two influenza A strains and only one influenza B strain (trivalent vaccine).

AIM

The aim of the study was to compare laboratory confirmed influenza B cases during three consecutive years with respect to vaccination history, clinical symptoms and molecular virology.

METHODS

Partial HA gene sequences were analyzed for lineage determination and complete HA sequence in cases with reported vaccination and in fatal cases. Clinical data were retrieved from patient charts.

FINDINGS

During the 2015/16 season, 75 influenza B cases were retrieved; 11 in 2016/17, and 274 in 2017/18. The frequency of Yamagata-lineage strains increased from 7.6% to 100%. No difference was detected in the relative frequency of co-morbidities in season 2017/18. 37.7% of the adult patients and 4.5% of pediatric patients were vaccinated against influenza.

INTERPRETATION

Phylogenetically, Yamagata strains clustered similarly in 2017/2018 when compared to the previous two influenza seasons. While the relative frequency of influenza B cases differed, the clinical symptoms remained similar.

CONCLUSION

World Health Organization recommendations for the use of tetravalent vaccines that contain two influenza B strains (Yamagata and Victoria) in addition to the two influenza A strains (H1N1 and H3N2) should be implemented in national vaccination guidelines.

FUNDING

This research was partially supported by the Association of Sponsors and Friends of Leipzig University.

[Vitrectomy and iOCT-assisted inverted ILM flap technique in patients with full thickness macular holes]

BACKGROUND

In large full thickness macular holes (FTMH) the closure rate after vitrectomy and conventional internal limiting membrane (ILM) peeling is less than 90%. The aim of this study was to examine the visual acuity and anatomical success rate with high-resolution optical coherence tomography (OCT) after transconjunctival sutureless 23-gauge pars plana vitrectomy as well as intraoperative OCT (iOCT) and Brilliant Peel (BP)-assisted ILM peeling using the inverted ILM flap technique in patients with large FTMHs.

METHOD

In this retrospective study 25 eyes of 25 consecutive patients with large FTMH were treated by 23-G vitrectomy with BP and iOCT-assisted ILM peeling using the inverted ILM flap technique followed by gas tamponade. In all patients best corrected visual acuity (BCVA) and the maximum diameter, base and height of the FTMH as well as intraretinal alterations were measured preoperatively using high-resolution spectral domain OCT (SD-OCT, Spectralis, Heidelberg Engineering, Germany). The BCVA was measured after 1, 3, and 6 months. Additionally, the closure rate and the microstructural integrity of the outer retinal layers, e.g. external limiting membrane (ELM), ellipsoid zone und photoreceptor outer segment (OS) were registered in the SD-OCT and correlated with the results of BCVA after macular hole surgery.

RESULTS

In all surgical procedures with the inverted ILM flap technique the application of iOCT enabled a good visualization and a controlled positioning of the ILM flaps. At baseline mean BCVA was 0.2 (0.7 logMAR) and improved significantly after 1, 3 und 6 months to 0.4 (0.4 logMAR), 0.5 (0.3 logMAR) and 0.63 (0.2 logMAR), respectively. The closure rate of the FTMHs was 100%. Microstructural integrity of the outer retinal layers was evaluated semiquantitatively and showed good correlation with BCVA.

CONCLUSION

Vitrectomy with BP and iOCT-assisted ILM peeling using the inverted ILM flap technique in patients with large FTMH is a very controlled and safe microsurgical strategy and shows good functional and anatomical results. The morphology of the FTMH, the ILM flap and the position of the inverted ILM flap under air was well visualized by IOCT. The microstructural integrity of the outer retinal layers is displayed in detail on SD-OCT and represents an important predictive parameter for BCVA after macular hole surgery.

[Macular changes in optic disc pits-Optic disc pit maculopathy (ODP-M) : Pathophysiology and possibilities of surgical treatment]

An optic disc pit is a rare congenital abnormality of the optic nerve, which in most cases presents as a unilateral finding. Clinically, a greyish oval excavation is seen, most commonly on the temporal side of the optic nerve disc. The optic disc pit alone normally does not lead to substantial symptoms or functional limitations; however, when a maculopathy with intraretinal and/or subretinal fluid and additional other morphological changes in the macula occur, this leads to a decrease in visual acuity. With spectral domain optical coherence tomography (SDOCT) it is possible to identify the various forms of expression, which show different natural courses. Especially the presence of subretinal fluid and defects in the outer retinal layers have a poor prognosis and have the highest risk for further deterioration. Spontaneous resolution can occur but is rare. Observation is recommended in the first step. In cases of progression or pronounced deterioration, surgical intervention is indicated. Many different techniques have been proposed but there is no gold standard at the moment. Most of the surgical approaches comprise pars plana vitrectomy with peeling of the internal limiting membrane (ILM) and gas endotamponade. Newer methods, such as the ILM flap technique also show good results. Generally, it is important to know that postoperative healing and resorption of the fluid often take a long time period of up to 1 year or even longer.

[Morphology of the vitreoretinal interface in fellow eyes of patients with full thickness macular holes]

PURPOSE

We performed a retrospective, observational clinical study to evaluate the vitreoretinal interface (VRI) in fellow eyes of patients with full thickness macular holes (FTMH) based on spectral domain optical coherence tomography (SD-OCT) examinations.

METHODS

The VRI in fellow eyes of 38 patients with idiopathic FTMH, 6 of which had concomitant vitreomacular traction (VMT) and the VRI of 32 patients with FTMH with complete resolution of VMT were examined by SD-OCT for the presence of vitreomacular adhesion (VMA), VMT and the formation of FTMH, lamellar macular holes (LMH), macular pseudoholes (MPH) or epiretinal membranes (ERM). Patients underwent complete ophthalmic evaluation, including SD-OCT at baseline and follow-up visits. To classify the morphology of the VRI, we used the international vitreomacular traction study classification system by Duker et al. (Ophthalmology 2013), evaluating the baseline SD-OCT data for significant classification parameters, including size of VMA, macular thickness and volume and structural changes of retinal layers.

RESULTS

Of the 38 eyes with FTMH, 2 (5.3%) fellow eyes also showed evidence of FTMH, 5 (13.2%) had isolated VMT while 5 (13.2%) showed formation of ERM, of which 2 demonstrated MPH. In 5 patients (13.2%) showing evidence of VMA and 17 patients (44.7%) with an unremarkable VRI, 22 fellow eyes (57.9%) showed no pathological morphology. Altogether, 16 fellow eyes (42.1%) of patients with FTMH showed pathological changes of the vitreoretinal interface.

CONCLUSION

This high-resolution SD-OCT-based retrospective study showed that fellow eyes of patients with VMT or FTMH were at increased risk of demonstrating pathological changes in the morphology of the VRI.

[Silver coating on tumour prostheses]

BACKGROUND

Modular endoprostheses, so-called "tumour or megaprostheses" are mainly used for limb salvage surgery after resection of malignant soft tissue or a bone tumour. Sometimes, this type of prosthesis is also used for revision surgeries after failed primary joint arthroplasty. Despite continuously improving techniques and quality management systems, periprosthetic infection is one of the most serious complications.

AIM OF THE STUDY

Review of the literature in the PubMed data base with the main focus on silver coatings in joint arthroplasty and their effect on infection rate, outcome and patients' safety.

RESULTS

The current literature shows that there is a beneficial role of silver coatings in megaprostheses in terms of revision rates for septic complications, especially following tumour resection with bad soft tissue coverage or in (multimorbid) high-risk patients, compared to uncoated implants.

DISCUSSION

Based on the results of previous publications examining blood or serum silver concentrations or silver levels in urine, silver coatings do not appear to have side effects, except for local argyria. Continuous monitoring of silver levels in blood or serum is still recommended, and additional long-term studies will be necessary to verify the effectiveness and safety of silver coatings.

Axonal myelin decrease in the splenium in major depressive disorder

The corpus callosum has become a key area of interest for researchers in severe mental illness. Disruptions in fractional anisotropy in the callosum have been reported in schizophrenia and major depressive disorder. No change has been reported in oligodendrocyte density and overall size of the callosum in either illness, suggesting that gross morphology is unchanged, but subtler organisational disruption may exist within this structure. Using high-resolution oil immersion microscopy, we examined the cross-sectional area of the nerve fibre and the axonal myelin sheath; and using standard high-resolution light microscopy, we measured the density of myelinated axons. These measurements were made in the splenium of the corpus callosum. Measures were taken in the sagittal plane in the callosal splenium to contrast with the previous similar examination of the callosal genu. Cases of major depressive disorder had significantly decreased mean myelin cross-sectional area (p = 0.014) per axon in the splenium than in controls or schizophrenia groups. There was no significant change in the density of myelinated axons. The results suggest a clear decrease of myelin in the axons of the callosal splenium in MDD, although this type of neuropathological study is unable to clarify whether this is caused by changes during life or has a developmental origin. In contrast with increased myelin in the callosal genu, this result suggests a longitudinal change in callosal myelination in major depressive disorder not present in normal or schizophrenic brains.

[Intraoperative optical coherence tomography in retinal detachment]

BACKGROUND

Using intraoperative optical coherence tomography (iOCT) can be advantageous during macular surgery and lamellar keratoplasty. It is yet unknown if there is a distinct benefit in its application in retinal detachment surgery.

OBJECTIVE

What can be shown using iOCT during retinal detachment surgery? Can therapeutically relevant decisions be made and do they have a prognostic implication on postoperative results?

METHODS

Based on already published (11 patients/eyes) and our own new data (23 patients/eyes),findings by iOCT during retinal detachment surgery are presented.

RESULTS

Outer retinal corrugations are a frequent feature in iOCT in retinal detachment. These corrugations persist during the application of heavy liquids. Even when the retina seems clinically reattached under the use of perfluoroctane, there is significant subfoveal fluid. Using perfluordecaline, there seems to be less subfoveal fluid. In patients with retinal detachment and macula off situation, subclinical full thickness macular holes seem to be more common than assumed. It is unclear if their incidence is influenced by the use of heavy liquids. They appear to have a negative predictive value regarding postoperative visual acuity.

CONCLUSION

Even if there are no obvious benefits in using iOCT in retinal detachment surgery, this new technique offers deeper insights into the microarchitecture of the detached retina. Further investigations in more patients will show if the use of the iOCT will result in a better prognosis for our patients.

A targeted drug delivery platform for assisting retinal surgeons for treating Age-related Macular Degeneration (AMD)

In this paper we present our latest robotic setup, which has been modified for sub-retinal interventions. The setup consists of: 1) sub-retinal micro cannula with automatic pump; 2) Micromanipulator; 3) patient fixation mechanism and 4) clinically compatible workstation. The primary objective of this work is to allow ophthalmologists to improve administration of substances such as drugs, stem-cells and gene cargos to their desired targets in the sub-retinal microstructures. Such a delivery method will enable effective treatment of Age-related Macular Degeneration (AMD). AMD is the leading cause of blindness in developed countries and as yet there is no efficient treatment. To validate the precision of the system a successful targeted delivery scenario with the proposed setup and using an intra-operative OCT integrated microscope in a clinical environment is presented in this paper.

Haptic interface for robot-assisted ophthalmic surgery

Vitreo-retinal surgery is challenging, as delicate structures have to be manipulated. Eliminating tremor caused by human motions when doing micromanipulation can therefore improve the outcome of such an intervention. An eye surgery robot has been built to overcome this problem. The contribution of this paper is the design of a telemanipulation setup for the robotic system. A telemanipulation setup using a haptic device featuring force feedback as a user interface for controlling a hybrid parallel-serial micromanipulator is designed and developed. The position error control scheme is chosen and different control modes are provided. The output forces of the haptic device are analyzed. The system allows the surgeon to perform precise and comfortable micromanipulation. Nevertheless a way to provide more meaningful force feedback still has to be found.

[Optical coherence tomography in eyes with senile retinoschisis : SD-OCT versus ultrasound examinations and assessment of the vitreoretinal interface]

BACKGROUND

In addition to ocular ultrasonography (US), spectral domain optical coherence tomography (SD-OCT) is available in order to diagnose senile retinoschisis (sRS). SD-OCT also allows for classification of posterior vitreous detachment (PVD) in healthy eyes.

OBJECTIVES

Reevaluation of the value and additional benefit of both imaging procedures. SD-OCT-based evaluation of PVD stages in sRS patients.

MATERIALS AND METHODS

Diagnostic results of 33 eyes in 26 patients with clinical suspicion of sRS were retrospectively analysed. All patients received a SD-OCT and a 10 MHz US examination of the region of interest (RoI). In 32 eyes the PVD stage was classified by SD-OCT using the description by Uchino et al. The vitreous position in peripheral SD-OCT scans with sRS was reviewed.

RESULTS

SD-OCT confirmed sRS in 29 eyes. US examination identified sRS in 26 eyes. In 11 eyes, the examination results of the two methods differed. In 7 eyes sRS was identified by SD-OCT but not by US examination. US examination confirmed sRS in 4 eyes for which SD-OCT scans were not useful. Most cases of sRS were detected in temporal located retinal lesions. There was no significant difference between the results of both imaging procedures regarding the RoI (p = 0.64). SD-OCT provided additional information in 27 eyes. Four eyes did not present PVD. Early and intermediate stages of PVD were detected in 9 eyes, while 19 eyes showed complete PVD. In most cases, the vitreous could not be identified in the SD-OCT scans of the periphery.

CONCLUSIONS

In clinical practice, neither SD-OCT nor US ensure an explicit finding of sRS in each eye with sRS. However, both methods positively complement one another and together they improve image-based diagnosis. All stages of PVD may be found in eyes with sRS. The contribution of the vitreous to the pathogenesis of sRS remains uncertain.

[Maculopathy with optic nerve pits : Morphological criteria in SD-OCT]

PURPOSE

Optic pit is a congenital anomaly with malformation similar to coloboma of the optic disc. The cause of optic pit maculopathy is controversial. We used high resolution OCT to investigate changes in the vitreoretinal and vitreopapillary transition within optic pit eyes.

METHODS

The vitreoretinal and vitreo-papillary transition of 12 eyes was accurately analyzed using SD-OCT. We registered the following criteria: liquefaction of prepapillary vitreous, papillary vitreous traction, discontinuity within the hyaloid cortex and communication spaces between pit and retinal edema.

RESULTS

Communication gaps between pit and retinal edema were identified in 8 eyes. 4 eyes had a papillary vitreous traction. 4 showed a discontinuity in the hyaloid cortex. 2 of the 12 patients showed no maculopathy in SD-OCT. Those patients had an adjacent papillary vitreous without prepapillary liquefaction. However all eyes showed vitreous liquefaction at some stage premacullary or prepapillary.

CONCLUSION

Yet the cause of optic pit maculopathy is not clearly understood. High resolution OCT imaging provides a very detailed assessment of the vitreoretinal transition prepapillary and premacullary, however with limited penetration depth and analyzation of deeper lying structures. Our observations suggest that prepapillary liquefaction and pressure gradients within cerebrospinal and intraokular pressure could be key factors.

Graphical user interface for a robotic workstation in a surgical environment

Surgery using a robotic system has proven to have significant potential but is still a highly challenging task for the surgeon. An eye surgery assistant has been developed to eliminate the problem of tremor caused by human motions endangering the outcome of ophthalmic surgery. In order to exploit the full potential of the robot and improve the workflow of the surgeon, providing the ability to change control parameters live in the system as well as the ability to connect additional ancillary systems is necessary. Additionally the surgeon should always be able to get an overview over the status of all systems with a quick glance. Therefore a workstation has been built. The contribution of this paper is the design and the implementation of an intuitive graphical user interface for this workstation. The interface has been designed with feedback from surgeons and technical staff in order to ensure its usability in a surgical environment. Furthermore, the system was designed with the intent of supporting additional systems with minimal additional effort.

[Ocriplasmin as a treatment option for symptomatic vitreomacular traction with and without macular hole. First clinical experiences]

PURPOSE

To evaluate the resolution rate in patients with symptomatic vitreomacular traction (≤ 1500 μm) with or without macular holes (≤ 400 μm) after therapy with intravitreal ocriplasmin (Jetrea®) injection in a clinical setting.

METHODS

Until now we have prospectively examined 21 eyes of 21 consecutive patients with symptomatic vitreomacular traction with or without macular holes who underwent intravitreal operative injection of 0.1 ml ocriplasmin. The best corrected visual acuity and high-resolution optical coherence tomography (SD-OCT) ultrastructural parameters were measured before injection and again 1, 3 and 4 months after treatment. The numbers of resolved vitreomacular traction and closed macular holes were documented.

RESULTS

Vitreomacular traction was resolved in 15 out of 21 (71 %) eyes. Of the five eyes which initially presented with vitreomacular traction with macular holes, all showed resolution of vitreomacular traction but only two of the macular holes were closed. The average best corrected visual acuity was 0.38 logMAR (± 0.23) at baseline and 0.43 logMAR (± 0.28), 0.38 logMAR (± 0.27) and 0.36 logMAR (± 0.24) 1, 3 and 4 months after injection, respectively. The average foveal thickness was 355.95 μm (± 114.53 μm) at baseline, reducing to 304.61 μm (± 100.91 μm), 308.00 μm (±76.17 μm) and 277.50 μm (± 26.24 μm) after 1, 3 and 4 months, respectively.

CONCLUSION

In this ongoing study there was a high percentage of resolution of vitreomacular traction (71 %) 1 month after intravitreal operative injection of Jetrea® and closure of two out of five macular holes. This was further associated with stabilization of visual acuity and reduction of foveal thickness. Further investigations are necessary to document the effectiveness of the pharmacological vitreolysis in a clinical setting.

Tau protein level in cerebrospinal fluid is increased in patients with early multiple sclerosis

Axonal damage has been proposed as the major substrate of permanent clinical disability in multiple sclerosis. Tau protein, a microtubule-associated protein localised in neuronal axons, may serve as a biochemical surrogate marker to evaluate axonal damage in vivo.We intended to determine the extent of axonal damage in different stages and clinical subtypes of MS by investigating cerebrospinal fluid tau concentrations. Tau was measured using an immunoassay in 35 patients with relapsing—remitting MS, eight patients with secondary progressive MS, nine patients with primary progressive MS, 50 patients with clinically isolated syndrome suggestive of early MS and 46 normal controls. Cerebrospinal fluid tau was significantly elevated in MS compared with normal controls (median 206.0 pg/mL versus152.0 pg/mL;P=0.002). No significant difference among different subtypes of MS could be detected, although highest levels were found in very early disease stages. There was a significant elevation of CSF tau among patients with gadolinium-enhancing brain lesions in magnetic resonance imaging (P=0.02) and a tendency towards higher CSF tau levels in patients with pronounced intrathecal IgG synthesis, supporting the notion that axonal damage is influenced by inflammatory activity.

[Therapeutic Options in Vitreomacular Traction With or Without a Macular Hole]

Treatment is usually indicated for symptomatic vitreomacular traction (VMT) with or without a full thickness macular hole (FTMH) and without spontaneous resolution. Ultrastructural parameters are evaluated by SD-OCT, in order to classify the vitreoretinal interface and to estimate the success rate of treatment. The resolution rate after therapy with intravitreal Jetrea® (Ocriplasmin) is high (up to 70 %) in patients with symptomatic focal vitreomacular traction (≤ 1500 µm) with or without a macular hole (≤ 250 µm) and with no epiretinal membrane (ERM), but depends on the exact baseline analysis. All other patients with idiopathic traction retinopathy should be treated by minimal invasive pars plana vitrectomy (MIVI). Vitreoretinal surgery effectively removes traction and gives a high closure rate of a full thickness macular hole (FTMH, 90 to 100 %). It is now a very safe procedure with few side effects. Despite a low risk profile (cataract, retinal tear etc.) the indication for surgery needs to take the safety profile into account. Therefore vitrectomy is only indicated in symptomatic patients complaining of blurred vision, VA reduction and metamorphopsia. Vitrectomy is also indicated in patients whose treatment by pharmacologic vitreolysis has failed.

HBsAg and anti-HCV screening in elderly hospitalized patients of a German tertiary referral centre

BACKGROUND

Elderly patients are under-represented in hepatitis B and C screening approaches, but may be at increased risk for advanced liver disease. We therefore screened a hospitalized elderly population.

MATERIALS AND METHODS

6011 admissions to the department of internal medicine and neurology within one year were screened for HBsAg and anti-HCV (Elecsys(®)-HBsAg and -anti-HCV). Positive anti-HCV results were confirmed with the INNO-LIA™ assay. HCV-RNA was analyzed by real-time PCR in the case of confirmed positive anti-HCV results, HBV-DNA in the confirmed HBsAg positive individuals.

RESULTS

Patient´s mean age (62.4 years) was 19 years above that of the average German population. The confirmed HBsAg prevalence was 0.6 %. 34 % (n = 12/35) of HBsAg positive cases were newly diagnosed, three of them presented with HBV-DNA levels > 2000 IU/mL. The confirmed anti-HCV prevalence was 0.9 %. 14 % (n = 8/56) of anti-HCV positive patients were previously undiagnosed. HCV-RNA was positive in three of them. In newly diagnosed individuals cirrhosis was present in 1/12 of the HBsAg and in 3/8 of the anti-HCV positive individuals. Compared to non-infected controls, the following risk factors were significantly more frequent in infected patients: (i) HBsAg: sexual exposure (20 % vs. 2 %), blood transfusion before 1992 (13 % vs. 6 %), referrals from nursing homes (10 % vs. 1 %). (ii) Anti-HCV: blood transfusion before 1992 (41 % vs. 6 %), IVDU (25 % vs. 0.5 %), organ transplantation (20 % vs. 5 %), hemodialysis (11 % vs. 3 %).

CONCLUSIONS

HBsAg and anti-HCV were underdiagnosed in a senescent population, however, only few cases presented with advanced liver disease. Referrals from nursing homes were at increased risk for HBV infection.

[Indications for nephron-sparing surgery. Analysis over a 13-year period in the context of changing guidelines]

BACKGROUND

The indications for nephron-sparing surgery have been considerably extended by guideline recommendations in recent years. It remains unclear whether clinical practice still reflects these new guidelines.

OBJECTIVE

In this retrospective, monocentric analysis at a tertiary referral center the indications for partial nephrectomy over a 13-year period were evaluated.

METHODS

In a retrospective database analysis all cases of surgically treated renal masses from 2001 to 2013 were evaluated. Besides demographic, tumor-specific and perioperative variables the development of the surgical technique depending on the tumor stage was evaluated.

RESULTS AND DISCUSSION

The proportion of nephron-sparing surgery cases increased from below 20 % in 2001 to 35 % in 2013 in the entire cohort. For stage T1a tumors, partial nephrectomy increased from approximately 50 % to over 90 % and for T1b tumors it rose from 10 % to 50 %. Logistic regression revealed stage 1 tumors to be predictive of partial nephrectomy over the complete evaluation period. Extending the indications for partial nephrectomy even to higher stages is under discussion but not yet supported by data from prospective, controlled studies.

[Morphologic Patterns on Spectral-Domain Optical Coherence Tomography (SD-OCT) as a Prognostic Indicator in Treatment of Macular Edema Due to Retinal Vein Occlusion]

BACKGROUND

SD-OCT is an important tool in the diagnosis of macular oedema (ME) due to retinal vein occlusion (RVO). Its high resolution makes it possible to distinguish various morphological characteristics and differences. The aim of this study is to evaluate the correlation between morphological patterns and the development of visual acuity (VA) after intravitreal treatment of ME due to RVO.

METHODS

81 patients on intravitreal treatment (dexamethasone: n = 53/ranibizumab: n = 28) due to ME associated with branch and central retinal vein occlusion (

BRVO

n = 38/CRVO: n = 43) were retrospectively reviewed. Preoperative SD-OCT images were analysed by vitreous adhesion, epiretinal membranes, foveal contour, height of intraretinal cystoid spaces, inner and outer segment integrity and presence of subretinal fluid. The influence of these patterns on VA improvement was analysed.

RESULTS

In almost every morphological pattern, the data were highly variable. Therapy was effective, with a medium gain in VA of 9.51 letters ETDRS (dexamethasone: 9.62 letters/ranibizumab: 9.29 letters). The improvement in VA in patients with small intraretinal cystoid spaces (thickness ≤ 250 µm) was 19.44 letters ETDRS, compared to 7.23 letters ETDRS in patients with confluent cystoid spaces (p = 0.009). Patients with a convex fovea exhibited more pronounced reduction in central retinal thickness (CRT) (p = 0.004).

CONCLUSION

Analysis of OCT has concentrated on demonstrating oedema and CRT. Our data indicate that detailed OCT morphology and the size of intraretinal cystoid spaces offer important information about VA prognosis after intravitreal therapy in ME due to RVO.

[Intratympanic injection therapy for therapy refractory acute hearing loss: A safe option for secondary treatment]

BACKGROUND

High-dose corticosteroids are currently recommended for idiopathic sudden sensorineural hearing loss (ISSNHL) treatment. Intratympanic injections (ITI) are of growing importance, especially in cases of therapy resistance. The selection of patients for this procedure in SSNHL has not been adequately examined so far.

STUDY DESIGN

A total of 77 patients with ISSNHL after ineffective systemic pretreatment underwent intratympanic administration of dexamethasone and hyaluronic acid. Improvement after treatment was determined by pure tone audiometry for both ears before and of the treated ear after ITI.

RESULTS

In this study 34 female and 43 male patients with mean age of 57 years showed a pre-ITI hearing loss of 35 dB in the lower frequencies and 69 dB in the higher frequencies. The mean hearing gain was 10 dB and the response rate was 62%. Absolute hearing gain revealed significant improvements at 500 Hz, 1 kHz and 2 kHz. Under inclusion of contralateral thresholds there were hardly any differences up to 4 kHz. In a detailed analysis of responders moderate improvements could be observed even in higher frequencies. Overall, no relevant adverse events occurred.

CONCLUSION

Treatment of ISSNHL resistant to systemic regimens by ITI of steroids provides an option that offers additional prospects of auditory improvement for affected patients. The presented results indicate that these modalities are also valid for patients with pancochlear ISSNHL.

The introduction of a new robot for assistance in ophthalmic surgery

This paper introduces the design and development of a new robotic system to assist surgeons performing ophthalmic surgeries. The robot itself is very compact and similar to an average human hand in size. Its primary application is intraocular micromanipulation in order to overcome the existing challenges in treatment of diseases like Retinal Vein Occlusion (RVO). The novel hybrid mechanism designed for this robot allows microscale motions and is stable in the presence of vibrations common in operation room (OR). The robotic system can be easily integrated into standard operation rooms and does not require modification of conventional surgical tools. This compact microsurgical system is suitable for mounting on the patient's head and thereby, solves the problem of patient motion. The compatibility of the robotic system with a real world surgical setup was evaluated and confirmed in this work.