Clonal heterogeneity in ER+ breast cancer reveals the proteasome and PKC as potential therapeutic targets

Intratumoral heterogeneity impacts the success or failure of anti-cancer therapies. Here, we investigated the evolution and mechanistic heterogeneity in clonal populations of cell models for estrogen receptor positive breast cancer. To this end, we established barcoded models of luminal breast cancer and rendered them resistant to commonly applied first line endocrine therapies. By isolating single clones from the resistant cell pools and characterizing replicates of individual clones we observed inter- (between cell lines) and intra-tumor (between different clones from the same cell line) heterogeneity. Molecular characterization at RNA and phospho-proteomic levels revealed private clonal activation of the unfolded protein response and respective sensitivity to inhibition of the proteasome, and potentially shared sensitivities for repression of protein kinase C. Our in vitro findings are consistent with tumor-heterogeneity that is observed in breast cancer patients thus highlighting the need to uncover heterogeneity at an individual patient level and to adjust therapies accordingly.

Abrogating GPT2 in triple-negative breast cancer inhibits tumor growth and promotes autophagy

Uncontrolled proliferation and altered metabolic reprogramming are hallmarks of cancer. Active glycolysis and glutaminolysis are characteristic features of these hallmarks and required for tumorigenesis. A fine balance between cancer metabolism and autophagy is a prerequisite of homeostasis within cancer cells. Here we show that glutamate pyruvate transaminase 2 (GPT2), which serves as a pivot between glycolysis and glutaminolysis, is highly upregulated in aggressive breast cancers, particularly the triple-negative breast cancer subtype. Abrogation of this enzyme results in decreased tricarboxylic acid cycle intermediates, which promotes the rewiring of glucose carbon atoms and alterations in nutrient levels. Concordantly, loss of GPT2 results in an impairment of mechanistic target of rapamycin complex 1 activity as well as the induction of autophagy. Furthermore, in vivo xenograft studies have shown that autophagy induction correlates with decreased tumor growth and that markers of induced autophagy correlate with low GPT2 levels in patient samples. Taken together, these findings indicate that cancer cells have a close network between metabolic and nutrient sensing pathways necessary to sustain tumorigenesis and that aminotransferase reactions play an important role in maintaining this balance.

Time-Resolved Profiling Reveals ATF3 as a Novel Mediator of Endocrine Resistance in Breast Cancer

Breast cancer is one of the leading causes of death for women worldwide. Patients whose tumors express Estrogen Receptor α account for around 70% of cases and are mostly treated with targeted endocrine therapy. However, depending on the degree of severity of the disease at diagnosis, 10 to 40% of these tumors eventually relapse due to resistance development. Even though recent novel approaches as the combination with CDK4/6 inhibitors increased the overall survival of relapsing patients, this remains relatively short and there is a urgent need to find alternative targetable pathways. In this study we profiled the early phases of the resistance development process to uncover drivers of this phenomenon. Time-resolved analysis revealed that ATF3, a member of the ATF/CREB family of transcription factors, acts as a novel regulator of the response to therapy via rewiring of central signaling processes towards the adaptation to endocrine treatment. ATF3 was found to be essential in controlling crucial processes such as proliferation, cell cycle, and apoptosis during the early response to treatment through the regulation of MAPK/AKT signaling pathways. Its essential role was confirmed in vivo in a mouse model, and elevated expression of ATF3 was verified in patient datasets, adding clinical relevance to our findings. This study proposes ATF3 as a novel mediator of endocrine resistance development in breast cancer and elucidates its role in the regulation of downstream pathways activities.

Noise patterns in visceral surgical procedures: Analysis of second-by-second dBA data of 599 procedures over the course of one year

The objective of this study is to analyze noise patterns during 599 visceral surgical procedures. Considering work-safety regulations, we will identify immanent noise patterns during major visceral surgeries. Increased levels of noise are known to have negative health impacts. Based on a very fine-grained data collection over a year, this study will introduce a new procedure for visual representation of intra-surgery noise progression and pave new paths for future research on noise reduction in visceral surgery. Digital decibel sound-level meters were used to record the total noise in three operating theatres in one-second cycles over a year. These data were matched to archival data on surgery characteristics. Because surgeries inherently vary in length, we developed a new procedure to normalize surgery times to run cross-surgery comparisons. Based on this procedure, dBA values were adjusted to each normalized time point. Noise-level patterns are presented for surgeries contingent on important surgery characteristics: 16 different surgery types, operation method, day/night time point and operation complexity (complexity levels 1–3). This serves to cover a wide spectrum of day-to-day surgeries. The noise patterns reveal significant sound level differences of about 1 dBA, with the most-common noise level being spread between 55 and 60 dBA. This indicates a sound situation in many of the surgeries studied likely to cause stress in patients and staff. Absolute and relative risks of meeting or exceeding 60 dBA differ considerably across operation types. In conclusion, the study reveals that maximum noise levels of 55 dBA are frequently exceeded during visceral surgical procedures. Especially complex surgeries show, on average, a higher noise exposure. Our findings warrant active noise management for visceral surgery to reduce potential negative impacts of noise on surgical performance and outcome.

miRNA-1246 induces pro-inflammatory responses in mesenchymal stem/stromal cells by regulating PKA and PP2A

The tumor microenvironment (TME) has an impact on breast cancer progression by creating a pro-inflammatory milieu within the tumor. However, little is known about the roles of miRNAs in cells of the TME during this process. We identified six putative oncomiRs in a breast cancer dataset, all strongly correlating with poor overall patient survival. Out of the six candidates, miR-1246 was upregulated in aggressive breast cancer subtypes and expressed at highest levels in mesenchymal stem/stroma cells (MSCs). Functionally, miR-1246 led to a p65-dependent increase in transcription and release of pro-inflammatory mediators IL-6, CCL2 and CCL5 in MSCs, and increased NF-κB activity. The pro-inflammatory phenotype of miR-1246 in MSCs was independent of TNFα stimulations and mediated by direct targeting of the tumor-suppressors PRKAR1A and PPP2CB. In vitro recapitulation of the TME revealed increased Stat3 phosphorylation in breast epithelial (MCF10A) and cancer cells (SK-BR-3, MCF7, T47D) upon incubation with conditioned medium (CM) of MSCs overexpressing miR-1246. Additionally, this stimulation enhanced proliferation of MCF10A cells, increased migration of MDA-MB-231 cells and induced attraction of THP-1 monocytic cells. Our data shows that miR-1246 acts as both key-enhancer of pro-inflammatory responses in MSCs and putative oncomiR in breast cancer, suggesting its influence on cancer-related inflammation and breast cancer progression.

Processing two-dimensional X-ray diffraction and small-angle scattering data in DAWN 2

The Powder Calibration and Processing packages implemented in DAWN 2 provide an automated diffraction-geometry calibration and data processing environment for two-dimensional diffraction experiments. The customizable processing chains permit the execution of data processing steps to convert raw two-dimensional data into meaningful data and diffractograms. The provenance of the processed data is maintained, which guarantees reproducibility and transparency of the data treatment.

A software package for the calibration and processing of powder X-ray diffraction and small-angle X-ray scattering data is presented. It provides a multitude of data processing and visualization tools as well as a command-line scripting interface for on-the-fly processing and the incorporation of complex data treatment tasks. Customizable processing chains permit the execution of many data processing steps to convert a single image or a batch of raw two-dimensional data into meaningful data and one-dimensional diffractograms. The processed data files contain the full data provenance of each process applied to the data. The calibration routines can run automatically even for high energies and also for large detector tilt angles. Some of the functionalities are highlighted by specific use cases.

The highly expressed 5'isomiR of hsa-miR-140-3p contributes to the tumor-suppressive effects of miR-140 by reducing breast cancer proliferation and migration

Background

miRNAs are small noncoding RNA molecules that play an important role in post-transcriptional regulation of gene expression. Length and/or sequence variants of the same miRNA are termed isomiRs. While most isomiRs are functionally redundant compared to their canonical counterparts, the so-called 5’isomiRs exhibit a shifted 5’ end and therefore a shifted seed sequence resulting in a different target spectrum. However, not much is known about the functional relevance of these isoforms.

Results

Analysis of miRNA-seq data from breast cancer cell lines identified six pairs of highly expressed miRNAs and associated 5’isomiRs. Among them, hsa-miR-140-3p was of particular interest because its 5’isomiR showed higher expression compared to the canonical miRNA annotated in miRbase. This miRNA has previously been shown to control stemness of breast cancer cells. miRNAseq data of breast cancer patients (TCGA dataset) showed that both the canonical hsa-miR-140-3p and its 5’isomiR-140-3p were highly expressed in patients’ tumors compared to normal breast tissue. In the current work, we present the functional characterization of 5’isomiR-140-3p and the cellular phenotypes associated with its overexpression in MCF10A, MDA-MB-468 and MDA-MB-231 cell lines in comparison to the canonical hsa-miR-140-3p. Contrary to the effect of the canonical hsa-miR-140-3p, overexpression of the 5’isomiR-140-3p led to a decrease in cell viability. The latter observation was supported by cell cycle analysis, where the 5’isomiR-140-3p but not the hsa-miR-140-3p caused cell cycle arrest in G₀/G₁-phase. Additionally, 5’ismoiR-140-3p overexpression was found to cause a decrease in cell migration in the three cell lines. We identified three novel direct target genes of the 5’isomiR-140-3p; COL4A1, ITGA6 and MARCKSL1. Finally, we have shown that knocking down these genes partially phenocopied the effects of the 5’isomiR-140-4p overexpression, where COL4A1 and ITGA6 knockdown led to reduced cell viability and cell cycle arrest, while MARCKSL1 knockdown resulted in a decrease in the migratory potential of cells.

Conclusions

In summary, this work presents evidence that there is functional synergy between the canonical hsa-miR-140-3p and the newly identified 5’isomiR-140-3p in suppressing growth and progression of breast cancer by simultaneously targeting genes related to differentiation, proliferation, and migration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-016-2869-x) contains supplementary material, which is available to authorized users.

[Non-Arteritic Ischemic Optic Neuropathy (NAION)]

Non-arteritic ischemic optic neuropathy (NAION) is virtually unknown outside ophthalmology. It is characterised by acute unilateral visual loss, no pain on eye movements and virtually always optic disc swelling. Optic disc oedema resolves within 1 to 2 months, leaving behind optic atrophy. Vision hardly improves. NAION is the product of local abnormalities of the vascular supply to the optic nerve and general vascular risk factors. Of these, diabetes, hypertension and especially sleep apnoea syndrome are the most important. Recurrences in the involved eye are rare; contralateral recurrence occurs in approximately 15 % of patients. There is no clear scientific evidence for any specific therapy. However, there is general agreement that it is reasonable to control risk factors.

Pressure-induced inhomogeneous chiral-spin ground state in FeGe

(57)Fe nuclear forward scattering on the chiral magnet FeGe reveals an extremely large precursor phase region above the helimagnetic ordering temperature T(C)(p) and beyond the pressure-induced quantum phase transition at 19 GPa. The decrease of the magnetic hyperfine field ⟨B(hf)⟩ with pressure is accompanied by a large increase of the width of the distribution of ⟨B(hf)⟩, indicating a strong quasistatic inhomogeneity of the magnetic states in the precursor region. Hyperfine fields of the order of 4 T (equivalent to a magnetic moment μ(Fe)≈0.4μ(B)) persist up to 28.5 GPa. No signatures of magnetic order have been found at about 31 GPa. The results, supported by ab initio calculations, suggest that chiral magnetic precursor phenomena, such as an inhomogeneous chiral-spin state, are vastly enlarged due to increasing spin fluctuations as FeGe is tuned to its quantum phase transition.

[Optic neuritis]

Optic neuritis is a frequent neuro-ophthalmological disease in which the diagnosis can be based on just a few symptoms and findings. It is not only important to differentiate from other optic nerve disorders but also to recognise special types of optic neuritis, which is mostly only possible during the course of the disease. This article presents a review of the current state in diagnosis and therapy from the authors' personal point of view.

[Current recommendations on optic neuritis]

BACKGROUND

The diagnostics and therapy of optic neuritis are complex and require interdisciplinary cooperation.

AIM

Compact, up-to-date recommendations for the clinician appear to be desirable.

MATERIAL AND METHODS

A selective literature search including the authors' professional experience was carried out. An algorithm for the practical approach to optic neuritis was derived from the best available evidence.

RESULTS

Our recommendation distinguishes between compulsory and optional investigations. Differential diagnostic cues with regard to atypical optic neuritis and other optic neuropathies are shown. Standard therapy patterns and means of escalation are suggested. Indications for referral are presented.

CONCLUSION

The algorithm suggested in this article provides ophthalmologists with an effective orientation aid for the complete treatment procedure of optic neuritis.

[The influence of printing technology conditions on the accuracy and reproducibility of printed contrast panels for assessing contrast sensitivity]

PURPOSE

Contrast studies can provide important knowledge for treatment decisions before surgery or for assessing the driving ability of professional drivers. Accordingly, high demands are placed on contrast panels to obtain reliable and reproducible results. The aim of the study is to find out if the contrast panels on the market meet the requirements.

METHODS

On the basis of measurement evaluation and schematic presentations potential sources of error can be identified. These sources of error may have a decisive influence on the assessment of contrast vision.

RESULTS

Far-reaching analyses have shown that three parameters can have a significant influence on the accuracy and reproducibility of printed contrast panels. This holds for certain properties of the printing substrate, the type of representation of display element, and the choice of the colourant. Only the correct interaction between the substrate and the print colour effects an angle-independent contrast. A matt substrate is necessary, which has a low difference to the printed contrast element in respect of glow, so that possible angle differences have no influence on the contrast assessment. The contrast elements of a contrast panel vary in brightness. Conventional methods for typographical representation of different brightnesses use the method of screening. This causes undesirable edges, which weaken in particular the lower-contrast elements unintentionally. Use of special colours can avoid this effect. In the visible wavelength range the studied contrast elements have an irregular absorption behaviour. Because of differences between the lighting surroundings, this can lead to a differentiated stimulation of cones in practice. Appropriate colourants have a constant absorption behaviour.

CONCLUSION

To get representative results of contrast studies the production of contrast panels needs more knowledge about the interaction between paper and colour than is typically required for print products. On the basis of a prototype optimisation, approaches are presented in this article.

Notizen: Die Kristallstruktur des Mauritins-A / The Crystal Structure of Mauritine-A

The constitution and conformation of the known cyclopeptide alkaloid mauritine-A were determined by X-ray diffraction methods. All amino acids belong to the L-series, 3-hydroxy proline has trans-configuration. As indicated by the UV-spectrum, the 14-membered ring system is considerably strained.

[Ophthalmology lectures from the students' point of view]

INTRODUCTION

Lectures with many participants are considered inefficient and ophthalmology is seen as "not so important" for those studying medicine. We wondered about the students' view on this subject.

METHODS

During the last lesson of a two-week-series of lectures together with the written test, 337 students of two consecutive semesters received a questionnaire with specific questions concerning ophthalmology lectures.

RESULTS

257 questionnaires (76 %) were returned. The students claimed that the lecture itself contributed most of the knowledge for their later medical practice, more than books, scripts, internet etc. Interactivity was welcome, audience response systems were appreciated. Personal contact to the lecturers was considered less important, a variation of the lecturers was considered advantageous. It would be seen as a serious loss if the ophthalmology lecture were abolished.

CONCLUSION

These results contradict clearly the concept of the unimportance of lectures with many participants and contradict as well tendencies not to teach "small" specialties in separate lectures.

[Pupillary diameter in every day situations]

AIM OF THE STUDY

For the construction of true accommodating intraocular lenses and for refractive surgery a knowledge about pupil diameter in daily life is important. Sufficient data are available only in darkness.

MATERIAL AND METHODS

206 volunteers aged between 18 and 72 years without disorders influencing the pupil have been examined by means of pupillography at two luminance conditions (3 and 30 cd/m2) and 3 fixation distances (5 m, 1 m, 0.33 m).

RESULTS

Pupil size decreases by 0.42 mm per decade with the darker condition and 0.25 mm per decade with brighter light. Fixation change from 5 to 1 m has hardly any influence on pupil size, changing to 0.33 m constricts the pupil by 0.43 mm at dark condition and 0.33 mm at the lighter condition.

CONCLUSION

Luminance has the strongest influence on pupil size, near fixation has hardly any influence down to 1 m. The well-known age relation of pupil size in darkness is also valid for mesopic and photopic conditions. At 3 cd/m2 it was the same as reported in darkness, at 30 cd/m2 it was less in absolute numbers, but relative as compared to young adults it was approximately the same.

[Assessment of mesopic and contrast vision for driving licences: which cut-off values, which methods are appropriate?]

BACKGROUND

Hitherto recommendations and thresholds for contrast tests are available for mesopic but not for photopic methods. While mesopic tests are widespread in ophthalmology, in occupational medicine photopic contrast tests are often used. With regard to the attachment 6 of the German Fahrerlaubnisverordnung (FeV) which is relevant since July 2011 we tested the specificity and sensitivity as well as the test-retest reliability of available test devices and defined cut-off values.

METHODS

We examined patients with medium opacities, healthy volunteers and a sample of employees. Optovist EU, Binoptometer 4P and Pelli-Robson charts with standardised illumination were applied for contrast sensitivity testing. All these methods were compared to the Mesotest II as gold standard. We followed the recommendations of the German Qualitätssicherungs-Kommission der Deutschen Ophthalmologischen Gesellschaft (DOG) for contrast vision testing and definition of cut-off values.

RESULTS

64 patients with cataract (age 42-70 years, median 62 years), 50 pilots (age 40-69 years, median 53.5 years) and 109 employees of a transportation company (age 40-59 years, median 50 years) were included in the trial. All contrast sensitivity tests showed a good sensitivity and specificity (AUC 0.86 to 0.99). For Optovist EU and Binoptometer 4P a threshold of 15 % Weber contrast is recommended for examinations according to FeV. The test-retest reliability was high in all methods with highly significant Pearson correlation coefficients of 0.77 to 0.94 and a repeatability coefficient between 0.08 und 0.4. The standard distance of 1 m common for the Pelli-Robson chart cannot be recommended for FeV examinations, while the results at 3 m distance are comparable to those of the other contrast vision tests. The preliminary cut-off for the Pelli-Robson chart at 3 m distance is 1.65.

CONCLUSIONS

Cut-off values for the lawful assessment of applicants are now available. Both Binoptometer 4P and Optovist EU proved to be appropriate and - as expected due to comparable technical properties - the same cut-off can be recommended. At 1 m distance the Pelli-Robson chart is not sensitive enough. Because the new distance of 3 m for the Pelli-Robson chart was investigated in 55 cataract patients and 10 pilots in this trial, a confirmatory trial for this distance is planned.

[Assessment of contrast vision by the Mars letter contrast sensitivity test - which illumination should be used?]

BACKGROUND

For expert opinions on mesopic and contrast vision as stipulated in the recent version of the German driving licence regulations (2011), a standardised implementation of the relevant test method is crucial. DIN 58220, part 7, regulates the assessment of mesopic vision and the required parameters of evaluation are guaranteed by the respective test instruments. Because no standard exists for photopic contrast vision, it is recommended that it conform to that of DIN EN ISO 8596 for visual acuity. For test equipment with integrated viewing fields, the application of such tests may not be difficult. But if visual charts are used the question of standardised illumination arises. The present paper investigates this question when using the Mars Letter Contrast Sensitivity Test in the light of the recommendations by the producer to use a desk lamp for illumination.

METHODS

The Mars Chart was illuminated by three different commercially available desk lights from different directions at a distance of 50 cm, which is the test distance recommended by the producer. The luminance distribution was measured on the chart at twelve equally distributed test points.

RESULTS

For all conditions, the asymmetric illumination produced by a single light source leads to an extremely inhomogeneous luminance distribution over the chart. Adherence to the tolerance ranges for brightness, as well as the homogeneity of illumination from such light sources is left to chance and a subjective judgment of both parameters is not adequate.

CONCLUSION

Illumination of the Mars Chart with a desk light only does not necessarily satisfy the requirement of reproducible test conditions that is mandatory for expert evaluations. For comparable test outcomes for contrast vision, illumination devices that produce a uniform illumination should be employed.

Visual impairment in stroke patients--a review

Approximately 30% of all stroke patients suffer from post-stroke visual impairment. Hemianopia is the most common symptom, but also neglect, diplopia, reduced visual acuity, ptosis, anisocoria, and nystagmus are frequent. Partial or complete recovery of visual disorders can occur, but many patients suffer permanent disability. This disability is often less evident than impairment of motor and speech functions, but is negatively correlated with rehabilitation outcome and can lead to a significant reduction in day-to-day functioning. To be visually impaired after stroke reduces quality of life and causes social isolation because of difficulties in navigating/orientating in the surroundings. A thorough diagnosis including targeted examination and later follow-up with eye examination and perimetry is essential in order to establish the extent of the visual impairment and to select the best rehabilitation strategy. Patients seem to profit from visual rehabilitation focused on coping strategies.

[Meningiomas. Clinical case examples]

Using four case reports as examples the best treatment is discussed by considering the specific history and magnetic resonance imaging (MRI) findings. In many cases different therapeutic alternatives are possible for treatment of meningiomas.

Complex chiral modulations in FeGe close to magnetic ordering

We report on detailed polarized small-angle neutron scattering on cubic FeGe in magnetic fields applied either along (transverse) the scattering vector or parallel (longitudinal) to the neutron beam. The (H, T) phase diagrams for all principal axes contain a segmented A-phase region just below the onset of magnetic order. Hexagonal Bragg-spot patterns were observed across the entire A-phase region for the longitudinal geometry. Scattering intensity was observed in parts of the A phase for both scattering configurations. Only in a distinct pocket (A(1)) was vanishing scattering intensity found in the transverse geometry.

[Characteristics of pupil function in patients with dissociated vertical divergence]

Dissociated vertical divergence (DVD) is frequently associated with the infantile strabismus syndrome. There are different theories on the pathomechanism of this disorder, but none of them is generally accepted. Some authors believe that the slow upward movement of the covered eye is due to a different illumination of both retinae and consequently an unequal activity of the oculomotor nerve's nuclei. In one hypothesis a predominance of crossing pupillary tract fibres from the pretectal area to motor and parasympathetic nuclei of the oculomotor nerve was supposed. The consequence of this abnormal pathway in the midbrain would be a pronounced contraction anisocoria in patients with DVD. In contraction anisocoria the directly illuminated pupil contracts more strongly than the contralateral pupil without any efferent defect. In a small study we compared direct and indirect pupillary light reflexes in 11 DVD patients and 10 normal subjects. We found no significant differences of contraction anisocoria between the two groups. The results do not support the hypothesis of a different pupillary tract pathway in the midbrain of patients with DVD.

[Managing unexplained visual loss--a "quick guide"]

Optic neuritis and anterior ischaemic optic neuropathy (AION) present with acute visual loss. AION shows a swollen optic disc, in optic neuritis it may be swollen in one third of the patients. Optic neuritis patients complain usually about pain with eye movements. A tumour causes slowly progressive visual loss, mostly painless. In all these cases a relative afferent pupillary defect (RAPD) may be expected. If RAPD is missing, a problem of the optic media (retinoscopy, pinhole test), macular disease (micropsy, improvement with grey filters), amblyopia or non-organic visual loss can be causative. However, it has to be considered that a homonymous visual field defect may be perceived as an unilateral visual loss. Therefore visual field testing is necessary.

[The diagnostic risk of overlooking temporal arteritis]

We report two cases of atypical temporal arteritis. A 73-year-old woman with typical internal (diabetes, hypertony, hypercholesterinemia) and ophthomological (optic disc drusen) risk factors for N-AION reported with an acute unilateral decrease in vision. General symptoms, laboratory analysis and biopsy led to the diagnosis of temporal arteritis and iv steroids were administered. An 83-year-old male patient reported with a sudden unilateral decrease in vision, but did not complain about general symptoms. Laboratory analysis revealed no signs for temporal arteritis, therefore the patient was referred to his internal specialist for evaluation of internal risk factors for N-AION. A few days later the patient reported with a unilateral decrease in vision of the partner eye. This time blood analysis was suggestive of temporal arteritis although no general symptoms were reported. Diagnosis was supported by a biopsy of the temporal artery and steroids were administered. These two cases teach us how dangerously easy temporal arteritis can be overlooked and that we have to take even the slightest hint for temporal arteritis seriously and initiate treatment as early as possible.

[Glaucoma screening by means of pupil campimetry]

BACKGROUND

The aim of the study was to find out if pupillographic assessment of the visual field by means of pupil campimetry can identify glaucomatous visual field defects and as such be used for glaucoma screening purposes.

PATIENTS AND METHODS

20 patients with open angle glaucoma and 30 healthy persons were examined by means of pupil campimetry. All glaucoma patients had a glaucomatous visual field defect in at least one eye. The stimulus pattern consisted of 17 white-light stimuli which were presented within the 30° visual field, particularly in the Bjerrum region. The stimulus diameter was 6°. Each stimulus was presented for 200 ms and the interval between the stimuli was 1800 ms. Three stimulus intensities (16.4 cd/m2; 27.1 cd/m2 and 40.5 cd/m2) were tested. The individual pupil light reaction (PLR) amplitudes at all examined locations in the visual field, their sums and partial sums were compared between both groups by the two-sided two-sample t test. The diagnostic performance of the method in glaucoma diagnosis was evaluated by ROC curves (receiver operating characteristics).

RESULTS

The average PLR at all locations in the visual field was reduced in glaucoma patients compared to healthy persons. The sums of the PLR were reduced in glaucoma patients as well. Significant differences in the PLR were found especially in the central and paracentral visual fields. The best AUC values (area under the curve) were reached with the highest stimulus intensity, the highest AUC value overall was 0.769.

CONCLUSION

Although the difference in PLR between glaucoma patients and the control group was significant, the reached AUC values fell short of being ideal for screening purposes. A surprising finding was that the most central pupil response was reduced by the same amount as that in the Bjerrum region.

Confinement of chiral magnetic modulations in the precursor region of FeGe

We report on magnetic susceptibility and specific heat measurements of the cubic helimagnet FeGe in external magnetic fields and temperatures near the onset of long-range magnetic order at TC = 278.2(3) K. Pronounced anomalies in the field-dependent χac(H) data as well as in the corresponding imaginary part χ''ac(H) reveal a precursor region around TC in the magnetic phase diagram. The occurrence of a maximum at T0 = 279.6 K in the zero-field specific heat data indicates a second-order transition into a magnetically ordered state. A shoulder evolves above this maximum as a magnetic field is applied. The field dependence of both features coincides with crossover lines from the field-polarized to the paramagnetic state deduced from χac(T) at constant magnetic fields. The experimental findings are analyzed within the standard Dzyaloshinskii theory for cubic helimagnets. The remarkable multiplicity of modulated precursor states and the complexity of the magnetic phase diagram near the magnetic ordering are explained by the change of the character of solitonic inter-core interactions and the onset of specific confined chiral modulations in this area.

[Current state of pupil-based diagnostics for glaucomatous optic neuropathy]

There are considerable differences between pupillary reactions to light in glaucoma patients and healthy subjects which can be identified by various techniques. These methods are based on the early asymmetry of the afferent conduction in the visual pathway, on the examination of the visual field by focal light stimuli or on visual stimuli in analogy with multifocal electrophysiological tests. Latest findings in pupillary research also suggest a possible use of the intrinsically photosensitive (melanopsin expressing) retinal ganglion cells in glaucoma diagnostics. The current results of pupillary experiments in glaucoma patients are encouraging for further research in this field because suitable objective screening methods for glaucoma are continually being sought.

[Experience in contrast vision testing]

INTRODUCTION

Since July 2011 driving licensing in Germany requires contrast vision to be tested. Recommendations are available for testing under mesopic conditions only. This study is aimed to provide recommendations for photopic testing.

METHOD

169 persons were tested both under mesopic (Mesotest) and photopic (Optovist) conditions.

RESULTS

With the Mesotest the setting without glare and the requirement to recognize contrast 1:5 or with glare contrast 1:23 proved to be suitable. With the Optovist visual acuity size 0.4 without and 0.25 with glare proved to be adequate, if the requirement is to recognize the limit of 5 %.

DISCUSSION

Not unexpectedly, there is no perfect congruence between the tests. We therefore recommend that the screening methods used in industrial medicine need to be sufficiently sensitive and specific, unfortunately this is met only by some of the conditions supplied with the instruments.

Precursor phenomena at the magnetic ordering of the cubic helimagnet FeGe

We report on detailed magnetic measurements on the cubic helimagnet FeGe in external magnetic fields and temperatures near the onset of long-range magnetic order at T(C)=278.2(3) K. Precursor phenomena display a complex succession of temperature-driven crossovers and phase transitions in the vicinity of T(C). The A-phase region, present below T(C) and fields H<0.5 kOe, is split in several pockets. The complexity of the magnetic phase diagram is theoretically explained by the confinement of solitonic kinklike or Skyrmionic units that develop an attractive and oscillatory intersoliton coupling owing to the longitudinal inhomogeneity of the magnetization.

[Relative afferent pupillary defect in glaucoma]

BACKGROUND

The aim of this retrospective study was to estimate the frequency of relative afferent pupillary defect (RAPD) in glaucoma and whether its occurrence relates to the severity of the visual field defect and its side asymmetry as detected by standard automated perimetry.

PATIENTS AND METHODS

Among patients with primary open angle glaucoma examined at the glaucoma unit of our university eye hospital patients were identified in whom a swinging-flashlight test as part of their routine examination was carried out. The central 30° visual field was examined by means of static perimetry using the Tübinger Automatic Perimeter or the Octopus Perimeter. The visual field findings and their side difference were compared between patients with and without RAPD by means of the Wilcoxon rank-sum test.

RESULTS

After having taken into consideration the inclusion criteria, 100 glaucoma patients were included in the study, 34 of them had an RAPD (34 %). For the visual field analysis only the data of 85 patients, who received the same perimetric strategy, were used. 25 of them had an RAPD (29 %). The calculated visual field scores in patients with RAPD were significantly higher than those in patients without RAPD (p < 0.01), that means their visual field loss was generally more advanced. Also the side difference in visual field of both eyes was significantly greater in patients with RAPD (p < 0.01). A receiver operating characteristics (ROC) curve showed that the side difference in visual field defect is a good predictor for RAPD with an area under curve (AUC) of 0.81.

CONCLUSION

RAPD can be diagnosed in about one third of patients with primary open angle glaucoma. It can be found especially with more advanced visual field defects and visual field defects with greater side asymmetry. Its absence does not mean that there is no visual field defect at all. We advise to include the swinging-flashlight test in glaucoma diagnostics.

[Colour comparison tests in unilateral optic neuropathies]

AIM OF THE STUDY

Colour comparison tests are a subjective supplement to the swinging flashlight test. We have investigated the specificity and sensitivity, compared 3 exactly defined different colours (red, green, blue), and looked for age relationships.

METHOD

101 patient with various unilateral optic neuropathies were compared to 103 age-correlated healthy controls in randomised order by letting the patient evaluate red, green and blue colour charts of 5.5 cm diameter.

RESULTS

The area under the receiver operator characteristics curve was 0.804 for red, 0.821 for green and 0.789 for blue, and for any of the 3 colours 0.835 (at least one colour was seen differently). Best results were obtained when even small differences in colour perception were considered as pathological. 29 healthy controls perceived colours differently in both eyes, 24 of those being older than 50 years. The specificity decreased with age, was significant for green and red, not for blue.

DISCUSSION

There were no significant differences between the 3 colours in all age groups. Evaluation of more than one colour does not increase the sensitivity significantly. Even small differences have to be considered as pathological to obtain the highest possible sensitivity. Test specifity decreases with age.

[Pupillary disorders - diagnosis, diseases, consequences]

Examination of the pupil offers an objective evaluation of visual function as well as the vegetative pathways to the eye. Essential information is gathered within a short time. This makes pupillary inspection a valuable part of the routine ophthalmological, neurological and general medical examinations. Due to the proximity of pupillary pathways to various anatomic structures, pupillary dysfunction can be caused by a variety of disorders, some of which may be life threatening. The ophthalmologist plays a key role in detecting pupillary disorders and in directing further investigations. Therefore, one should have a good knowledge of the diagnostic significance of pupillary function and dysfunction.