Negative ERG Research Articles

Macular hole in juvenile X-linked retinoschisis

An 18year-old male with no antecedent of trauma, systemic syndrome or myopia was referred for surgical treatment of a full thickness macular hole in the left eye. A more careful inspection revealed discrete foveal cystic changes in the fellow eye and subtle peripheral depigmented retinal pigment epithelial changes in both eyes. A spectral-domain optical coherence tomography (SD-OCT) scan confirmed, in addition to the full thickness macular hole in the left eye, microcystic spaces in the nuclear layers of both retinae. The diagnosis of X-linked retinoschisis was confirmed with a full field electroretinogram displaying the typical negative ERG. Macular holes are uncommon in the young and those complicating X-linked retinoschisis are rare. This report highlights the importance of investigating the presence of a macular hole in a young patient and illustrates the clinical and SD-OCT clues beyond the foveal center which led to the correct diagnosis of X-linked juvenile retinoschisis.

Abstract 1972: Clinical impact of 6q deletion patterns in prostate cancer.

Abstract Deletions of chromosome 6q12-22 represent the second common deletion in prostate cancer. Although most of these deletions are large and span > 50 megabases, a minimal deleted region containing 3-4 megabases was described at 6q15. MAP3K7 (at 6q15) was suggested as a potential target gene in this area. Based on the hypothesis, that large 6q deletions compromising a multitude of genes may have a different impact on the biology of prostate cancer cells than small circumscribed 6q15 deletions, a tissue microarray (TMA) containing over 7000 prostate cancers was analyzed by fluorescence in situ hybridization (FISH). All cancers were analyzed with probes for 6q12, 6q14, 6q15 (MAP3K7), 6q16, and 6q22. 3888 tumors were interpretable for all 5 probes including 463 (10.6%) showing a 6q deletion. 6q deletions were tightly linked to a negative ERG status with 15.6% deletions in ERG negative and 5.8% deletions in ERG positive cancers (p<0.0001). The frequency of 6q deletions increased with Gleason grade and pT stage. 6q deletions were found in 5.4% of ≤3+3, 10.6% of 3+4, 19.6% of 4+3, and 18.8% of ≥4+4 cancers (p<0.0001). 6q deletions occurred in 9.6% of pT2, 11.5% of pT3a, and 14.8% of pT3b carcinomas (p=0.0160). 6q deletions were also linked to early PSA recurrence (p<0.0001). Remarkably, the clinical outcome varied markedly with deletion size. PSA recurrence was more likely in cancers with 6q12-22 deletions as compared to tumors with 6q14-16 deletions (p<0.0001). Twelve genes located within 6q14-16 were functionally evaluated applying colony formation assays to prostate cell lines BPH1, DU-145, and PC-3. These analyses failed to identify a cell behavior consistent with a role as a tumor suppressor gene for MAP3K7, as well as RRAGD, ANKRD6, LYRM2, MDN1, CASP8AP2, BACH2, COQ3, MANEA, RNGTT, SLC35A1, and MMS22L. In conclusion, the strong impact of the deletion size suggests, that multiple genes on chromosome 6q12-22 might have a tumor suppressive role in prostate cancer and that alterations of more than one of these has an additive adverse effect to cells. Our data do not confirm MAP3K7 as the main target of 6q deletions in prostate cancer Citation Format: Martina Kluth, Nina Amschler, Anna Heinl, Simon Jung, Ronald Simon, Thorsten Schlomm, Guido Sauter, Sarah Jane Pauline Minner. Clinical impact of 6q deletion patterns in prostate cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1972. doi:10.1158/1538-7445.AM2013-1972

Increased Adipogenesis in Cultured Embryonic Chondrocytes and in Adult Bone Marrow of Dominant Negative Erg Transgenic Mice

In monolayer culture, primary articular chondrocytes have an intrinsic tendency to lose their phenotype during expansion. The molecular events underlying this chondrocyte dedifferentiation are still largely unknown. Several transcription factors are important for chondrocyte differentiation. The Ets transcription factor family may be involved in skeletal development. One family member, the Erg gene, is mainly expressed during cartilage formation. To further investigate the potential role of Erg in the maintenance of the chondrocyte phenotype, we isolated and cultured chondrocytes from the rib cartilage of embryos of transgenic mice that express a dominant negative form of Erg (DN-Erg) during cartilage formation. DN-Erg expression in chondrocytes cultured for up to 20 days did not affect the early dedifferentiation usually observed in cultured chondrocytes. However, lipid droplets accumulated in DN-Erg chondrocytes, suggesting adipocyte emergence. Transcriptomic analysis using a DNA microarray, validated by quantitative RT-PCR, revealed strong differential gene expression, with a decrease in chondrogenesis-related markers and an increase in adipogenesis-related gene expression in cultured DN-Erg chondrocytes. These results indicate that Erg is involved in either maintaining the chondrogenic phenotype in vitro or in cell fate orientation. Along with the in vitro studies, we compared adipocyte presence in wild-type and transgenic mice skeletons. Histological investigations revealed an increase in the number of adipocytes in the bone marrow of adult DN-Erg mice even though no adipocytes were detected in embryonic cartilage or bone. These findings suggest that the Ets transcription factor family may contribute to the homeostatic balance in skeleton cell plasticity.

Expression of ERG protein, a prostate cancer specific marker, in high grade prostatic intraepithelial neoplasia (HGPIN): lack of utility to stratify cancer risks associated with HGPIN

What's known on the subject? and What does the study add? High grade prostatic intraepithelial neoplasia is a pre-malignant lesion to prostate cancer and is associated with 20%-25% risk of prostate cancer in subsequent repeat biopsies. ERG is a highly prostate-cancer-specific marker. Expression of ERG is rare in isolated high grade prostatic intraepithelial neoplasia diagnosed in prostate biopsy and is not associated with cancer risk in subsequent repeat biopsies. • To evaluate how often ERG, a highly prostate-cancer-specific marker, is expressed in isolated high grade prostatic intraepithelial neoplasia (HGPIN) by immunohistochemistry. • To study whether a positive ERG immunostain in HGPIN correlates with prostate cancer (PCa) detection in subsequent repeat biopsies. • Patients with initial HGPIN in biopsies and at least one follow-up prostate biopsy were included. • Biopsies with HGPIN were immunostained for ERG. • The ERG staining results were then correlated with the PCa risk in subsequent biopsies. • The mean age of 94 patients was 63 years (range 48-78). A mean of 1.8 (range 1-5) repeat biopsy sessions were carried out at a mean interval of 27.4 months (range 1.5-140). The repeat biopsies showed PCa and non-cancer lesions (benign, HGPIN, atypical glands suspicious for cancer) in 36 patients (38%) and 58 patients (62%) respectively. • ERG immunostain was positive in five (5.3%) biopsies with HGPIN, in which PCa was found in two (40%) subsequent biopsies. Of 89 biopsies with negative ERG staining, PCa was found in 34 (38%) repeat biopsies. The cancer detection rate was not different between ERG positive and negative cases (P= 0.299). • This is the first study to investigate the ERG protein expression in prostate biopsy containing HGPIN only and its use to stratify the cancer risk associated with HGPIN. We found that ERG expression is distinctly uncommon in isolated HGPIN (5.3%). • Positive ERG expression is not associated with increased cancer detection in subsequent repeat biopsies. The use of ERG immunostain in the evaluation and cancer risk stratification of HGPIN is of limited value.

Cancer-associated retinopathy presenting as retinal vasculitis with a negative ERG suggestive of on-bipolar cell pathway dysfunction

A 62-year-old female patient presented to our clinic complaining of a 2month history of shimmering photopsias and floaters. An ocular examination, fluorescein angiography, and electrophysiological testing were obtained that suggested either an inflammatory retinal vasculitis or a paraneoplastic syndrome. Melanoma-associated retinopathy was highly suspected despite the absence of previous history for cutaneous melanoma since an electronegative scotopic ERG was recorded on standard flash electroretinography. Additional investigations revealed the presence of a primary breast tumor with secondary lung and pancreatic metastasis that led to the diagnosis of cancer-associated retinopathy. The patient received chemotherapy and 4months after the initial presentation her visual complaints but also her retinal function showed marked improvement. Cancer-associated retinopathy needs to be considered in patients presenting with retinal vasculitis and electrophysiological testing can tailor the approach in these cases.

Studying electrophysiological characteristics in children with congenital sensory nystagmus‐ case presentations

Abstract Purpose In classification of sensory congenital nystagmus (CN) is important to recognize the underlying retinal or visual pathway dysfunction. The aim was to distinguish ERGs and VEPs charcteristics which may identify among variety of disorders associated with sensory CN. Methods In infants and small children that were ophthalmologically classified as sensory CN were ERGs and VEPs recorded simultaneously in the same session. ERGs were detected without dilated pupils and with skin electrodes. Under darkened laboratory conditions were ERGs recorded to white (cone/rod mediated response) and dim blue (rod mediated response) flash and under lighten room were ERGs recorded to white, red and 30 Hz flicker flash (cone mediated responses). VEPs were recorded from three occipital electrodes to flash and onset stimulation. Results Cases with abnormal ERGs showed: in Leber’s congenital amaurosis were undetectable both rod and cone mediated responses from early infancy; in cone‐rod retinal dystrophy abnormal cone and rod mediated responses progressed in time; in achromatopsia abnormal cone mediated responses did not progress in time; in congenital stationary night blindness a negative ERG did not progress in time. Cases with abnormal VEPs showed: in ocular albinism VEP contralateral asymmetry; in achiasmia VEP ipsilateral asymmetry; in severe optic nerve hypoplasia flash VEP was non‐recordable, while in moderate optic nerve hypoplasia flash and pattern onset VEP findings might not correlate with clinic findings. Conclusion Sensory CN is associated with a variety of disorders affecting the retina, optic nerve, chiasm and electrophysiology may characterize retinal or postretinal pathway dysfunction and therefore help in early diagnosis.

The cis-regulatory system of the tbrain gene: Alternative use of multiple modules to promote skeletogenic expression in the sea urchin embryo

The genomic cis-regulatory systems controlling regulatory gene expression usually include multiple modules. The regulatory output of such systems at any given time depends on which module is directing the function of the basal transcription apparatus, and ultimately on the transcription factor inputs into that module. Here we examine regulation of the Strongylocentrotus purpuratus tbrain gene, a required activator of the skeletogenic specification state in the lineage descendant from the embryo micromeres. Alternate cis-regulatory modules were found to convey skeletogenic expression in reporter constructs. To determine their relative developmental functions in context, we made use of recombineered BAC constructs containing a GFP reporter and of derivatives from which specific modules had been deleted. The outputs of the various constructs were observed spatially by GFP fluorescence and quantitatively over time by QPCR. In the context of the complete genomic locus, early skeletogenic expression is controlled by an intron enhancer plus a proximal region containing a HesC site as predicted from network analysis. From ingression onward, however, a dedicated distal module utilizing positive Ets1/2 inputs contributes to definitive expression in the skeletogenic mesenchyme. This module also mediates a newly discovered negative Erg input which excludes non-skeletogenic mesodermal expression.

Retinal pathway origins of the pattern ERG of the mouse

This study investigated contributions from the retinal On and Off pathways, and the spiking and nonspiking activity of neurons in those pathways to the pattern ERG of the mouse. Light-adapted pattern and ganzfeld ERGs were recorded from anesthetized C57BL/6 mice 3–4 months of age. Recordings were made before and after intravitreal injections of PDA (cis-2,3-piperidine-dicarboxylic acid) to block transmission to hyperpolarizing 2nd order and all 3rd order neurons, TTX (tetrodotoxin) to block Na +-dependent spiking, APB (2-amino-4-phosphonobutyric acid) to block synapses between photoreceptors and ON-bipolar cells, and APB + TTX and PDA + TTX cocktails. The pattern stimuli consisted of 0.05 cy/deg gratings reversing in contrast at 1 Hz, presented at various contrasts (50–90%) and a rod saturating mean luminance. For flash ERGs, brief green ganzfeld flashes were presented on a rod-suppressing green background. Recordings were made 39–42 days after unilateral optic nerve crush (ONC) in a subset of animals in which ganglion cell degeneration was subsequently confirmed in retinal sections. Pattern ERGs were similar in waveform for all contrasts, with a positive wave (P1) peak for 90% contrast around 60 ms on average and maximum trough for a negative wave (N2) around 132 ms after each contrast reversal; amplitudes were greatest for 90% contrast which became the standard stimulus. ONC eliminated or nearly eliminated the pattern ERG but did not affect the major waves of the flash ERG. PDA and TTX both delayed P1 and N2 waves of the pattern ERG, and reduced their amplitudes, with effects of PDA on N2 greater than those of TTX. In the flash ERG, PDA reduced a-wave amplitudes, removed OPs but hardly affected b-wave amplitudes. In contrast, TTX reduced b-wave amplitudes substantially, as previously observed in rat. APB removed P1 of the pattern ERG, but left a negative wave of similar timing and amplitude to N2. In the flash ERG, APB removed the b-wave, producing a negative ERG. Addition of TTX to the APB injection removed most of N2 of the pattern ERG, while other waves of the pattern and flash ERG resembled those after APB alone. Addition of TTX to the PDA injection had little effect on the pattern ERG beyond that of PDA alone, but it prolonged the b-wave of the flash ERG. In conclusion, this study confirmed that a selective lesion of ganglion cells will practically eliminate the pattern ERG. The study also showed that P1 of the mouse pattern ERG is dominated by contributions, mainly spiking, from ON pathway neurons, whereas N2 reflects substantial spiking activity from the OFF pathway as well as nonspiking contributions from both pathways.

The Negative ERG: Clinical Phenotypes and Disease Mechanisms of Inner Retinal Dysfunction

The Negative ERG: Clinical Phenotypes and Disease Mechanisms of Inner Retinal Dysfunction

Autoimmune Retinopathy with RPE Hypersensitivity and ‘Negative ERG’ in X-Linked Hyper-IgM Syndrome

Purpose: To report the clinical, electrophysiological, and immunological features of a patient with X-linked hyper-IgM immunodeficiency syndrome type 1 (HIGM1) accompanied by a novel type of autoimmune retinopathy, including retinal pigment epithelium (RPE) hypersensitivity. Methods: Comprehensive ophthalmological examinations, electrophysiological function testing, and inquiries into the immunological status of a 13-year-old presenting with subacute loss of vision in association with a molecularly confirmed diagnosis of HIGM1 were performed. The patient was genotyped by a PCR-based sequence tag content mapping strategy to define the genetic defect within the causative X-HIM gene TNFSF5. Since conventional allogenic bone marrow transplantation has been reported to cure HIGM1, a peripheral blood stem-cell transplantation was performed. Results: (1) The patient's reduced visual acuity included prolonged dark adaptation and visual field constriction. Electrophysiology revealed a ‘negative ERG’ indicating post-receptoral dysfunction. (2) Initial immunological examination of the patient's serum identified abnormal antibody activity with components of the photoreceptors and the inner nuclear layer. The patient later developed indications of RPE hypersensitivity. A massively reduced light-peak to dark-trough ratio of the EOG slow oscillations (L/D ratio) corresponded to impaired RPE-photoreceptor complex function. (3) Molecular genetic analyses revealed the patient to be nullizygous for the tumor necrosis factor ligand member 5 gene (TNFSF5; CD40LG). A large chromosomal deletion of ∼27.6–32.3 kb in size was identified in Xq26. (4) The transplant with its associated immunomodulation appeared to worsen rather than improve the patient's condition. Conclusions: The fundus appearance and electrophysiological function testing revealed indications of atypical retinal degeneration. However, the clinical course and the serological findings were consistent with those of ocular autoimmunity involving both antiretinal activity and RPE hypersensitivity. In this case, peripheral stem-cell transfusion with its associated chemotherapy failed to benefit the patient's vision; indications of autoimmunity appeared to increase following this treatment.

Prognostic implication of ergonovine echocardiography in patients with near normal coronary angiogram or negative stress test for significant fixed stenosis

Objectives: The goal of this study was to assess the prognostic value of ergonovine echocardiography (Erg Echo) for diagnosis of coronary vasospasm (CVS) in patients without significant fixed coronary stenosis. Material and Methods: Medical records of 650 patients who underwent Erg Echo were reviewed. Before Erg Echo, absence of significant fixed coronary stenosis was confirmed by invasive coronary angiography (CAG) in 316 patients (49%) or by noninvasive confirmation of negative treadmill or normal myocardial perfusion scan in 334 patients (51%). The cardiac events after Erg Echo were tabulated and these included cardiac death, myocardial infarction (MI), readmission due to intractable chest pain. Results: The average age was 54 ± 10 years, with 223 women and 427 men. Erg Echo was positive in 237 patients (36%), for whom long-acting calcium channel blocker and nitrates were prescribed. During follow-up (46 ± 23 months), cardiac events developed in 13% (30 of 237) of the positive Erg Echo group and 3% (14 of 413) of the negative Erg Echo group (P <.001). Incidence of cardiac death was higher in the positive Erg Echo group (3.4% vs 0.7%, P =.022). The 5-year survival rate (93% ± 3% vs 99% ± 1%, P =.013) and event-free survival rate (94% ± 2% vs 77% ± 6%, P <.001) were significantly lower in the positive Erg Echo group. Smoking (hazards ratio 6.3; 95% CI 1.7-23.5) and multivessel spasm (hazards ratio 37.2, 95% CI, 8.1 to 170.4) were independent factors associated with cardiac death and/or MI. Conclusion: Erg Echo for noninvasive diagnosis of CVS in the differential diagnosis of chest pain provides useful prognostic information for patients without significant fixed coronary stenosis and can play a role as a cost-effective diagnostic strategy in these selected patients. (J Am Soc Echocardiogr 2002;15:1346-52.)

The negative response of the flash electroretinogram in glaucoma.

The existence of a negative ERG component following the b-wave has been known for a long time. Recently, in unilateral macaque experimental glaucoma, a negative response in flash electroretinograms under scotopic as well as photopic conditions has been shown to be greatly reduced or absent compared to the healthy fellow eye. The aim of this pilot study was to test whether a late negative electroretinogram component is reduced also in human glaucoma patients under different stimulus conditions. Dark-adapted ganzfeld flash electroretinograms were recorded after 30 min of dark using two test conditions, obtained as optimal in pilot studies on controls. Under the scotopic condition I white Xenon-flashes of intensity 0.53 Log photopic Td s were presented on a low white background of 1.38 Log scotopic Td. Under the more photopic condition II orange flashes of intensity -0.37 Log photopic Td s were presented on a blue-adapting background of 2.5 Log scotopic Td. Nine controls and 18 patients with advanced glaucoma were analyzed. The amplitude of the negative response was not significantly reduced in glaucoma patients (condition I: -28.5+/-23.7 microV; condition II: -25.2+/-19.7 microV) compared to controls (condition I: -41.4+/-36.6 microV; condition II: -31.3+/-26.2 microV). The peak latency of the responses under condition I and II did not differ significantly between patients and controls. Thus, the late negative electroretinogram component in ganzfeld flash electroretinograms obtained under scotopic and more photopic conditions does not seem to distinguish as easy between human controls and glaucoma patients as animal experiments suggest.