Sample records for barrido heidelberg retina

  1. Heidelberg retina tomography II parameters in evaluating high- and normal-pressure glaucoma progression

    Risović Dušica


    Full Text Available Background/Aim. Heidelberg retina tomography II (HRT II haves been employed to quantitatively assess the topography of optic discs in eyes with high-pressure glaucoma (HPG and normal-pressure glaucoma (NPG, in order to determine which of global and segmental optic disc parameters will prove to be most suitable for monitoring the progression of these two conditions. Methods. The results of 73 eyes of 73 patients with HPG and NPG were analyzed in relation to age, refractive error, quality of HRT images and stereometric parameters. Results. A statistically significant difference (p < 0.05 between the global baseline and follow-up results was found in: rim volume, maximum cup depth and cup shape measure (in the HPG group, and C/D ratio, cup volume, rim volume and cup shape measure (in the NPG group. The baseline and follow-up results of the retinal nerve fiber layer in the temporal and inferotemporal sectors show a significant difference in both groups. Conclusion. Several HRT stereometric parameters are useful for monitoring the progression of changes of the optic disc and local retina in eyes with HPG and NPG. Both segmental and global scanning is of importance in glaucoma progression analysis.

  2. Analysis of retinal nerve fibre layer changes in anisometropic amblyopia by Heidelberg retina tomograph

    Objective: To identify if anisometropic amblyopia is associated with changes in optic disk morphology. Methods: The study comprised a total of 80 eyes recruited from Shifa Foundation Community Health Centre and the Pakistan Institute of Medical Sciences, Islamabad between May and October 2012. Anisometropic amblyopia was the only cause of disability (visual acuity >6/12) in amblyopic eyes whereas normal eyes had a best corrected visual acuity of 6/6 and no morbidities. Patients with other causes of amblyopia, co-morbid ocular diseases, and in whom a good-quality image could not be obtained were excluded. Mean retinal nerve fiber layer thickness was analysed using Heidelberg retina tomograph. Analysis of frequency distribution, probability and regression were run on the data collected during the study using SPSS version 15.0. Results: The mean age of the patients was 23.85+-5.85 years. The retinal nerve fibre layer thickness ranged between 0.09mm and 0.35 mm (mean: 0.23mm+-0.07) in amblyopic eyes, and between 0.18mm and 0.36mm (mean: 0.25mm+-0.05) in normal eyes. The difference was not statistically significant (p=0.087). No association was found between the retinal nerve fiber layer thickness or the age and refractive error of patients. Conclusion: The optic disk does not appear to be the site of morphological changes in amblyopia. (author)

  3. Avaliação da autofluorescência do fundo de olho nas distrofias de retina com o aparelho Heidelberg Retina Angiograph2 Evaluation of fundus autofluorescence in hereditary retinal diseases using Heidelberg Retina Angiograph2

    Monique Côco


    Full Text Available OBJETIVOS: Definir características do exame de autofluorescência, verificando sua utilidade no diagnóstico e acompanhamento de distrofias retinianas. MÉTODOS: Participaram do estudo, 28 pacientes, adultos, divididos igualmente em quatro grupos com diagnósticos de doença de Stargardt, distrofia de Cones, retinose pigmentar e voluntários saudáveis para estabelecimento do padrão de normalidade. Em média foram obtidas nove imagens com o filtro para angiofluoresceinografia para a formação da imagem autofluorescente no Heidelberg Retina Angiograph2. As imagens de cada grupo de pacientes foram analisadas para verificar características comuns. RESULTADOS: As imagens fundoscópicas autofluorescentes dos voluntários do grupo controle mostraram área foveal hipoautofluorescente em relação à retina do pólo posterior. As imagens dos portadores de doença de Stargardt, em geral, apresentaram lesão hipoautofluorescente, correspondendo à área macular. As principais alterações da autofluorescência em pacientes com distrofia de cones foram hipoautofluorescência macular com halo hiperautofluorescente. Nos portadores de retinose pigmentar, foram encontrados pigmentos periféricos causando hipoautofluorescência. Na região macular, hipoautofluorescência ou apenas desorganização do pigmento. CONCLUSÃO: O estudo mostrou a existência de padrões de autofluorescência de fundo nas distrofias de retina que permitem o diagnóstico e melhor interpretação da fisiopatogenia destas doenças.PURPOSE: To define characteristics of the fundus autofluorescence examination, verifying usefulness in the diagnosis and care of hereditary retinal diseases. METHODS: 28 patients, adults, divided equally into four groups with diagnoses of Stargardt macular dystrophy, cone dystrophy, retinitis pigmentosa and healthy volunteers for the establishment of the normality pattern. An average of nine images with the filter for fluorescein angiography was obtained

  4. Factors affecting the variability of the Heidelberg Retina Tomograph III measurements in newly diagnosed glaucoma patients Fatores associados com a variabilidade das medidas do Heidelberg Retina Tomograph III em pacientes com glaucoma recém-diagnosticados

    Tiago Santos Prata


    Full Text Available PURPOSE: To determine factors associated with the test-retest variability of optic nerve head (ONH topography measurements with confocal scanning laser ophthalmoscopy (CSLO in newly diagnosed glaucomatous patients. METHODS: Consecutive patients with newly diagnosed primary open-angle glaucoma were prospectively enrolled. Patients presenting with any ocular disease other than glaucoma were excluded. All patients underwent CSLO using the Heidelberg Retina Tomograph III (HRT-III in one randomly selected eye (three consecutive scans; performed by the same examiner. For each Heidelberg Retina Tomograph III parameter, repeatability was assessed using within subject standard deviation (Sw and coefficient of variation (CVw, repeatability coefficient (RC and intraclass correlation coefficient (ICC. Scatter plots and regression lines were constructed to identify which factors influenced test-retest measurement variability. RESULTS: A total of 32 patients were included (mean age, 65.4 ± 13.8 years. Most patients were female (65% and white (50%. Among all Heidelberg Retina Tomograph III parameters evaluated, rim area and mean cup depth had the best measurement repeatability. Vertical cup-to-disc ratio (CDR, as determined by optic disc stereophotograph examination was significantly associated (R²=0.21, p0.14. CONCLUSION: Heidelberg Retina Tomograph III showed good test-retest repeatability for all ONH topographic measurements, mainly for rim area and mean cup depth. Test-retest repeatability seemed to improve with increasing CDR. These findings suggest that HRT-III topographic measurements should be cautiously interpreted when evaluating longitudinally glaucoma patients with early structural damage (small CDR.OBJETIVO: Determinar os fatores associados à variabilidade (teste-reteste das medidas topográficas da cabeça do nervo óptico (CNO utilizando a oftalmoscopia confocal de varredura a laser (CSLO em pacientes com glaucoma recém-diagnosticados. M

  5. Optic nerve head parameters of high-definition optical coherence tomography and Heidelberg retina tomogram in perimetric and preperimetric glaucoma

    Begum, Viquar Unnisa; Addepalli, Uday Kumar; Senthil, Sirisha; Garudadri, Chandra Sekhar; Rao, Harsha Laxmana


    Background: Heidelberg retina tomogram (HRT) and optical coherence tomography (OCT) are two widely used imaging modalities to evaluate the optic nerve head (ONH) in glaucoma. Purpose: To compare the ONH parameters of HRT3 and high-definition OCT (HD-OCT) and evaluate their diagnostic abilities in perimetric and preperimetric glaucoma. Design: Cross-sectional analysis. Methods: 35 control eyes (24 subjects), 21 preperimetric glaucoma eyes (15 patients), and 64 perimetric glaucoma eyes (44 patients) from the Longitudinal Glaucoma Evaluation Study underwent HRT3 and HD-OCT examinations. Statistical Analysis: Agreement between the ONH parameters of HRT and HD-OCT were assessed using Bland-Altman plots. Diagnostic abilities of ONH parameters were evaluated using area under the receiver operating characteristic curves (AUCs), sensitivity at fixed specificity, and likelihood ratios (LR). Results: Optic disc area, vertical cup to disc ratio, and cup volume with HD-OCT were larger than with HRT, while the rim area was smaller with HD-OCT (P 0.10) to the corresponding HRT ONH parameters (0.81-0.95 in perimetric and 0.55-0.72 in preperimetric glaucoma). LRs associated with diagnostic categorization of ONH parameters of both HD-OCT and HRT were associated with larger effects on posttest probability of perimetric compared to preperimetric glaucoma. Conclusions: ONH measurements of HD-OCT and HRT3 cannot be used interchangeably. Though the diagnostic abilities of ONH parameters of HD-OCT and HRT in glaucoma were comparable, the same were significantly lower in preperimetric compared to perimetric glaucoma. PMID:27221679

  6. Optic nerve head analyser and Heidelberg retina tomograph: accuracy and reproducibility of topographic measurements in a model eye and in volunteers.

    Janknecht, P; Funk, J.


    The accuracy and reproducibility of the optic nerve head analyser (ONHA) and the Heidelberg retina tomograph (HRT) were compared and the performance of the HRT in measuring fundus elevations was evaluated. The coefficient of variation of three repeated measurements in a model eye and in volunteers and the relative error in a model eye was calculated. With ONHA measurements the pooled coefficient of variation in volunteers was 9.3% in measuring cup areas and 8.4% in measuring the cup volume. I...

  7. Retina

    ... of the eyeball. Images that come through the eye's lens are focused on the retina. The retina then ... care provider to see through your pupil and lens to the retina. ... If other eye problems block the provider's view of the retina, ...

  8. Evaluation of subjects with a moderate cup to disc ratio using optical coherence tomography and Heidelberg retina tomograph 3: Impact of the disc area

    Fatih Ulas


    Full Text Available Aim: The aim was to evaluate subjects with a moderate cup to disc ratio using optical coherence tomograph (OCT and Heidelberg retina tomograph (HRT 3. Settings and Design: We included 80 patients with early glaucoma and 80 nonglaucomatous subjects with moderate cup/disc ratio (range of 0.5-0.8 to this cross-sectional study. Subjects and Methods: We compared results of color-coded algorithms of HRT 3 (Moorfields regression analysis [MRA] and Glaucoma probability score [GPS] and OCT. All outputs are classified into three categories: Within normal limits (WNLs, borderline and outside normal limits (ONLs. Diagnostic accuracies of algorithms were determined using the highest sensitivity criteria. Results: The sensitivities of global MRA, GPS and OCT were 0.75, 0.925 and 0.725, respectively, in average disc area group and 0.85, 1.0 and 0.425, respectively, in large disc area group. The specificities of global MRA, GPS and OCT were 0.55, 0.15 and 0.85, respectively, in average disc area group and 0.425, 0.025 and 0.80, respectively, in large disc area group. Area under receiver operating characteristic curve (AUROC of global MRA, GPS and OCT were 0.667, 0.617 and 0.792, respectively, in average disc area group and 0.746, 0.576 and 0.627, respectively, in large disc area group. AUROC of global MRA and OCT combination in the average and large disc area groups were 0.828 and 0.825, respectively. Conclusions: In contrast to GPS and OCT algorithms, diagnostic performance of MRA algorithm increased in large disc area group. Combining MRA and OCT algorithms produced satisfactory diagnostic performance in subjects with an average and large disc area.

  9. Corneal Segmentation Analysis Increases Glaucoma Diagnostic Ability of Optic Nerve Head Examination, Heidelberg Retina Tomograph's Moorfield's Regression Analysis, and Glaucoma Probability Score.

    Saenz-Frances, F; Jañez, L; Berrozpe-Villabona, C; Borrego-Sanz, L; Morales-Fernández, L; Acebal-Montero, A; Mendez-Hernandez, C D; Martinez-de-la-Casa, J M; Santos-Bueso, E; Garcia-Sanchez, J; Garcia-Feijoo, J


    Purpose. To study whether a corneal thickness segmentation model, consisting in a central circular zone of 1 mm radius centered at the corneal apex (zone I) and five concentric rings of 1 mm width (moving outwards: zones II to VI), could boost the diagnostic accuracy of Heidelberg Retina Tomograph's (HRT's) MRA and GPS. Material and Methods. Cross-sectional study. 121 healthy volunteers and 125 patients with primary open-angle glaucoma. Six binary multivariate logistic regression models were constructed (MOD-A1, MOD-A2, MOD-B1, MOD-B2, MOD-C1, and MOD-C2). The dependent variable was the presence of glaucoma. In MOD-A1, the predictor was the result (presence of glaucoma) of the analysis of the stereophotography of the optic nerve head (ONH). In MOD-B1 and MOD-C1, the predictor was the result of the MRA and GPS, respectively. In MOD-B2 and MOD-C2, the predictors were the same along with corneal variables: central, overall, and zones I to VI thicknesses. This scheme was reproduced for model MOD-A2 (stereophotography along with corneal variables). Models were compared using the area under the receiver operator characteristic curve (AUC). Results. MOD-A1-AUC: 0.771; MOD-A2-AUC: 0.88; MOD-B1-AUC: 0.736; MOD-B2-AUC: 0.845; MOD-C1-AUC: 0.712; MOD-C2-AUC: 0.838. Conclusion. Corneal thickness variables enhance ONH assessment and HRT's MRA and GPS diagnostic capacity. PMID:26180641

  10. Study on Stereometric Parameters of Optic Nerve Head of Normal, Big-cupped Disk and Glaucomatous Eyes Using Heidelberg Retina Tomograph

    Xing liu; Yunlan Ling; Xiaoping Zheng; Jingjing Huang


    Purpose: To investigate the difference of stereometric parameters of optic nerve head between the normal subjects and patients with big-cupped disk and primary open angle glaucoma(POAG).Methods: Twenty-two cases (44 eyes) of normal subjects, 17 cases (34 eyes) of patients with big-cupped disk and 19 cases (37 eyes) of patients with POAG underwent Heidelberg Retina Tomograph (HRT) examination to get topography images and stereometric parameters of optic nerve head.Results: The stereometric parameters of optic nerve head of the normal, patients with big-cupped disk and POAG were 1) disk area (mm2): 1.995±0.501, 2.407±0.661and 2. 248±0.498;2) cup area (mm2): 0. 573 ±0. 264, 1. 095±0.673 and 1.340±0.516; 3) cup/disk ratio: 0. 257±0.095, 0. 428±0.176 and 0. 589 ±0. 195; 4) rim area (mm2): 1.461±0.328, 1.312±0.418 and 0.905±0.409; 5)cup volume (mm3):0.108±0.073, 0.347±0.346 and 0.550±0.394; 6) rim volume (mm3): 0.421±0.111, 0.378±0.225 and 0.224±0.189;7) mean cup depth (mm): 0.225±0.070,0.327±0.105 and 0.424±0.148; 8) maxim cup depth(mm): 0.630±0.178,0.732±0.170 and 0.871±0.245; 9) cup shape measure (mm): -0.1867±0.09,-0.108±0.068 and -0.02±0.164; 10) mean RNFL thickness (mm): 0.290±0.053, 0.236 ±0.131 and 0.174 ±0.134; 11) RNFL cross sectional area (mm2):1.419±0.332, 1.263±0.606 and 0.920±0.687. Besides, there was no difference of disk area between big cupped disk group and POAG group, no difference of rim area,rim volume and RNFL thickness between normal group and big cupped disk group,statistics analysis showed that there was significant difference of other stereometric parameters between the normal group and big cupped disk group or big cupped disk group and POAG group.Conclusions: There is certain difference of optic nerve head between the normal subjects and big-cupped disk a nd patients with POAG.

  11. 海德堡视网膜断层扫描仪在开角型青光眼诊断中的价值%The evaluation signifcance of Heidelberg retina tomography in primary open angl glaucoma

    李海燕; 张翠荣; 方秀荣; 万晓钢


    目的 评价海德堡视网膜断层扫描仪 (Heidelberg retina tomograph,HRT)在开角型青光眼(primary open angl glaucom,POAG)诊断中的应用价值.方法 对照组98例(98眼)和POAG组36例(36眼)分别行HRT检查,比较各组间视盘结构参数的差异,并用ROC曲线下面积分析不同参数的诊断灵敏度和特异度.结果 对照组与POAG组间杯盘面积比、视杯容积、盘沿容积、视杯形态测量指数及平均视网膜神经纤维层厚度差异均有统计学意义(P<0.05).ROC曲线下面积分析特异度最高的为视杯形态测量指数,灵敏度最高的为平均视网膜神经纤维层厚度.结论 HRT检查对开角型青光眼的诊断有很大帮助.

  12. PANIC at Heidelberg

    Earlier this year in Heidelberg there was PANIC - short for Particle and Nuclei International Conference. This is the new name which has been adopted for a series which in fact began in 1963, the aim being to cover the common ground between the physics of nuclei and of elementary particles

  13. Survival of Salmonella Heidelberg in hummus

    Salmonella Heidelberg is the fourth-most commonly reported Salmonella serotype to cause human illness. There have been several outbreaks and recalls caused by S. Heidelberg in ready to eat foods. Recently, 700 people became ill from ingesting hummus shirazi contaminated with S. Heidelberg. This stud...

  14. Heidelberger Poetikdozentur 2008 - Peter Bieri

    Bieri, Peter; Kopp-Marx, Michaela


    Peter Bieri wurde am 23. Juni 1944 in Bern geboren und wuchs dort auf. Nach der Maturität ging er 1963 für ein Studienjahr nach London. 1964 nahm er ein Studium der Philosophie, Indologie, der Klassischen Philologie und Anglistik an der Universität Heidelberg auf, das er 1971 mit der Dissertation über „Zeit und Zeiterfahrung“ in den Schriften des englischen Philosophen John McTaggart Ellis McTaggart (1866-1925) abschloß. Während seiner Assistenzzeit (u.a. bei Dieter Henrich) ging er nach Berk...

  15. Progress at the Heidelberg EBIT

    Crespo López-Urrutia, J. R.; Braun, J.; Brenner, G.; Bruhns, H.; Dimopoulou, C.; Draganic, I. N.; Fischer, D.; González Martínez, A. J.; Lapierre, A.; Mironov, V.; Moshammer, R.; Soria Orts, R.; Tawara, H.; Trinczek, M.; Ullrich, J.


    Two years after the relocation of the Heidelberg EBIT, several experiments are already in operation. Spectroscopic measurements in the optical region have delivered the most precise reported wavelengths for highly charged ions, in the case of the forbidden transitions of Ar XIV and Ar XV. The lifetimes of the metastable levels involved in those transitions has been determined with an error of less than 0.2%. A new, fully automatized x-ray crystal spectrometer allows systematic measurements with very high precision and reproducibility. Absolute measurements of the Lyman series of H-like ions are currently underway. Dielectronic recombination studies have yielded information on rare processes, as two-electron-one photon transitions in Ar16+, or the interference effects between dielectronic and radiative recombination in Hg77+. The apparatus can now operate at electron beam currents of more than 500 mA, and energies up to 100 keV. A further beam energy increase is planned in the near future. Ions can be extracted from the trap and transported to external experiments. Up to 4 × 107 Ar16+ ions per second can be delivered to a 1 cm diameter target at 10 m distance. Charge-exchange experiments with U64+ colliding with a cold He atomic beam have been carried out, as well as experiments aiming at the optimization of the charge state distribution of the extracted via dielectronic recombination. Two new EBITs, currently in advanced state of construction in Heidelberg, will be used for experiments at the VUV free electron laser at TESLA (Hamburg) and for the charge breeding of short-lived radioactive isotopes at the TRIUMF ISAC facility.

  16. The retina

    van Reyk, David M; Gillies, Mark C; Davies, Michael Jonathan


    A prominent and early feature of the retinopathy of diabetes mellitus is a diffuse increase in vascular permeability. As the disease develops, the development of frank macular oedema may result in vision loss. That reactive oxygen species production is likely to be elevated in the retina, and that...... oxidants by vascular endothelium and leukocytes. There is substantial evidence from animal and clinical studies for both impaired antioxidant defences and increased oxidative damage in the retinae of diabetic subjects that have been, in the case of animal studies, reversible with antioxidant...... supplementation. Whether oxidative damage has a causative role in the pathology of diabetic retinopathy, and thus whether antioxidants can prevent or correct any retinal damage, has not been established, nor has the specific nature of any damaging species been characterised....

  17. Infrared retina

    Krishna, Sanjay; Hayat, Majeed M.; Tyo, J. Scott; Jang, Woo-Yong


    Exemplary embodiments provide an infrared (IR) retinal system and method for making and using the IR retinal system. The IR retinal system can include adaptive sensor elements, whose properties including, e.g., spectral response, signal-to-noise ratio, polarization, or amplitude can be tailored at pixel level by changing the applied bias voltage across the detector. "Color" imagery can be obtained from the IR retinal system by using a single focal plane array. The IR sensor elements can be spectrally, spatially and temporally adaptive using quantum-confined transitions in nanoscale quantum dots. The IR sensor elements can be used as building blocks of an infrared retina, similar to cones of human retina, and can be designed to work in the long-wave infrared portion of the electromagnetic spectrum ranging from about 8 .mu.m to about 12 .mu.m as well as the mid-wave portion ranging from about 3 .mu.m to about 5 .mu.m.

  18. Retina-inspired Filter

    Doutsi, Effrosyni; Fillatre, Lionel; Antonini, Marc; Gaulmin, Julien


    This paper introduces a novel filter which is inspired by the human retina. The human retina consists of three different layers: the Outer Plexiform Layer (OPL), the inner plexiform layer and the ganglionic layer. Our inspiration is the linear transform which takes place in the OPL and has been mathematically described by the neuroscientific model “virtual retina”. This model is the cornerstone to derive the non-separable spatiotemporal OPL retina-inspired filter, briefly renamed retina- insp...

  19. Fabricación reproducible de puntas de barrido para microscopios de efecto túnel

    Rodrigo Bernal; Alba Ávila


    La fabricación reproducible de puntas de barrido para microscopios de efecto túnel es demostrada usando un método electroquímico. Las puntas son hechas a partir de alambre de tungsteno de 0.5 mm de diámetro. Controlando las condiciones de fabricación: la inmersión en la solución electrolítica, rangos de voltaje-corriente y duración del proceso se logra realizar puntas con relaciones de aspecto de 0.68 y radios de punta de 330 nm en el mejor caso./ Reproducible fabrication of Scanning Tunnelin...


    Wen, Rong; Tao, Weng; Li, Yiwen; Sieving, Paul A.


    Ciliary neurotrophic factor (CNTF) is one of the most studied neurotrophic factors for neuroprotection of the retina. A large body of evidence demonstrates that CNTF promotes rod photoreceptor survival in almost all animal models. Recent studies indicate that CNTF also promotes cone photoreceptor survival and cone outer segment regeneration in the degenerating retina and improves cone function in dogs with congenital achromotopsia. In addition, CNTF is a neuroprotective factor and an axogenes...

  1. Proceedings SPRAY 2010, 3.-5. Mai 2010, Heidelberg

    Udo Fritsching


    SPRAY 20109. Workshop über Sprays, Techniken der Fluidzerstäubung und Untersuchungen von SprühvorgängenHeidelberg, 3. - 5. Mai 2010Die Spray-Workshops sollen Ingenieuren und Wissenschaftlern aus Forschung und Industrie Gelegenheit bieten, sich mit aktuellen Problemen und Lösungsansätzen der Fluidzerstäubung, den entsprechenden Messtechniken sowie der physikalischen Modellbildung von Sprayprozessen und deren numerischer Behandlung auseinander zu setzen. Der Workshop Spray 2010 in Heidelberg wa...

  2. Kosmischer Staubsammler - Weltraumsonde Cassini meldet Erfolge nach Heidelberg

    Trieloff, Mario; Srama, Ralf


    Die europäisch-amerikanische Raummission Cassini-Huygens startete im Oktober 1997. Ein Ziel, die Erforschung des Gasplaneten Saturn und seiner Monde. Mit an Bord sind zwölf wissenschaftliche Instrumente. Darunter der Cosmic Dust Analyser, kurz CDA. Ein Staubdetektor, an dessen Konstruktion auch das Max-Planck-Institut für Kernphysik Heidelberg, sowie die Universität Heidelberg beteiligt waren. Bis heute sendet Cassini Daten zur Erde - und die liefern der Wissenschaft neue Erkenntnisse zur Zus...

  3. Fabricación reproducible de puntas de barrido para microscopios de efecto túnel

    Rodrigo Bernal


    Full Text Available La fabricación reproducible de puntas de barrido para microscopios de efecto túnel es demostrada usando un método electroquímico. Las puntas son hechas a partir de alambre de tungsteno de 0.5 mm de diámetro. Controlando las condiciones de fabricación: la inmersión en la solución electrolítica, rangos de voltaje-corriente y duración del proceso se logra realizar puntas con relaciones de aspecto de 0.68 y radios de punta de 330 nm en el mejor caso./ Reproducible fabrication of Scanning Tunneling Microscope tips is carried out following an electrochemical procedure widely reported. Tips are made from 0.5 diameter tungsten wire. Controlling fabrication parameters (immersion in the electrochemical solution, current-voltage ranges, duration of the process, among others we achieve aspect ratios of 0.68 and tip radii of 330 nm in the best case.

  4. UniverCity - Universität Heidelberg. The Future. Since 1386.

    Eitel, Bernhard


    Founded in 1386, Heidelberg University is Germany's oldest university and one of the leading research institutions in Europe. The university's history is inextricably linked to the history and development of the city of Heidelberg.

  5. Deceleration of highly stripped ions by the Heidelberg postaccelerator

    The Heidelberg MP-tandem has been used to produce highly stripped ions of Ssup(14,15,16+), Ni20+ and Br23+ which subsequently were decelerated to 0.15 MeV/amu for atomic physics experiments by the rf-postaccelerator. (orig.)

  6. Heidelberg y Cambridge: historia de dos departamentos universitarios.

    Germán E Berrios


    Full Text Available Discurso de aceptación del Profesor Germán E. Berrios al recibir el Título Honorario de Doctor en Medicina de la Facultad de Medicina de Ruprecht-Karls, Heidelberg, ante el Rector Magnífico y las Autoridades de la Universidad, el 15 de enero de 1998.

  7. Sleeping Beauty. Revitalisation of the old indoor swimming pool Heidelberg; Sleeping Beauty. Revitalisierung des alten Hallenbads Heidelberg

    Paul, Jochen


    Since its closure before nearly 30 years due to safety aspects, the monument protected indoor swimming pool in Heidelberg (Federal Republic of Germany) dilapidated appreciably. Only after moving away of the local council from its demand of the wet use, an investor could be found.

  8. Estudio de la superficie de puntas de gutapercha estandarizadas mediante microscopía electrónica de barrido

    Canalda Sahli, Carlos; Berástegui, Esther


    Se observaron al microscopio electrónico de barrido 45 puntas de gutapercha estandarizadas de los números 30, 40 y 50, de cinco marcas comerciales. En la mayoría de puntas se apreciaron pequeños defectos en su superficie, de escasa importancia clínica. En algunas se evidenciaron anfractuosidades notables que comprometían el ajuste de la punta, especialmente en las de diámetro superior. Se observaron defectos importantes de la conicidad en la porción apical de las puntas y un extremo redondead...

  9. Deutsches Krebsforschungszentrum Heidelberg. Research report 1997/1998

    The Deutsches Krebsforschungszentrum Heidelberg (DKFZ, German Cancer Research Center) publishes alternating every year the 'Research Report' and the 'Wissenschaftlicher Ergebnisbericht' (in German). Both volumes are reports on the present state of research activities of the DKFZ as a National Research Center to the funding federal and state authorities (Federal Republic of Germany, Land (state) Baden-Wuerttemberg). Furthermore they shall inform colleagues and the scientifically interested public. Both reports are structured according to the center's eight research programs. (orig.)

  10. The Heidelberg Catechism: A 16th century quest for unity

    Wim A. Dreyer


    In this contribution the view is presented that the Heidelberg Catechism should be regarded as an attempt to promote unity between 16th century reformers and churches in the Palatinate. This, to some extent, determined the content of the Catechism resulting in some controversial issues receiving less attention. This in turn not only made the Catechism acceptable to a wide spectrum of Reformed Christianity, but also resulted in a creative and unique contribution to Reformed theology, almost a ...

  11. Corpus vitreum, retina og chorioidea biopsi

    Scherfig, Erik Christian Høegh


    oftalmology, biopsy, choroid, corpus vitreum, retina, malignant melanoma, biopsy technic, retinoblastoma......oftalmology, biopsy, choroid, corpus vitreum, retina, malignant melanoma, biopsy technic, retinoblastoma...

  12. Progress with the MPIK/UW-PTMS in Heidelberg

    Diehl, Christoph; Blaum, Klaus; Höcker, Martin; Ketter, Jochen; Pinegar, David B.; Streubel, Sebastian; Van Dyck, Robert S.


    The precise determination of the 3He/3H mass ratio, and hence the tritium β-decay endpoint energy E 0, is of relevance for the measurement of the electron anti-neutrino mass performed by the Karlsruhe Tritium Neutrino experiment (KATRIN). By determining this ratio to an uncertainty of 1 part in 1011, systematic errors of E 0 can be checked in the data analysis of KATRIN. To reach this precision, a Penning Trap Mass Spectrometer was constructed at the University of Washington and has been transferred to the Max Planck Institute for Nuclear Physics in Heidelberg at the end of 2008. Since then it is called MPIK/UW-PTMS. Special design features are the utilization of an external ion source and a double trap configuration. The external Penning ion source efficiently ionizes the helium and tritium gas and can give superior elimination of unwanted ion species compared to the previously utilized in-trap-ionization by electrons from a field-emission point. The design as a double Penning trap allows a faster measurement procedure. This should help to avoid problems resulting from long-term drifts in the experimental conditions. Additionally, the laboratory in Heidelberg was carefully prepared to have very stable environmental conditions. Experimental challenges and the first Heidelberg results with the new spectrometer are presented.

  13. The Retina Algorithm

    CERN. Geneva; PUNZI, Giovanni


    Charge particle reconstruction is one of the most demanding computational tasks found in HEP, and it becomes increasingly important to perform it in real time. We envision that HEP would greatly benefit from achieving a long-term goal of making track reconstruction happen transparently as part of the detector readout ("detector-embedded tracking"). We describe here a track-reconstruction approach based on a massively parallel pattern-recognition algorithm, inspired by studies of the processing of visual images by the brain as it happens in nature ('RETINA algorithm'). It turns out that high-quality tracking in large HEP detectors is possible with very small latencies, when this algorithm is implemented in specialized processors, based on current state-of-the-art, high-speed/high-bandwidth digital devices.

  14. Nuclear physics in Heidelberg in the years 1950 to 1980. Personal recollections

    Weidenmüller, Hans A.


    After World War II, nuclear physics was a central research theme in the Faculty of Physics and Astronomy at Heidelberg University. That tendency was amplified by the founding of the Max-Planck-Institut für Kernphysik in Heidelberg in 1958. The author witnessed these developments as a student and, later, as a member of the Heidelberg Faculty and of the Max-Planck-Institut.

  15. First Results from the Heidelberg Dark Matter Search Experiment

    Baudis, L; Majorovits, B; Schwamm, F; Strecker, H; Klapdor-Kleingrothaus, H V


    The Heidelberg Dark Matter Search Experiment (HDMS) is a new ionization Germanium experiment in a special design. Two concentric Ge crystals are housed by one cryostat system, the outer detector acting as an effective shield against multiple scattered photons for the inner crystal, which is the actual dark matter target. We present first results after successfully running the prototype detector for a period of about 15 months in the Gran Sasso Underground Laboratory. We analyze the results in terms of limits on WIMP-nucleon cross sections and present the status of the full scale experiment, which will be installed in Gran Sasso in the course of this year.

  16. Retina vascular network recognition

    Tascini, Guido; Passerini, Giorgio; Puliti, Paolo; Zingaretti, Primo


    The analysis of morphological and structural modifications of the retina vascular network is an interesting investigation method in the study of diabetes and hypertension. Normally this analysis is carried out by qualitative evaluations, according to standardized criteria, though medical research attaches great importance to quantitative analysis of vessel color, shape and dimensions. The paper describes a system which automatically segments and recognizes the ocular fundus circulation and micro circulation network, and extracts a set of features related to morphometric aspects of vessels. For this class of images the classical segmentation methods seem weak. We propose a computer vision system in which segmentation and recognition phases are strictly connected. The system is hierarchically organized in four modules. Firstly the Image Enhancement Module (IEM) operates a set of custom image enhancements to remove blur and to prepare data for subsequent segmentation and recognition processes. Secondly the Papilla Border Analysis Module (PBAM) automatically recognizes number, position and local diameter of blood vessels departing from optical papilla. Then the Vessel Tracking Module (VTM) analyses vessels comparing the results of body and edge tracking and detects branches and crossings. Finally the Feature Extraction Module evaluates PBAM and VTM output data and extracts some numerical indexes. Used algorithms appear to be robust and have been successfully tested on various ocular fundus images.

  17. Progress and upgrading of the Heidelberg high current injector

    Roland Repnow


    A specialized rf-accelerator system HSI consisting of two RFQ’s and 8 rf seven-gap cavities was built for injection of high intensities of singly charged heavy ions into the Heidelberg heavy ion storage ring TSR. With different ion sources, this system now is used to deliver positive or negative, atomic and molecular ion beams with energies between 150 keV/a.m.u. and 5.3 MeV/a.m.u. final energy. For a future replacement of the MP-tandem-postaccelerator-system the new HSI-accelerator is to be equipped with an ECR source for high intensities of highly charged ions. An advanced commercial ECR source with a 18 GHz rf klystron and an adjustable extraction system for adaption of a wide range of injection energies has been commissioned at the manufacturer and is delivered. Test bench operation presently is in preparation at Heidelberg. A stripper section with an achromatic charge state selector is under construction between injector and postaccelerator. Other ion sources, e.g., for ultra cold $H^{+}_{3}$ molecular ion beams are under development.

  18. [Heidelberger study on psychoanalytic therapy of children and adolescents: methodology].

    Fahrig, H


    In the representative studies published so far on the outcome of analytic child psychotherapy (Dührssen 1964; Fonagy and Target 1996) no techniques of treatment were mentioned. The following paper describes in detail the technique of treatment on which the Heidelberg Study "On the Therapeutic Outcome in Child and Adolescent Psychotherapy" is based, as it developed from 1975 to 1993 at the Heidelberg Institute for Child and Adolescent Psychotherapy. Starting from Piaget's findings that the cognitive faculties of a child up to the age of 11 completely differ from those of an adult and taking into consideration the cerebral information processing and "the intellect pervadet sensory" (Schopenhauer) it is demonstrated that children take their intrapsychic and interpersonal conflicts into analytic play therapy or into role play on analogous levels. Protected by a safe distance from being aware of their conflicts they will on the analogous levels understand, work through, partially solve their conflicts and make use of it in reality without conscious recognition. The term "analogous level" is defined and the manifold possibilities of therapeutic intervention on this level are demonstrated. The efficacy of therapeutic treatment on analogous levels is discussed. PMID:10616294

  19. Low energy electron cooler for the Heidelberg CSR

    The cryogenic storage ring (CSR) is currently under development at MPI-K in Heidelberg. The CSR is an electrostatic ring intended for storing ions in the 20-300 keV energy range (E/Q) in cryogenic environment at temperature down to 2 K. CSR will be equipped with an electron cooler which has to combine cooler and electron target functions. For cooling operation at given ion energies corresponding electron energies are in the range from 160 down to a few eV. Main problems in such operation mode are the decrease of electron beam intensity, the degradation of the electron longitudinal energy spread and the distortion of stored low energy ion trajectories during beams merging. For the CSR a new merging beam section layout together with a photocathode based cold electron source (tested at the Heidelberg TSR) have been proposed. In this paper we present the design of CSR electron cooler including the cryogenic implementation together with numerical calculations of the electron beam longitudinal and transverse energy spread in merged beam section

  20. Estudio de la superficie de limas de endodoncia sometidas a desinfección química mediante microscopia electrónica de barrido

    Navarro Majó, G.; Mateos, M.; J.L. Navarro; Canalda Sahli, Carlos


    Se observaron al microscopio electró nico de barrido 40 limas de endodoncia de acero inoxidable después de ser sometidas a 10 ciclos de desinfección de 10 minutos cada ciclo, sumergidas en diferentes desinfectantes químicos. No se observó corrosión en la superficie de las limas en las circunstancias en que se realizó ese estudio.

  1. Observación del sistema poroso de rocas carbonatadas al microscopio electrónico de barrido

    Alonso, F.


    Full Text Available The pore system of three carbonate rocks is studied through observation of resin and latex casts, under scanning electron microscope. The selected rocks -Hontoria and Seville limestones, and Boñar dolomite- have been broadly employed in the construction of outstanding monuments of the Spanish Historical Heritage. The degree of impregnation achieved by the epoxy resins, according to different procedures, is also checked by means of mercury injection porosimetry techniques. The observation of the pore casts displays, generally, the complexity of the pore systems of these rocks.Se estudia en este trabajo el sistema poroso de tres rocas carbonatadas, a partir de observaciones de moldes de resina y réplicas de látex al microscopio electrónico de barrido. Las rocas seleccionadas -calizas de Hontoria y Sevilla, y dolomía de Boñar- han sido ampliamente utilizadas en la construcción de importantes monumentos del Patrimonio Histórico Español. Se ha comprobado, asimismo, el grado de impregnación alcanzado por las resinas epoxídicas en diferentes procedimientos, a partir de técnicas de porosimetria de inyección de mercurio. Los resultados obtenidos ponen de manifiesto, en general, la complejidad de la estructura porosa de dichas rocas.

  2. Helical tomotherapy. Experiences of the first 150 patients in Heidelberg

    Sterzing, F.; Schubert, K.; Sroka-Perez, G.; Kalz, J.; Debus, J.; Herfarth, K. [Dept. of Radiation Oncology, Univ. of Heidelberg (Germany)


    Background and purpose: helical tomotherapy was introduced into clinical routine at the Department of Radiation Oncology, University Hospital of Heidelberg, Germany, in July 2006. This report is intended to describe the experience with the first 150 patients treated with helical tomotherapy. Patient selection, time effort, handling of daily image guidance with megavoltage (MV) CT, and quality of radiation plans shall be assessed. Patients and methods: between July 2006 and May 2007, 150 patients were treated with helical tomotherapy in the University Hospital of Heidelberg. Mean age was 60 years with a minimum of 30 years and a maximum of 85 years. 79 of these patients received radiotherapy as a part of multimodal treatment pre- or postoperatively, 17 patients received treatment as a combined radiochemotherapy. 76% were treated with curative intent. Radiotherapy sites were central nervous system (n = 7), head and neck (n = 28), thoracic (n = 37), abdominal (n = 58) and skeletal system (n = 20). Most common tumor entities were prostate cancer (n = 28), breast cancer (n = 17), gastrointestinal tumors (n = 19), pharyngeal carcinoma (n = 14), lymphoma (n = 13), metastatic disease (bone n = 14, liver n = 6, lung n = 4, lymph node n = 2), sarcoma (n = 8), malignant pleural mesothelioma (n = 5), ovarian cancer treated with whole abdominal irradiation (n = 4), lung cancer (n = 3), skin malignancies (n = 3), chordoma (n = 2), meningioma (n = 2), one ependymoma and one medulloblastoma treated with craniospinal axis irradiation (n = 2), and others (n = 4). Nine patients were treated with single-fraction radiosurgery, nine with image-guided spinal reirradiation, and twelve patients were treated at multiple targets simultaneously. A pretreatment MV-CT scan was performed in 98.2% of the 3,026 fractions applied. After matching with the kilovoltage planning CT, corrections for translations and rotation around longitudinal axis (roll) were done. Results: mean time on table was 24

  3. Cortical reorganization in recent-onset tinnitus patients by the Heidelberg Model of Music Therapy

    Krick, Christoph M.; Grapp, Miriam; Daneshvar-Talebi, Jonas; Reith, Wolfgang; Plinkert, Peter K; Bolay, Hans Volker


    Pathophysiology and treatment of tinnitus still are fields of intensive research. The neuroscientifically motivated Heidelberg Model of Music Therapy, previously developed by the German Center for Music Therapy Research, Heidelberg, Germany, was applied to explore its effects on individual distress and on brain structures. This therapy is a compact and fast application of nine consecutive 50-min sessions of individualized therapy implemented over 1 week. Clinical improvement and long-term eff...

  4. A Computational Framework for Realistic Retina Modeling.

    Martínez-Cañada, Pablo; Morillas, Christian; Pino, Begoña; Ros, Eduardo; Pelayo, Francisco


    Computational simulations of the retina have led to valuable insights about the biophysics of its neuronal activity and processing principles. A great number of retina models have been proposed to reproduce the behavioral diversity of the different visual processing pathways. While many of these models share common computational stages, previous efforts have been more focused on fitting specific retina functions rather than generalizing them beyond a particular model. Here, we define a set of computational retinal microcircuits that can be used as basic building blocks for the modeling of different retina mechanisms. To validate the hypothesis that similar processing structures may be repeatedly found in different retina functions, we implemented a series of retina models simply by combining these computational retinal microcircuits. Accuracy of the retina models for capturing neural behavior was assessed by fitting published electrophysiological recordings that characterize some of the best-known phenomena observed in the retina: adaptation to the mean light intensity and temporal contrast, and differential motion sensitivity. The retinal microcircuits are part of a new software platform for efficient computational retina modeling from single-cell to large-scale levels. It includes an interface with spiking neural networks that allows simulation of the spiking response of ganglion cells and integration with models of higher visual areas. PMID:27354192

  5. Estudio morfológico del extremo apical inactivo de diversas limas mediante microscopía electrónica de barrido

    Canalda Sahli, Carlos; Berástegui, Esther; Arroyo Bote, Sebastiana; Rais, A.; Brau Aguadé, Esteban


    Diversas firmas han manufacturado limas con el extremo apical inactivo para permitir efectuar la instrumentación de los conductos con una acción rotatoria. El objetivo de este estudio fue evaluar el extremo apical de estas limas (diámetros 30, 40 y 50) mediante microscopía electrónica de barrido, comparándolas con otras limas clásicas. Se observó en todas ellas un extremo apical sin espiras, a diferencia de las limas K convencionales.

  6. Ellipsometry and electronic microscopy of ashes swept of the Popocatepetl volcano; Elipsometria y microscopia electronica de barrido de las cenizas del volcan Popocatepetl

    Munoz, Aaron; Munoz, Rafel; Falcon, Nelson [Universidad de Carabobo, Valencia (Venezuela); Chavira, Enrique [Instituto Nacional de Astrofisica Optica y Electronica, Puebla (Mexico)


    The ellipsometry and the scanning electronic microscopy is applied to the study of the optic properties of Popocatepetl volcano ash in connection with the form, ruggedness and elemental chemical composition of the microparticles, also to argue about the relation with atmospheric conditions. [Spanish] Se aplica la eliposometria y la microscopia electronica de barrido al estudio de las propiedades opticas de las cenizas de volcan Popocatepetl en relacion con la forma, rugosidad y composicion quimica elemental de las microparticulas, destacandose su vinculacion con las condiciones de visibilidad.

  7. Effect of essential oil compound on shedding and colonization of Salmonella enterica serovar Heidelberg in broilers.

    Alali, W Q; Hofacre, C L; Mathis, G F; Faltys, G


    The objectives of this study were to determine the effect of an essential oil blend (EO; carvacrol, thymol, eucalyptol, lemon) administered in drinking water on the performance, mortality, water consumption, pH of crop and ceca, and Salmonella enterica serovar Heidelberg fecal shedding and colonization in broiler birds following Salmonella Heidelberg challenge and feed withdrawal. Chicks were randomly assigned to water treatments containing 0.05, 0.025, or 0.0125% EO or untreated controls. Treatments were administered in drinking water on 0 to 7 and 35 to 42 d. One-half of the chicks were challenged with Salmonella Heidelberg and placed in pens with unchallenged chicks on d 1. Performance, mortality, water consumption, and pH were determined during the 42-d study. Prevalence of Salmonella Heidelberg was determined on drag swabs (0, 14, and 42 d) and in the ceca and crops (42 d). The 0.05% EO administered in drinking water significantly (P feed conversion ratio, and increased weight gain compared with controls. The 0.025% and 0.015% EO in drinking water significantly lowered the feed conversion ratio and increased weight gain compared with controls, but did not significantly reduce Salmonella Heidelberg colonization in the crops. The EO in drinking water did not significantly reduce Salmonella Heidelberg colonization in ceca or fecal shedding in broilers. The EO used in the study may control Salmonella Heidelberg contamination in crops of broilers when administered in drinking water and therefore may reduce the potential for cross-contamination of the carcass when the birds are processed. PMID:23436536

  8. Development of an IH-DTL injector for the Heidelberg cancer therapy project

    Lu, Yuanrong


    Cancer has become one of the most fatal diseases. The Heidelberg Heavy Ion Cancer Therapy (HICAT) has the potential to become an important and efficient treatment method because of its excellent “Bragg peak” characteristics and on-line irradiation control by the PET diagnostics. The dedicated Heidelberg Heavy Ion Cancer Therapy Project includes two ECR ion sources, a RF linear injector, a synchrotron and three treatment rooms. It will deliver 4*10 high 10 protons, or 1*10 high 10 He, or 1*10 ...

  9. Dietary intake of vitamin K and risk of prostate cancer in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Heidelberg).

    Nimptsch, Katharina; Rohrmann, Sabine; Linseisen, Jakob


    BACKGROUND: Anticarcinogenic activities of vitamin K have been observed in various cancer cell lines, including prostate cancer cells. Epidemiologic studies linking dietary intake of vitamin K with the development of prostate cancer have not yet been conducted. OBJECTIVE: We evaluated the association between dietary intake of phylloquinone (vitamin K1) and menaquinones (vitamin K2) and total and advanced prostate cancer in the Heidelberg cohort of the European Prospective Investigation into C...

  10. Complex computation in the retina

    Deshmukh, Nikhil Rajiv

    Elucidating the general principles of computation in neural circuits is a difficult problem requiring both a tractable model circuit as well as sophisticated measurement tools. This thesis advances our understanding of complex computation in the salamander retina and its underlying circuitry and furthers the development of advanced tools to enable detailed study of neural circuits. The retina provides an ideal model system for neural circuits in general because it is capable of producing complex representations of the visual scene, and both its inputs and outputs are accessible to the experimenter. Chapter 2 describes the biophysical mechanisms that give rise to the omitted stimulus response in retinal ganglion cells described in Schwartz et al., (2007) and Schwartz and Berry, (2008). The extra response to omitted flashes is generated at the input to bipolar cells, and is separable from the characteristic latency shift of the OSR apparent in ganglion cells, which must occur downstream in the circuit. Chapter 3 characterizes the nonlinearities at the first synapse of the ON pathway in response to high contrast flashes and develops a phenomenological model that captures the effect of synaptic activation and intracellular signaling dynamics on flash responses. This work is the first attempt to model the dynamics of the poorly characterized mGluR6 transduction cascade unique to ON bipolar cells, and explains the second lobe of the biphasic flash response. Complementary to the study of neural circuits, recent advances in wafer-scale photolithography have made possible new devices to measure the electrical and mechanical properties of neurons. Chapter 4 reports a novel piezoelectric sensor that facilitates the simultaneous measurement of electrical and mechanical signals in neural tissue. This technology could reveal the relationship between the electrical activity of neurons and their local mechanical environment, which is critical to the study of mechanoreceptors

  11. Multidrug-Resistant Salmonella Heidelberg Associated with Mechanically Separated Chicken at a Correctional Facility.

    Taylor, Amanda L; Murphree, Rendi; Ingram, L Amanda; Garman, Katie; Solomon, Deborah; Coffey, Eric; Walker, Deborah; Rogers, Marsha; Marder, Ellyn; Bottomley, Marie; Woron, Amy; Thomas, Linda; Roberts, Sheri; Hardin, Henrietta; Arjmandi, Parvin; Green, Alice; Simmons, Latoya; Cornell, Allyson; Dunn, John


    We describe multidrug-resistant (MDR) Salmonella Heidelberg infections associated with mechanically separated chicken (MSC) served at a county correctional facility. Twenty-three inmates met the case definition. All reported diarrhea, 19 (83%) reported fever, 16 (70%) reported vomiting, 4 (17%) had fever ≥103°F, and 3 (13%) were hospitalized. A case-control study found no single food item significantly associated with illness. Salmonella Heidelberg with an indistinguishable pulsed-field gel electrophoresis pattern was isolated from nine stool specimens; two isolates displayed resistance to a total of five drug classes, including the third-generation cephalosporin, ceftriaxone. MDR Salmonella Heidelberg might have contributed to the severity of illness. Salmonella Heidelberg indistinguishable from the outbreak subtype was isolated from unopened MSC. The environmental health assessment identified cross-contamination through poor food-handling practices as a possible contributing factor. Proper hand-washing techniques and safe food-handling practices were reviewed with the kitchen supervisor. PMID:26540115

  12. Organotypic Culture of Adult Rabbit Retina

    Lye, Ming H.; Jakobs, Tatjana C.; Masland, Richard H.; Koizumi, Amane


    Organotypic culture systems of functional neural tissues are important tools in neurobiological research. Ideally, such a system should be compatible with imaging techniques, genetic manipulation, and electrophysiological recording. Here we present a simple interphase tissue culture system for adult rabbit retina that requires no specialized equipment and very little maintenance. We demonstrate the dissection and incubation of rabbit retina and particle-mediated gene transfer of plasmids enco...

  13. Rod-Cone convergence in the retina.

    Muchungi, Kendi


    Vision enables visual perception of one's environs, as well as self-navigation within space. Objects within our environs are visible by virtue of the fact that they re ect light. To see or have visual perception, this light needs to be converted into an electrical signal. This process is referred to as visual transduction and takes place in the retina. Recently, it has become apparent that the convergence of rod and cone systems in transduction is crucial to enable retina fu...

  14. Radioadaptive Cytoprotective Pathways in the Mouse Retina

    Zanello, Susana B.; Wotring, V.; Theriot, C.; Ploutz-Snyder, R.; Zhang, Y.; Wu, H.


    Exposure to cosmic radiation implies a risk of tissue degeneration. Radiation retinopathy is a complication of radiotherapy and exhibits common features with other retinopathies and neuropathies. Exposure to a low radiation dose elicits protective cellular events (radioadaptive response), reducing the stress of a subsequent higher dose. To assess the risk of radiation-induced retinal changes and the extent to which a small priming dose reduces this risk, we used a mouse model exposed to a source of Cs-137-gamma radiation. Gene expression profiling of retinas from non-irradiated control C57BL/6J mice (C) were compared to retinas from mice treated with a low 50 mGy dose (LD), a high 6 Gy dose (HD), and a combined treatment of 50 mGy (priming) and 6 Gy (challenge) doses (LHD). Whole retina RNA was isolated and expression analysis for selected genes performed by RTqPCR. Relevant target genes associated with cell death/survival, oxidative stress, cellular stress response and inflammation pathways, were analyzed. Cellular stress response genes were upregulated at 4 hr after the challenge dose in LHD retinas (Sirt1: 1.5 fold, Hsf1: 1.7 fold, Hspa1a: 2.5 fold; Hif1a: 1.8 fold, Bag1: 1.7). A similar trend was observed in LD animals. Most antioxidant enzymes (Hmox1, Sod2, Prdx1, Cygb, Cat1) and inflammatory mediators (NF B, Ptgs2 and Tgfb1) were upregulated in LHD and LD retinas. Expression of the pro-survival gene Bcl2 was upregulated in LD (6-fold) and LHD (4-fold) retinas. In conclusion, cytoprotective gene networks activation in the retina suggests a radioadaptive response to a priming irradiation dose, with mitigation of the deleterious effects of a subsequent high dose exposure. The enhancement of these cytoprotective mechanisms has potential value as a countermeasure to ocular alterations caused by radiation alone or in combination with other factors in spaceflight environments.

  15. The Heidelberg Basin Drilling Project - Sedimentology and Stratigraphy of the Quaternary succession

    Ellwanger, Dietrich; Gabriel, Gerald; Hahne, Jürgen; Hoselmann, Christian; Menzies, John; Simon, Theo; Weidenfeller, Michael; Wielandt-Schuster, Ulrike


    Within the context of the Heidelberg Basin Drilling Project (Gabriel et al. 2008), a detailed sediment succession is presented here based upon deep drillings taken at Heidelberg UniNord and Mannheim Käfertal. Sediment structures, and micromorphological and pollen analyses were conducted and used to reconsider some of the climate transitions within the lower Pleistocene. A new and novel scenario is postulated regarding the preservation of Quaternary sediment packages within the Cenozoic Graben environment of the Heidelberg basin. The palynological evidence comprises the periods of warm climate of the Holsteinian (mainly Abies (fir), some Fagus (beech), Pterocarya & Azolla); the Cromerian (Pinus-Picea-QM (pine-spruce-QM)); the Bavelian (Abies, Tsuga (hemlock fir), QM & phases of increased NAP including Pinus); the Waalian (Abies, Tsuga, QM); and the Tiglian (Fagus & early Pleistocene taxa especially Sciadopytis, downward increasing Tertiary taxa). The sediment package was studied both macroscopically and microscopically. Both techniques provide evidence of fluvial, lacustrine and mass movement sedimentary processes. Some include evidence of periglacial processes (silt droplets within fine grained sands indicative of frozen ground conditions). The periglacial structures are often, not always, accompanied by pollen spectra dominated by pine and NAP. E.g. the Tiglian part of the succession shows periglacial sediment structures at its base and top but not in its middle sections. I.e. it appears not as a series of warm and cold phases but rather as a constant warm period with warm-cold-alternations at its bottom and top. All results illustrate sediment preservation in the Heidelberg basin almost throughout the Quaternary. This may be due to tectonic subsidence, but also to compaction by sediment loading of underlying fine sediments (Oligocene to Quaternary) leading to incomplete but virtually continuous sediment preservation (Tanner et al. 2009). References Gabriel, G

  16. Sulfur isotope fractionation by Proteus vulgaris and Salmonella heidelberg during the reduction of thiosulfate

    Proteus vulgris metabolized thiosulfate to H2S. The amount evolved and its sulfur isotope composition identifed it solely with sulfane sulfur. In contrast, Salmonella heidelberg sequentially reduced the sulfane sulfur of S2O32- with slight enrichment of the evolved sulfide in 32S and then reduced the sulfonate sulfur of S2O32- with large isotopic selectivities and an inverse isotopic fractional pattern. The inverse isotope fractionation then reduced the sulfonate sulfur of S2O32- with large isotopic selectivities and an inverse isotopic pattern for the H2S derived from the sulfonate sulfur was almost identical to that observed during the reduction of high concentrations of sulfite by S. heidelberg. (auth)

  17. Lactate Transport and Receptor Actions in Retina

    Kolko, Miriam; Vosborg, Fia; Henriksen, Ulrik L;


    In retina, like in brain, lactate equilibrates across cell membranes via monocarboxylate transporters and in the extracellular space by diffusion, forming a basis for the action of lactate as a transmitter of metabolic signals. In the present paper, we argue that the lactate receptor GPR81, also...... excitability, metabolism and inflammation. Recent publications predict effects of the lactate receptor on neurodegeneration. Neurodegenerative diseases in retina, where the retinal ganglion cells die, notably glaucoma and diabetic retinopathy, may be linked to disturbed lactate homeostasis. Pilot studies...... reveal high GPR81 mRNA in retina and indicate GPR81 localization in Müller cells and retinal ganglion cells. Moreover, monocarboxylate transporters are expressed in retinal cells. We envision that lactate receptors and transporters could be useful future targets of novel therapeutic strategies to protect...

  18. DNA sequence analysis of plasmids from multidrug resistant Salmonella enterica serotype Heidelberg isolates.

    Jing Han

    Full Text Available Salmonella enterica serovar Heidelberg is among the most detected serovars in swine and poultry, ranks among the top five serotypes associated with human salmonellosis and is disproportionately associated with invasive infections and mortality in humans. Salmonella are known to carry plasmids associated with antimicrobial resistance and virulence. To identify plasmid-associated genes in multidrug resistant S. enterica serovar Heidelberg, antimicrobial resistance plasmids from five isolates were sequenced using the 454 LifeSciences pyrosequencing technology. Four of the isolates contained incompatibility group (Inc A/C multidrug resistance plasmids harboring at least eight antimicrobial resistance genes. Each of these strains also carried a second resistance plasmid including two IncFIB, an IncHI2 and a plasmid lacking an identified Inc group. The fifth isolate contained an IncI1 plasmid, encoding resistance to gentamicin, streptomycin and sulfonamides. Some of the IncA/C plasmids lacked the full concert of transfer genes and yet were able to be conjugally transferred, likely due to the transfer genes carried on the companion plasmids in the strains. Several non-IncA/C resistance plasmids also carried putative virulence genes. When the sequences were compared to previously sequenced plasmids, it was found that while all plasmids demonstrated some similarity to other plasmids, they were unique, often due to differences in mobile genetic elements in the plasmids. Our study suggests that Salmonella Heidelberg isolates harbor plasmids that co-select for antimicrobial resistance and virulence, along with genes that can mediate the transfer of plasmids within and among other bacterial isolates. Prevalence of such plasmids can complicate efforts to control the spread of S. enterica serovar Heidelberg in food animal and human populations.

  19. Electron impact ionization measurements at the Heidelberg heavy ion storage ring TSR

    Reliable rate coefficients are needed in order to model the charge state distributions (CSDs) of astrophysical plasmas. We are carrying out electron impact ionization (EII) measurements for astrophysically important ions using the heavy ion Test Storage Ring (TSR) at the Max-Planck Institute for Nuclear Physics in Heidelberg, Germany. These storage ring measurements provide unambiguous data from essentially pure ground-state ion beams.

  20. Kompetenzorientierte Evaluation des adaptiven Schulungskonzepts TUBLIK der Universitätsbibliothek Heidelberg

    Benno Homann; Franziska Kößler


    Im Vergleich zu den Bibliotheken angloamerikanischer Länder verwenden deutsche Bibliotheken bisher kaum sozialwissenschaftliche Evaluationsmethoden, um den Nutzen von Veranstaltungskonzepten für die Steigerung von Informationskompetenz nachzuweisen und die Vermittlungsmethoden zu verbessern. Ansatzpunkte zur Beseitigung dieser Defizite bietet das an der Universitätsbibliothek Heidelberg durchgeführte Projekt TUBLIK (Tutoren- und Blended-Learning-basierte Vermittlung von Informationskompetenz)...

  1. Heidelberger Poetikdozentur 2014 - Wilhelm Genazino: Das vermisste Zuhause: Die verschwundene und doch nicht verlorene Heimat

    Genazino, Wilhelm


    Der Schriftsteller Wilhelm Genazino übernahm zwischen dem 23. Mai und 10. Juni 2014 die Poetikdozentur an der Universität Heidelberg. Im Mittelpunkt des vom Germanistischen Seminar organisierten Veranstaltungsprogramms standen drei öffentliche Poetikvorträge, in denen sich Genazino mit seinem literarischen Schreiben auseinandersetzte. "Das vermisste Zuhause – Die verschwundene und doch nicht verlorene Heimat" war der zweite der drei Vorträge, die der Schriftsteller im Rahmen der Poetikdozentu...

  2. The Heidelberg High Current Injector: A Versatile Injector for Storage Ring Experiments

    von Hahn, R.; Grieser, M.; Repnow, R.; Schwalm, D.; Welsch, C.


    The High Current Injector (HCI) was designed and built as a dedicated single turn injector for the Test Storage Ring in Heidelberg to deliver mainly very high intensities of singly charged Li- and Be-ions for laser cooling experiments. After start of routine operation in 1999 the HCI delivered high quality beams for about 25% of the experiments with very high reliability. Due to the experimental requirements the HCI mutated from a specialized injector to a versatile multipurpose instrumen...

  3. Neues Kardio-MRT-Zentrum am Universitätsklinikum Heidelberg

    Hugo A. Katus; Hopp, Dietmar


    Am Universitätsklinikum Heidelberg wurde in der Klinik für Kardiologie ein neues Kardio-MRT-Zentrum eingerichtet. Dafür wurden zwei neue Magnetresonanztomographen angeschafft. Die Dietmar Hopp Stiftung förderte das neue Zentrum mit drei Millionen Euro. Die Einrichtung wurde jetzt im Beisein des Stifters Dietmar Hopp und des Vorstands des Universitätsklinikums eingeweiht.

  4. Association between socioeconomic and demographic characteristics and utilization of colonoscopy in the EPIC-Heidelberg cohort.

    Hermann, Silke; Friedrich, Susanne; Haug, Ulrike; Rohrmann, Sabine; Becker, Nikolaus; Kaaks, Rudolf


    We aimed to describe the utilization of colonoscopy and its association with sociodemographic characteristics within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg cohort study. We included 15 014 study participants (43% men) of the EPIC-Heidelberg cohort recruited between 1994 and 1998. At baseline recruitment, as well as in the 3-yearly follow-up surveys, study participants completed questionnaires on lifestyle, socioeconomic background variables, health status, and use of medications and medical services, including colonoscopy examinations. The present analyses focused on participants who completed the question on colonoscopy examination in all follow-up rounds. Our results show that by the end of the fourth follow-up round, more than half of all participants of the EPIC-Heidelberg cohort had had a colonoscopy. Colonoscopy was associated with some socioeconomic and demographic characteristics: a positive association with vocational training level as well as overall socioeconomic status level [International Standard Classification of Education (ISCED) classification]. A negative association was found for household size and employment status. Colonoscopy usage increased steeply within the subgroup of participants older than 55 years of age and decreased again within the subgroup of participants older than 75 years of age. Organized colorectal cancer screening should include a written invitation system, to overcome the problem of sociodemographic-related differential awareness of and attendance at colonoscopy examinations. Also, the high proportion of prescreened individuals should be taken into account to avoid unnecessary re-examinations. PMID:25244156

  5. Identification of an early damage of the retina by laser radiation

    The purpose of this investigation has been to find out the retinal threshold energy for a Q-switched Ruby-Laser with an impulse duration of 50 ns. A commercial Laser-Type (Fa. Eltrughs, Heidelberg, West Germany, Type CE 602) was used. For the test rabbits were used general anesthesia: the threshold energy was first determined ophthalmoscopically-enzyme-histochemically. In the first series the coagulation energy accounted between 7 x 10-4 J and 9 x 10-7 J, in the second between 10-6 J and 1.5 x 10-5 J. Clinically the threshold energy was found at a level of 3 - 5 x 10-6 J, clinical-enzyme-histochemically at 1 - 2 x 10-6 J. A theoretical and physical calculation leaded to 0.3 - 3 x 10-6 J. Since the energy measurement varies and due to the different resorption qualities of the human and the rabbit's retina the threshold energy accounts 10-7 J. Labour safety protection should prescribe a threshold energy less than 10-8 J for a Q-switched Ruby-Laser of an impulse duration of 50 ns. (orig.)

  6. Assessment of the optic nerve head parameters using Heidelberg retinal tomography III in preterm children.

    Salem Alshaarawi

    Full Text Available BACKGROUND: Variations in optic nerve head morphology and abnormal retinal vascular pattern have been described in preterm children using digital image analysis of fundus photograph, optical coherence tomograph and serial funduscopy. We aimed to compare the optic nerve head parameters in preterm and term Malay children using Heidelberg Retinal Tomograph III. DESIGN: A cross sectional study. METHODOLOGY/PRINCIPAL FINDINGS: Thirty-two preterm Malay children who were born at up to 32 weeks postconception, and 32 term Malay children aged 8-16 years old were recruited into this cross sectional study, which was conducted in the Hospital Universiti Sains Malaysia, Malaysia from January to December 2011. Their optic nerves were scanned and analyzed using a Heidelberg Retinal Tomography (HRT III (Heidelberg Engineering, Germany. Preterm children showed an increased rim volume (SD (0.56 (0.26 vs 0.44 (0.18 mm(3, respectively, smaller cup shape (SD (0.18 (0.07 vs 0.25 (0.06 mm, respectively, increased height variation contour (SD (0.44 (0.14 vs 0.35 (0.08 mm, respectively, and increased cup depth (SD (0.24 (0.11 vs 0.17 (0.05 mm(3, respectively when compared to their normal peers (p0.05 in our study. CONCLUSIONS/SIGNIFICANCE: Preterm children exhibit different characteristics of optic nerve head parameters with HRT III analysis. Increased cup depth in preterm children suggests a need for close observation and monitoring. It may raise suspicion of pediatric glaucoma when proper documentation of intraocular pressure and clinical funduscopy are unsuccessful in uncooperative children.

  7. Heidelberg Ion Therapy Center (HIT): Initial clinical experience in the first 80 patients

    The Heidelberg Ion Therapy Center (HIT) started clinical operation in November 2009. In this report we present the first 80 patients treated with proton and carbon ion radiotherapy and describe patient selection, treatment planning and daily treatment for different indications. Patients and methods. Between November 15, 2009 and April 15, 2010, 80 patients were treated at the Heidelberg Ion Therapy Center (HIT) with carbon ion and proton radiotherapy. Main treated indications consisted of skull base chordoma (n = 9) and chondrosarcoma (n = 18), malignant salivary gland tumors (n=29), chordomas of the sacrum (n = 5), low grade glioma (n=3), primary and recurrent malignant astrocytoma and glioblastoma (n=7) and well as osteosarcoma (n = 3). Of these patients, four pediatric patients aged under 18 years were treated. Results. All patients were treated using the intensity-modulated rasterscanning technique. Seventy-six patients were treated with carbon ions (95%), and four patients were treated with protons. In all patients x-ray imaging was performed prior to each fraction. Treatment concepts were based on the initial experiences with carbon ion therapy at the Gesellschaft fuer Schwerionenforschung (GSI) including carbon-only treatments and carbon-boost treatments with photon-IMRT. The average time per fraction in the treatment room per patient was 29 minutes; for irradiation only, the mean time including all patients was 16 minutes. Position verification was performed prior to every treatment fraction with orthogonal x-ray imaging. Conclusion. Particle therapy could be included successfully into the clinical routine at the Dept. of Radiation Oncology in Heidelberg. Numerous clinical trials will subsequently be initiated to precisely define the role of proton and carbon ion radiotherapy in radiation oncology.

  8. Heidelberg Ion Therapy Center (HIT): Initial clinical experience in the first 80 patients

    Combs, Stephanie E. (Univ. Hospital of Heidelberg, Dept. of Radiation Oncology, Heidelberg (Germany)), E-mail:; Ellerbrock, Malte; Haberer, Thomas (Heidelberger Ionenstrahl Therapiezentrum (HIT), Im Neuenheimer Feld 450, 69120 Heidelberg (Germany)) (and others)


    The Heidelberg Ion Therapy Center (HIT) started clinical operation in November 2009. In this report we present the first 80 patients treated with proton and carbon ion radiotherapy and describe patient selection, treatment planning and daily treatment for different indications. Patients and methods. Between November 15, 2009 and April 15, 2010, 80 patients were treated at the Heidelberg Ion Therapy Center (HIT) with carbon ion and proton radiotherapy. Main treated indications consisted of skull base chordoma (n = 9) and chondrosarcoma (n = 18), malignant salivary gland tumors (n=29), chordomas of the sacrum (n = 5), low grade glioma (n=3), primary and recurrent malignant astrocytoma and glioblastoma (n=7) and well as osteosarcoma (n = 3). Of these patients, four pediatric patients aged under 18 years were treated. Results. All patients were treated using the intensity-modulated rasterscanning technique. Seventy-six patients were treated with carbon ions (95%), and four patients were treated with protons. In all patients x-ray imaging was performed prior to each fraction. Treatment concepts were based on the initial experiences with carbon ion therapy at the Gesellschaft fuer Schwerionenforschung (GSI) including carbon-only treatments and carbon-boost treatments with photon-IMRT. The average time per fraction in the treatment room per patient was 29 minutes; for irradiation only, the mean time including all patients was 16 minutes. Position verification was performed prior to every treatment fraction with orthogonal x-ray imaging. Conclusion. Particle therapy could be included successfully into the clinical routine at the Dept. of Radiation Oncology in Heidelberg. Numerous clinical trials will subsequently be initiated to precisely define the role of proton and carbon ion radiotherapy in radiation oncology.

  9. Extended-Spectrum Cephalosporin-Resistant Salmonella enterica serovar Heidelberg Strains, the Netherlands1

    Geurts, Yvon; Dierikx, Cindy M.; Brouwer, Michael S.M.; Kant, Arie; Wit, Ben; Heymans, Raymond; van Pelt, Wilfrid; Mevius, Dik J.


    Extended-spectrum cephalosporin-resistant Salmonella enterica serovar Heidelberg strains (JF6X01.0022/XbaI.0251, JF6X01.0326/XbaI.1966, JF6X01.0258/XbaI.1968, and JF6X01.0045/XbaI.1970) have been identified in the United States with pulsed-field gel electrophoresis. Our examination of isolates showed introduction of these strains in the Netherlands and highlight the need for active surveillance and intervention strategies by public health organizations. PMID:27314180

  10. Extended-Spectrum Cephalosporin-Resistant Salmonella enterica serovar Heidelberg Strains, the Netherlands(1).

    Liakopoulos, Apostolos; Geurts, Yvon; Dierikx, Cindy M; Brouwer, Michael S M; Kant, Arie; Wit, Ben; Heymans, Raymond; van Pelt, Wilfrid; Mevius, Dik J


    Extended-spectrum cephalosporin-resistant Salmonella enterica serovar Heidelberg strains (JF6X01.0022/XbaI.0251, JF6X01.0326/XbaI.1966, JF6X01.0258/XbaI.1968, and JF6X01.0045/XbaI.1970) have been identified in the United States with pulsed-field gel electrophoresis. Our examination of isolates showed introduction of these strains in the Netherlands and highlight the need for active surveillance and intervention strategies by public health organizations. PMID:27314180

  11. Tests of a Laser Ion Source at the Heidelberg Electron Beam Ion Trap

    Mironov, V; Trinczek, M.; Werdich, A.; González Martínez, A.; Guo, P; X. Zhang; Braun, J.; Crespo López-Urrutia, J.; Höhr, C.; Ullrich, J.


    A laser ion source (LIS) has been designed and successfully tested for loading the Heidelberg electron beam ion trap (H-EBIT) with ions of practically all solid-state elements. A pulsed YAG:Nd3þ laser (30 mJ, 8 ns) is used to produce plasma from a solid target. Lowly charged ions are extracted from the plasma and accelerated by a short high-voltage pulse, generating a pulsed ion beam with energy of up to 6 keV per charge. The ion beam is transported into the EBIT, decelerated and captured wit...

  12. Optic Disc Imaging by Heidelberg Retinal Tomogram in Congenital Optic Disc Anomaly

    Kunjam Vallam; Sekhar G


    We evaluated two cases of congenital optic disc anomaly with the Heidelberg Retinal Tomograph (HRT) that could be mistaken for glaucomatous optic disc. One was an optic disc coloboma with a visual field defect and the other had an optic disc pit without a visual field defect. HRT was abnormal only in the eye with optic disc pit with normal fields. While HRT can be a valuable adjunct to disc evaluation and follow-up, it cannot be used in isolation in the differentiation of abnormal from normal...

  13. Evolution of liver transplantation at the University of Heidelberg: interventions influencing patient referral.

    Schmied, Bruno Martin; Mehrabi, Arianeb; Schallert, Claudia; Schemmer, Peter; Sauer, Peter; Encke, Jens; Uhl, Waldemar; Friess, Helmut; Kraus, Thomas W; Büchler, Markus W; Schmidt, Jan


    In Heidelberg, liver transplantation was first performed in 1987. In this article, we report our experience with an interdisciplinary approach (intervention) to improve the internal and external acceptance of the liver transplantation program. Formation of a transplant team and interdisciplinary standard setting of pre-, peri-, and postoperative protocols significantly stimulated this process. Involvement of the referring doctors in patient's treatment by transferring competencies enhanced patients referral to our center and increased the numbers of patients on the waiting list, an indispensable factor for organ allocation by Eurotransplant and transplantation. Involvement of patient organizations increased patient acceptance in the program. PMID:16286894

  14. Computational adaptive optics of the human retina

    South, Fredrick A.; Liu, Yuan-Zhi; Carney, P. Scott; Boppart, Stephen A.


    It is well known that patient-specific ocular aberrations limit imaging resolution in the human retina. Previously, hardware adaptive optics (HAO) has been employed to measure and correct these aberrations to acquire high-resolution images of various retinal structures. While the resulting aberration-corrected images are of great clinical importance, clinical use of HAO has not been widespread due to the cost and complexity of these systems. We present a technique termed computational adaptive optics (CAO) for aberration correction in the living human retina without the use of hardware adaptive optics components. In CAO, complex interferometric data acquired using optical coherence tomography (OCT) is manipulated in post-processing to adjust the phase of the optical wavefront. In this way, the aberrated wavefront can be corrected. We summarize recent results in this technology for retinal imaging, including aberration-corrected imaging in multiple retinal layers and practical considerations such as phase stability and image optimization.

  15. TRPM3 expression in mouse retina.

    R Lane Brown

    Full Text Available Transient receptor potential (TRP channels constitute a large family of cation permeable ion channels that serve crucial functions in sensory systems by transducing environmental changes into cellular voltage and calcium signals. Within the retina, two closely related members of the melastatin TRP family, TRPM1 and TRPM3, are highly expressed. TRPM1 has been shown to be required for the depolarizing response to light of ON-bipolar cells, but the role of TRPM3 in the retina is unknown. Immunohistochemical staining of mouse retina with an antibody directed against the C-terminus of TRPM3 labeled the inner plexiform layer (IPL and a subset of cells in the ganglion cell layer. Within the IPL, TRPM3 immunofluorescence was markedly stronger in the OFF sublamina than in the ON sublamina. Electroretinogram recordings showed that the scotopic and photopic a- and b-waves of TRPM3(-/- mice are normal indicating that TRPM3 does not play a major role in visual processing in the outer retina. TRPM3 activity was measured by calcium imaging and patch-clamp recording of immunopurified retinal ganglion cells. Application of the TRPM3 agonist, pregnenolone sulfate (PS, stimulated increases in intracellular calcium in ~40% of cells from wild type and TRPM1(‑/‑ mice, and the PS-stimulated increases in calcium were blocked by co-application of mefenamic acid, a TRPM3 antagonist. No PS-stimulated changes in fluorescence were observed in ganglion cells from TRPM3(-/- mice. Similarly, PS-stimulated currents that could be blocked by mefenamic acid were recorded from wild type retinal ganglion cells but were absent in ganglion cells from TRPM3-/- mice.

  16. Heidelberg standard examination” and “Heidelberg standard procedures” – Development of faculty-wide standards for physical examination techniques and clinical procedures in undergraduate medical education

    Nikendei, C.; Ganschow, P.; Groener, J. B.; Huwendiek, S.; Köchel, A.; Köhl-Hackert, N.; Pjontek, R.; Rodrian, J.; Scheibe, F.; Stadler, A.-K.; Steiner, T.; Stiepak, J.; Tabatabai, J.; Utz, A.; Kadmon, M.


    The competent physical examination of patients and the safe and professional implementation of clinical procedures constitute essential components of medical practice in nearly all areas of medicine. The central objective of the projects “Heidelberg standard examination” and “Heidelberg standard procedures”, which were initiated by students, was to establish uniform interdisciplinary standards for physical examination and clinical procedures, and to distribute them in coordination with all clinical disciplines at the Heidelberg University Hospital. The presented project report illuminates the background of the initiative and its methodological implementation. Moreover, it describes the multimedia documentation in the form of pocketbooks and a multimedia internet-based platform, as well as the integration into the curriculum. The project presentation aims to provide orientation and action guidelines to facilitate similar processes in other faculties.

  17. Dimensions of the foveal avascular zone using the Heidelberg retinal angiogram-2 in normal eyes

    John Deepa


    Full Text Available Purpose: The purpose was to study the dimensions of the foveal avascular zone (FAZ using Heidelberg Retinal Angiogram-2 (HRA-2; Heidelberg Engineering GmBH, Dossenheim, Germany. Materials and Methods: An observational study of the FAZ area and circumference was done with fundus fluorescein angiography (FFA using HRA-2 in 31 normal individuals. The FAZ was studied using both contrast-adjusted and nonadjusted methods. Contrast adjustment was done to obtain better visualization of the finer capillaries around the fovea enabling more precise measurements of the FAZ in normal eyes. Results: The mean area of the FAZ calculated by the contrast-adjusted method was 0.2753 mm 2 (±0.074 and the mean circumference was 2.22 mm (±0.048. By the conventional method, the area and circumference of the FAZ were 0.6241 mm 2 (±0.177 and 3.23 mm (±0.454, respectively. Conclusion: The measurements of area and circumference of FAZ using contrast-adjusted methods were significantly smaller than the conventional method.

  18. Improvement of the Oracle setup and database design at the Heidelberg ion therapy center

    The HIT (Heidelberg Ion Therapy) center is an accelerator facility for cancer therapy using both carbon ions and protons, located at the university hospital in Heidelberg. It provides three therapy treatment rooms: two with fixed beam exit (both in clinical use), and a unique gantry with a rotating beam head, currently under commissioning. The backbone of the proprietary accelerator control system consists of an Oracle database running on a Windows server, storing and delivering data of beam cycles, error logging, measured values, and the device parameters and beam settings for about 100,000 combinations of energy, beam size and particle rate used in treatment plans. Since going operational, we found some performance problems with the current database setup. Thus, we started an analysis that focused on the following topics: hardware resources of the database server, configuration of the Oracle instance, and a review of the database design that underwent several changes since its original design. The analysis revealed issues on all fields. The outdated server will be replaced by a state-of-the-art machine soon. We will present improvements of the Oracle configuration, the optimization of SQL statements, and the performance tuning of database design by adding new indexes which proved directly visible in accelerator operation, while data integrity was improved by additional foreign key constraints. (authors)

  19. Nationwide outbreak of multidrug-resistant Salmonella Heidelberg infections associated with ground turkey: United States, 2011.

    Routh, J A; Pringle, J; Mohr, M; Bidol, S; Arends, K; Adams-Cameron, M; Hancock, W T; Kissler, B; Rickert, R; Folster, J; Tolar, B; Bosch, S; Barton Behravesh, C; Williams, I T; Gieraltowski, L


    On 23 May 2011, CDC identified a multistate cluster of Salmonella Heidelberg infections and two multidrug-resistant (MDR) isolates from ground turkey retail samples with indistinguishable pulsed-field gel electrophoresis patterns. We defined cases as isolation of outbreak strains in persons with illness onset between 27 February 2011 and 10 November 2011. Investigators collected hypothesis-generating questionnaires and shopper-card information. Food samples from homes and retail outlets were collected and cultured. We identified 136 cases of S. Heidelberg infection in 34 states. Shopper-card information, leftover ground turkey from a patient's home containing the outbreak strain and identical antimicrobial resistance profiles of clinical and retail samples pointed to plant A as the source. On 3 August, plant A recalled 36 million pounds of ground turkey. This outbreak increased consumer interest in MDR Salmonella infections acquired through United States-produced poultry and played a vital role in strengthening food safety policies related to Salmonella and raw ground poultry. PMID:25865382

  20. Optical coherence tomography: automatic retina classification through support vector machines

    Bernardes, Rui; Serranho, Pedro; Santos, Torcato; Gonçalves, Valter; Cunha-Vaz, José


    Optical coherence tomography (OCT) is becoming one of the most important imaging modalities in ophthalmology due to its non-invasiveness and by allowing the visualisation the human retina structure in detail. It was recently proposed that OCT data embeds functional information from the human retina. Specifically, it was proposed that blood–retinal barrier status information is present within OCT data from the human retina. Besides this ability, the authors present data supporting the idea ...

  1. Estimation of gastric residence time of the Heidelberg capsule in humans: effect of varying food composition

    In animal and human studies, the gastric emptying of large (greater than 1 mm) indigestible solids is due to the activity of the interdigestive migrating myoelectric complex. The gastric residence time (GRT) of an orally administered, nondigestible, pH-sensitive, radiotelemetric device (Heidelberg capsule) was evaluated in three studies in healthy volunteers. In 6 subjects, the GRT of the Heidelberg capsule was compared with the half-emptying time (t1/2) of diethylenetriaminepentaacetic acid labeled with technetium 99m after a 4-ml/kg liquid fatty meal. The mean (+/-SD) GRT (4.3 +/- 1.4 h) was significantly (p less than 0.001) longer than the mean t1/2 (1.1 +/- 0.3 h); the GRT was prolonged compared with the t1/2 in each subject. In a randomized, crossover trial in 10 subjects, frequent feeding caused a dramatic prolongation in mean GRT of the capsule compared with the fasting state (greater than 14.5 vs. 0.5 h, p less than 0.005). In another crossover study in 6 subjects, the GRT of the capsule was evaluated after an overnight fast, a standard breakfast including solid food, and a liquid meal (i.e., 200 ml of diluted light cream). The mean GRT was 2.6 +/- 0.9 h after the liquid meal vs. 1.2 +/- 0.8 h after fasting (p less than 0.025). The mean GRT after the breakfast was 4.8 +/- 1.5 h, which was significantly greater than that after fasting (p less than 0.001) and after the liquid meal (p less than 0.01). These data suggest that the GRT of the Heidelberg capsule is a marker of the interdigestive migrating myoelectric complex in humans, the interdigestive migrating myoelectric complex can be markedly delayed by frequent feedings with solids, and the interdigestive migrating myoelectric complex is delayed by both liquid and solid meals

  2. Video 11 - Instrucciones Técnicas para el Manejo de un Microscopio Electroquímico de Barrido (SECM): Realización de la Medida - Preparación con Voltamperometría Cíclica (CV)

    Gómez Villarejo, Roberto; Cubillana Aguilera, Laura; Palacios Santander, José María


    Video 10 de 14. Instrucciones Técnicas para el Manejo de un Microscopio Electroquímico de Barrido (SECM). En este video se describe la preparación del sistema para llevar a cabo la medida final. Por consiguiente, se explica cómo llevar a cabo una Voltamperometría Cíclica, a partir de cuya forma/aspecto, se podrá tener una idea sobre el comportamiento del sistema: si está listo para el mapeo final o si, por el contrario, no hay una buena señal eléctrica entre los dispositivos que componen el s...

  3. Aplicación del análisis por calorimetría diferencial de barrido (DSC) para la caracterización de las modificaciones del almidón



    La calorimetría diferencial de barrido (DSC, por sus siglas en ingles) es un análisis térmico que ha permitido identificar en un sistema compuesto de almidón y agua las transiciones y modificaciones de la estructura del gránulo de almidón, verificar la asociación de fragmentos de amilosa y amilopectina (retrogradación) e identificar los cambios en sus características térmicas como consecuencia de tratamientos combinados de calor y humedad. Esta revisión presenta conceptos sobre...

  4. Modeling laser damage to the retina

    Clark, Clifton D.

    This dissertation presents recent progress in several areas related to modeling laser damage to the retina. In Chapter 3, we consider the consequences of using the Arrhenius damage model to predict the damage thresholds of multiple pulse, or repetitive pulse, exposures. We have identified a few fundamental trends associated with the multiple pulse damage predictions made by the Arrhenius model. These trends differ from what would be expected by non-thermal mechanisms, and could prove useful in differentiating thermal and non-thermal damage. Chapter 4 presents a new rate equation damage model hypothesized to describe photochemical damage. The model adds a temperature dependent term to the simple rate equation implied by the principle of reciprocity that is characteristic of photochemical damage thresholds. A recent damage threshold study, conducted in-vitro, has revealed a very sharp transition between thermal and photochemical damage threshold trends. For the wavelength used in the experiment (413 nm), thermal damage thresholds were observed at exposure levels that were twice the expected photochemical damage threshold, based on the traditional understanding of photochemical damage. Our model accounts for this observed trend by introducing a temperature dependent quenching, or repair, rate to the photochemical damage rate. For long exposures that give a very small temperature rise, the model reduces to the principle of reciprocity. Near the transition region between thermal and photochemical damage, the model allows the damage threshold to be set by thermal mechanisms, even at exposure above the reciprocity exposure. In Chapter 5, we describe a retina damage model that includes thermal lensing in the eye by coupling beam propagation and heat transfer models together. Thermal lensing has recently been suggested as a contributing factor to the large increase in measured retinal damage thresholds in the near infrared. The transmission of the vitreous decreases

  5. Artificial Retina Project: Electromagnetic and Thermal Effects

    Lazzi, Gianluca


    This award supported the investigation on electromagnetic and thermal effects associated with the artificial retina, designed in collaboration with national laboratories, universities, and private companies. Our work over the two years of support under this award has focused mainly on 1) Design of new telemetry coils for optimal power and data transfer between the implant and the external device while achieving a significant size reduction with respect to currently used coils; 2) feasibility study of the virtual electrode configuration 3) study the effect of pulse shape and duration on the stimulation efficacy.

  6. Nuclear structure and reactions studied with the Darmstadt-Heidelberg crystal ball

    Metag, V.; Fischer, R.D.; Koch, G.; Kuehn, W.; Muehlhans, R.; Novotny, R.; Ruckelshausen, A.; Stroeher, H.; Habs, D.; Hennrich, H.J.


    Angular momentum distribution in compound nuclei have been derived from ..gamma..-ray multiplicities and angular distributions measured with the Darmstadt-Heidelberg crystall ball. The influence of dynamic barrier fluctuation on the amount of angular momentum absorbed in the fusion process is discussed. Entrance channel effects have been observed which result in different decay paths for compound nuclei at the same excitation energy and spin in different target-projectile combinations. The ..gamma..-decay of resonances in the /sup 12/C + /sup 12/C system has been investigated. The measured ..gamma..-ray yields are consistently smaller than expected for collectively enhanced E2 transitions in a deformed and rigidly rotating intermediate system. The order of magnitude of the experimentally observed ..gamma..-intensity is, however, reproduced in theoretical calculations of nuclear bremsstrahlung, using realistic wave functions of the scattering states. 29 references, 10 figures.

  7. Consortium NCS/GNS: Disposal of spent nuclear fuel from the DKFZ (Heidelberg, Germany)

    Before the decommissioning of the TRIGA HD II reactor of the 'Deutsches Krebsforschungszentrum' in Heidelberg (DKFZ) the spent nuclear fuel (126 TRIGA- F/A) had to be discharged from the reactor and shipped in 2001 to the United States. The Consortium NCS/GNS together with the DKFZ carried out this task including the following essential details: Implementation of structural measures inside the reactor building. Development and fabrication of loading units for the FIA. Development and fabrication of a transfer system for the loading units. Obtaining new German and US certifications for the casks. Loading of the casks. Shipment of the casks from DKFZ to the United States by road and sea. The successful completion of this task once again proved the operational experience of the Consortium NCS/GNS which will be useful for further worldwide shipments of spent nuclear fuel from research reactors. e.g. shipments from Europe, South America and Australia to the United States and France. (author)

  8. Dipolar and quadrupolar detection using an FT-ICR MS setup at the MPIK Heidelberg

    Heck, Michael, E-mail:; Blaum, Klaus; Cakirli, R. Burcu [Max-Planck-Insitute for Nuclear Physics (Germany); Rodriguez, Daniel [Universidad de Granada (Spain); Schweikhard, Lutz [Ernst-Moritz-Arndt University Greifswald, Institute of Physics (Germany); Stahl, Stefan [Stahl-Electronics (Germany); Ubieto-Diaz, Marta [Max-Planck-Insitute for Nuclear Physics (Germany)


    Dipolar and single-phase two-electrode quadrupolar detection schemes have been investigated at a Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) setup built for the KATRIN experiment at the Max-Planck-Institute for Nuclear Physics (MPIK) in Heidelberg. We present first experimental results of {sup 7}Li{sup + } signals from a cylindrical Penning trap configuration for both detection schemes. While the prominent signal of the conventional dipolar detection scheme marks the reduced cyclotron frequency, the main signal for the quadrupolar detection appears at the sum of the reduced cyclotron frequency and the magnetron frequency. For ideal trapping fields, this sum frequency equals the ion cyclotron frequency {nu}{sub c} = qB/(2{pi}m). Sidebands due to the combined motions of the cyclotron mode and magnetron mode are observed by quadrupolar detection which allows the determination of the respective combinations of eigenfrequencies.

  9. Commissioning of the Cryogenic Plant for the Cryogenic Storage Ring (CSR) at Heidelberg

    von Hahn, R; Grieser, M; Haberstroh, C; Kaiser, D; Lange, M; Laux, F; Menk, S; Orlov, D A; Repnow, R; Sieber, T; Quack, H; Varju, J; Wolf A


    At the Max-Planck-Institute for Nuclear Physics in Heidelberg a next generation electrostatic storage ring for low velocity atomic and molecular ion beams is under construction. In contrast to existing electrostatic storage rings, the Cryogenic Storage Ring CSR will be cooled down to temperatures below 2 K. Thus acting as a large cryopump it will provide long storage times and, in addition, open a new field of quantum state controlled molecular physics due to a low heat radiation background from space-like environment. A concept for cooling the storage ring has been developed and is presently tested by means of a linear trap as a prototype with a length of 1/10 of the planned ring. A commercial refrigerator with 21 W at 2 K has been successfully commissioned and was connected to the prototype. This paper presents the status of the cryogenic plant after the commissioning and one year of operation.

  10. The Heidelberg High Current Injector A Versatile Injector for Storage Ring Experiments

    Von Hahn, R; Repnow, R; Schwalm, D; Welsch, C P


    The High Current Injector (HCI) was designed and built as a dedicated injector for the Test Storage Ring in Heidelberg to deliver mainly singly charged Li- and Be-ions. After start for routine operation in 1999 the HCI delivered stable beams during the following years for about 50 % of the experiments with very high reliability. Due to the requirements from the experiment the HCI changed during that period from a machine for singly charged positive ions to an injector for a large variety of molecules as well as positively or negatively charged light ions. After successful commissioning of the custom built 18 GHz high power ECR-source at its present test location various modifications and additions were made in preparation of a possible conversion into an injector for highly charged heavy ions as a second phase. This paper gives an overview of the experience gained in the passed 5 years and presents the status of the upgrade of the HCI.

  11. International outbreak investigation of Salmonella Heidelberg associated with in-flight catering.

    Rebolledo, J


    SUMMARY Rapid and wide dispersal of passengers after flights makes investigation of flight-related outbreaks challenging. An outbreak of Salmonella Heidelberg was identified in a group of Irish travellers returning from Tanzania. Additional international cases sharing the same flight were identified. Our aim was to determine the source and potential vehicles of infection. Case-finding utilized information exchange using experts\\' communication networks and national surveillance systems. Demographic, clinical and food history information was collected. Twenty-five additional cases were identified from Ireland, The Netherlands, Norway, USA and Canada. We conducted a case-control study which indicated a significant association between illness and consumption of milk tart (OR 10·2) and an egg dish (OR 6) served on-board the flight. No food consumed before the flight was associated with illness. Cases from countries other than Ireland provided supplementary information that facilitated the identification of likely vehicles of infection. Timely, committed international collaboration is vital in such investigations.

  12. The Heidelberg-Moscow double beta decay experiment with enriched sup 76 Ge. First result

    Balysh, A.; Belyaev, S.T.; Demehin, A.; Gurov, A.; Kondratenko, I.; Lebedev, V.I. (Max-Planck-Inst. fuer Kernphysik, Heidelberg (Germany)); Beck, M.; Bockholt, J.; Echternach, J.; Heusser, G.; Hirsch, M.; Klapdor-Kleingrothaus, H.V.; Maier, B.; Petry, F.; Piepke, A.; Schmidt-Rohr, U.; Strecker, H.; Zuber, K. (Kurchatov Inst., Moscow (USSR)); Mueller, A. (Ist. Nazionale di Fisica Nucleare, Assergi (Italy))


    The status of the Heidelberg-Moscow {beta}{beta}-experiment using isotopically enriched {sup 76}Ge is reported. The results of 14.8 mol yr (or 1.29 kg yr) of operation are presented. From these data a new half life time for the {beta}{beta}0{nu}-decay of {sup 76}Ge to the ground state of {sup 76}Se of T{sub 1/2}>1.4(2.5)x10{sup 24} yr with 90% (68%) CL can be deduced. For a possible neutrinoless decay to the first excited state a half life of 4.3(8.2)x10{sup 23} yr can be excluded with 90% (68%) CL. (orig.).

  13. Cortical reorganization in recent-onset tinnitus patients by the Heidelberg Model of Music Therapy

    Christoph Maria Krick


    Full Text Available Pathophysiology and treatment of tinnitus still are fields of intensive research. The neuroscientifically motivated Heidelberg Model of Music Therapy, previously developed by the German Center for Music Therapy Research, Heidelberg, Germany, was applied to explore its effects on individual distress and on brain structures. This therapy is a compact and fast application of nine consecutive 50-minutes sessions of individualized therapy implemented over one week. Clinical improvement and long-term effects over several years have previously been published. However the underlying neural basis of the therapy’s success has not yet been explored. In the current study, the therapy was applied to acute tinnitus patients (TG and healthy active controls (AC. Non-treated patients were also included as passive controls (PTC. As predicted, the therapeutic intervention led to a significant decrease of tinnitus-related distress in TG compared to PTC. Before and after the study week, high-resolution MRT scans were obtained for each subject. Assessment by repeated measures design for several groups (two-way ANOVA revealed structural gray matter (GM increase in TG compared to PTC, comprising clusters in precuneus, medial superior frontal areas, and in the auditory cortex. This pattern was further applied as mask for general GM changes as induced by the therapy week. The therapy-like procedure in AC also elicited similar GM increases in precuneus and frontal regions. Comparison between structural effects in TG versus AC was calculated within the mask for general GM changes to obtain specific effects in tinnitus patients, yielding GM increase in right Heschl's gyrus, right Rolandic operculum, and medial superior frontal regions. In line with recent findings on the crucial role of the auditory cortex in maintaining tinnitus-related distress, a causative relation between the therapy-related GM alterations in auditory areas and the long-lasting therapy effects can be

  14. Kompetenzorientierte Evaluation des adaptiven Schulungskonzepts TUBLIK der Universitätsbibliothek Heidelberg

    Benno Homann


    Full Text Available Im Vergleich zu den Bibliotheken angloamerikanischer Länder verwenden deutsche Bibliotheken bisher kaum sozialwissenschaftliche Evaluationsmethoden, um den Nutzen von Veranstaltungskonzepten für die Steigerung von Informationskompetenz nachzuweisen und die Vermittlungsmethoden zu verbessern. Ansatzpunkte zur Beseitigung dieser Defizite bietet das an der Universitätsbibliothek Heidelberg durchgeführte Projekt TUBLIK (Tutoren- und Blended-Learning-basierte Vermittlung von Informationskompetenz, bei dem mehrere sozialwissenschaftliche Verfahren eingesetzt wurden. Mit den angewandten Methoden konnten eine Steigerung der Informationskompetenz bei Studierenden durch TUBLIK nachgewiesen und Vorschläge zur methodischen Optimierung des Konzepts erarbeitet werden. Deutlich wurde auch, dass eine systematische Weiterentwicklung von Evaluationsmethoden zur Messung von Informationskompetenz und der Aufbau von sozialwissenschaftlichen Methodenkompetenzen an Bibliotheken erforderlich sind. Compared to libraries in Anglo-American countries, sociological evaluation methods are only rarely used by German libraries in order to measure the impact of training concepts on information literacy and to improve the teaching methods. The project TUBLIK (Tutoren- und Blended-Learning-basierte Vermittlung von Informationskompetenz at the University Library of Heidelberg, which makes use of several social science methods, offers a starting point for addressing these deficiencies. With the methods applied, it was shown that students’ information literacy competencies have increased due to TUBLIK and it was possible to develop methodological proposals for optimizing the concept. It also became evident that it is necessary to systematically develop evaluation methods for measuring information literacy and to build up expertise in social science methods at libraries.

  15. Upgrade of the server architecture for the accelerator control system at the Heidelberg ion therapy center

    The Heidelberg Ion Therapy Center (HIT) is a heavy ion accelerator facility located at the Heidelberg university hospital and intended for cancer treatment with heavy ions and protons. It provides three treatment rooms for therapy of which two using horizontal beam nozzles are in clinical use and the unique gantry with a 360 degrees rotating beam port is currently under commissioning. The proprietary accelerator control system runs on several classical server machines, including a main control server, a database server running Oracle, a device settings modeling server (DSM) and several gateway servers for auxiliary system control. As the load on some of the main systems, especially the database and DSM servers, has become very high in terms of CPU and I/O load, a change to a more up-to-date blade server enclosure with four redundant blades and a 10 Gbit internal network architecture has been decided. Due to budgetary reasons, this enclosure will at first only replace the main control, database and DSM servers and consolidate some of the services now running on auxiliary servers. The internal adaptable network will improve the communication between servers and database. As all blades in the enclosure are configured identically, one dedicated spare blade is used to provide redundancy in case of hardware failure. Additionally we plan to use simulation software to further improve redundancy and consolidate the services running on gateways and to make dynamic load balancing available to account for different performance needs e.g. in commissioning or therapy use of the accelerator. (authors)

  16. Complete Genome Sequences of Salmonella enterica Serovar Heidelberg Strains Associated with a Multistate Food-Borne Illness Investigation

    Evans, Peter S.; Luo, Yan; Muruvanda, Tim; Ayers, Sherry; Hiatt, Brian; Hoffman, Maria; Zhao, Shaohua; Allard, Marc W.; Brown, Eric W.


    Next-generation sequencing is being evaluated for use with food-borne illness investigations, especially when the outbreak strains produce patterns that cannot be discriminated from non-outbreak strains using conventional procedures. Here we report complete genome assemblies of two Salmonella enterica serovar Heidelberg strains with a common pulsed-field gel electrophoresis pattern isolated during an outbreak investigation.

  17. [From stand-alone solution to longitudinal communication curriculum--development and implementation at the Faculty of Medicine in Heidelberg].

    Sator, Marlene; Jünger, Jana


    At the Faculty of Medicine in Heidelberg, implementation of an interdisciplinary longitudinal curriculum was started in 2001 with the goal of achieving sustained promotion of communicative and clinical competences. The aim of this paper is to describe the development and implementation of Heidelberg's longitudinal communication curriculum. Furthermore, innovative aspects and strategies are discussed. The methodological approaches for development and implementation were Kern's "Six-step Approach" and a SWOT analysis. The process resulted in an innovative communication curriculum that starts with an integrated curriculum for developing clinical and communicative competence in the pre-clinical phase and continues in the clinical phase with medical communication and interactive training. Satisfaction with the communication curriculum and its effectiveness were rated highly by students. Residents who had graduated from Faculty of Medicine in Heidelberg rated the extent to which they had communicative competencies at the time of their graduation at their disposal significantly higher than residents who had graduated from the other 4 medical faculties in Baden-Württemberg. The experiences gained in Heidelberg can be applied by other faculties. PMID:25941988

  18. Cell death in the developing vertebrate retina.

    Vecino, Elena; Hernández, María; García, Mónica


    Programmed cell death occurs naturally, as a physiological process, during the embryonic development of multicellular organisms. In the retina, which belongs to the central nervous system, at least two phases of cell death have been reported to occur during development. An early phase takes place concomitant with the processes of neurogenesis, cell migration and cell differentiation. A later phase affecting mainly neurons occurs when connections are established and synapses are formed, resulting in selective elimination of inappropriate connections. This pattern of cell death in the developing retina is common among different vertebrates. However, the timing and magnitude of retinal cell death varies among species. In addition, a precise regulation of apoptosis during retinal development has been described. Factors such as neurotrophins, among many others, and electrical activity influence the survival of retinal cells during the course of development. In this paper, we present a summary of these different aspects of programmed cell death during retinal development, and examine how these differ among different species. PMID:15558487

  19. Topography of ganglion cell production in the cat's retina

    The ganglion cells of the cat's retina form several classes distinguishable in terms of soma size, axon diameter, dendritic morphology, physiological properties, and central connections. Labeling with [3H]thymidine shows that the ganglion cells which survive in the adult are produced as several temporally shifted, overlapping waves: medium-sized cells are produced before large cells, whereas the smallest ganglion cells are produced throughout the period of ganglion cell generation. Large cells and medium-sized cells show the same distinctive pattern of production, forming rough spirals around the area centralis. The oldest cells tend to lie superior and nasal to the area centralis, whereas cells in the inferior nasal retina and inferior temporal retina are, in general, progressively younger. Within each retinal quadrant, cells nearer the area centralis tend to be older than cells in the periphery, but there is substantial overlap. The retinal raphe divides the superior temporal quadrant into two zones with different patterns of cell addition. Superior temporal retina near the vertical meridian adds cells only slightly later than superior nasal retina, whereas superior temporal retina near the horizontal meridian adds cells very late, contemporaneously with inferior temporal retina. The broader wave of production of smaller ganglion cells seems to follow this same spiral pattern at its beginning and end. The presence of the area centralis as a nodal point about which ganglion cell production in the retinal quadrants pivots suggests that the area centralis is already an important retinal landmark even at the earliest stages of retinal development

  20. Development of diabetes-induced acidosis in the rat retina.

    Dmitriev, Andrey V; Henderson, Desmond; Linsenmeier, Robert A


    We hypothesized that the retina of diabetic animals would be unusually acidic due to increased glycolytic metabolism. Acidosis in tumors and isolated retina has been shown to lead to increased VEGF. To test the hypothesis we have measured the transretinal distribution of extracellular H(+) concentration (H(+)-profiles) in retinae of control and diabetic dark-adapted intact Long-Evans rats with ion-selective electrodes. Diabetes was induced by intraperitoneal injection of streptozotocin. Intact rat retinae are normally more acidic than blood with a peak of [H(+)]o in the outer nuclear layer (ONL) that averages 30 nM higher than H(+) in the choroid. Profiles in diabetic animals were similar in shape, but diabetic retinae began to be considerably more acidic after 5 weeks of diabetes. In retinae of 1-3 month diabetics the difference between the ONL and choroid was almost twice as great as in controls. At later times, up to 6 months, some diabetics still demonstrated abnormally high levels of [H(+)]o, but others were even less acidic than controls, so that the average level of acidosis was not different. Greater variability in H(+)-profiles (both between animals and between profiles recorded in one animal) distinguished the diabetic retinae from controls. Within animals, this variability was not random, but exhibited regions of higher and lower H(+). We conclude that retinal acidosis begins to develop at an early stage of diabetes (1-3 months) in rats. However, it does not progress, and the acidity of diabetic rat retina was diminished at later stages (3-6 months). Also the diabetes-induced acidosis has a strongly expressed local character. As result, the diabetic retinas show much wider variability in [H(+)] distribution than controls. pH influences metabolic and neural processes, and these results suggest that local acidosis could play a role in the pathogenesis of diabetic retinopathy. PMID:27262608

  1. A High Resolution Spectrograph for the 72 cm Waltz Telescope at Landessternwarte, Heidelberg

    Tala, M; Grill, M; Harris, R J; Stürmer, J; Schwab, C; Gutcke, T; Reffert, S; Quirrenbach, A; Seifert, W; Mandel, H; Geuer, L; Schäffner, L; Thimm, G; Seemann, U; Tietz, J; Wagner, K


    The Waltz Spectrograph is a fiber-fed high-resolution \\'echelle spectrograph for the 72 cm Waltz Telescope at the Landessternwarte, Heidelberg. It uses a 31.6 lines/mm 63.5$^{\\circ}$ blaze angle \\'echelle grating in white-pupil configuration, providing a spectral resolving power of $R\\sim$65,000 covering the spectral range between 450$-$800\\,nm in one CCD exposure. A prism is used for cross-dispersion of \\'echelle orders. The spectrum is focused by a commercial apochromat onto a 2k$\\times$2k CCD detector with 13.5$\\mu$m per pixel. An exposure meter will be used to obtain precise photon-weighted midpoints of observations, which will be used in the computation of the barycentric corrections of measured radial velocities. A stabilized, newly designed iodine cell is employed for measuring radial velocities with high precision. Our goal is to reach a radial velocity precision of better than 5 m/s, providing an instrument with sufficient precision and sensitivity for the discovery of giant exoplanets. Here we descr...

  2. International outbreak investigation of Salmonella Heidelberg associated with in-flight catering.

    Rebolledo, J; Garvey, P; Ryan, A; O'Donnell, J; Cormican, M; Jackson, S; Cloak, F; Cullen, L; Swaan, C M; Schimmer, B; Appels, R W; Nygard, K; Finley, R; Sreenivasan, N; Lenglet, A; Gossner, C; McKeown, P


    Rapid and wide dispersal of passengers after flights makes investigation of flight-related outbreaks challenging. An outbreak of Salmonella Heidelberg was identified in a group of Irish travellers returning from Tanzania. Additional international cases sharing the same flight were identified. Our aim was to determine the source and potential vehicles of infection. Case-finding utilized information exchange using experts' communication networks and national surveillance systems. Demographic, clinical and food history information was collected. Twenty-five additional cases were identified from Ireland, The Netherlands, Norway, USA and Canada. We conducted a case-control study which indicated a significant association between illness and consumption of milk tart (OR 10.2) and an egg dish (OR 6) served on-board the flight. No food consumed before the flight was associated with illness. Cases from countries other than Ireland provided supplementary information that facilitated the identification of likely vehicles of infection. Timely, committed international collaboration is vital in such investigations. PMID:23890227

  3. The intensity feedback system at Heidelberg Ion-Beam Therapy Centre

    Schoemers, Christian, E-mail:; Feldmeier, Eike; Naumann, Jakob; Panse, Ralf; Peters, Andreas; Haberer, Thomas


    At Heidelberg Ion-Beam Therapy Centre (HIT), more than 2500 tumour patients have been treated with charged particle beams since 2009 using the raster scanning method. The tumour is irradiated slice-by-slice, each slice corresponding to a different beam energy. For the particle dose of each raster point the pre-irradiation by more distal slices has to be considered. This leads to highly inhomogeneous dose distributions within one iso-energy slice. The particles are extracted from the synchrotron via transverse RF knock-out. A pure feed forward control cannot take into account fluence inhomogeneities or deal with intensity fluctuations. So far, fluctuations have been counteracted by a reduced scanning velocity. We now added a feedback loop to the extraction system. The dose monitoring ionisation chambers in front of the patient have been coupled to the extraction device in the synchrotron. Characterization and implementation of the intensity feedback system into the HIT facility is described here. By its implementation the treatment time has been reduced by 10% in average.

  4. The first commandment in the Heidelberg Catechism: Theological insights of Philipp Melanchthon and Zacharias Ursinus

    Ignatius W.C. van Wyk


    Full Text Available This article focuses on the exposition of the first commandment in the Heidelberg Catechism (HC. Reconstructions of the original German and Latin texts are presented. Zacharias Ursinus, the primary author of the HC, was a student of Philipp Melanchthon in Wittenberg. Two important publications of Melanchthon have been revisited in search of the theological background and context behind the HC. Ursinus’ expositions of the first commandment in his Small and Large Catechisms, as well as some of the insights into his dogmatic lectures are explained in an effort to create a better understanding of the exposition of the HC.Die artikel fokus op die uitleg van die eerste gebod in die Heidelbergse Kategismus (HK. Rekonstruksies van die oorspronklike Duitse en Latynse tekste word voorgelê. Zacharias Ursinus, die primêre outeur van die HK, was ’n leerling van Philipp Melanchthon in Wittenberg. Twee belangrike publikasies van Melanchthon is nagevors in die soeke na die teologiese denkwêreld as agtergrond tot die HK. Ursinus se uitleg van die eerste gebod in sy Klein en Groot Kategismusse, asook sommige van die insigte wat in sy die dogmatieklesings vervat is, word verduidelik in ’n poging om ’n beter begrip van die uitleg van die HK teweeg te bring.

  5. Development of Recombinant Flagellar Antigens for Serological Detection of Salmonella enterica Serotypes Enteritidis, Hadar, Heidelberg, and Typhimurium in Poultry

    Hofacre, Charles L.; Peter S. Holt; Lee, Margie D.; Susan Sanchez; Joseph Minicozzi; Maurer, John J.


    Accurate and fast detection of harmful Salmonella is a major concern of food safety. Common Salmonella serotypes responsible for human associated foodborne outbreaks are S. Enteritidis, S. Hadar, S. Heidelberg, and S. Typhimurium are also commonly isolated from poultry. Serology is commonly used to monitor disease in poultry, therefore application of Salmonella serotype-specific test will have added value in Salmonella surveillance or monitoring vaccine efficacy. Recombinant flagellins were p...

  6. Intake of heterocyclic aromatic amines from meat in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Heidelberg cohort.

    Rohrmann, Sabine; Zoller, Dorothee; Hermann, Silke; Linseisen, Jakob


    It was the aim of the present study to estimate the intake of heterocyclic aromatic amines (HCA) from meat, which have been associated with cancer risk in several epidemiological studies, of 21 462 subjects who participated in the European Prospective Investigation into Cancer and Nutrition (EPIC) in Heidelberg. This was accomplished by using a detailed dietary questionnaire that assessed meat consumption, cooking methods, and degree of browning of the respective food items. Median total HCA ...

  7. Heidelberger Poetikdozentur 2014 - Wilhelm Genazino: Furcht und Zittern der Überempfindlichen – Die Angst vor der Penetranz des Wirklichen

    Genazino, Wilhelm


    Der Schriftsteller Wilhelm Genazino übernahm zwischen dem 23. Mai und 10. Juni 2014 die Poetikdozentur an der Universität Heidelberg. Im Mittelpunkt des vom Germanistischen Seminar organisierten Veranstaltungsprogramms standen drei öffentliche Poetikvorträge, in denen sich Genazino mit seinem literarischen Schreiben auseinandersetzte. "Furcht und Zittern der Überempfindlichen – Die Angst vor der Penetranz des Wirklichen" war der erste der drei Vorträge, die der Schriftsteller im Rahmen der Po...

  8. Determination of two dimensional trace gas distributions using tomographic LP-DOAS measurements in the city of Heidelberg, Germany

    Pöhler, Denis


    Tomographic Long path Differential Optical Absorption Spectroscopy (LP-DOAS) allows two and three dimensional determination of trace gas distributions by measuring the average concentration along 10 to 20 intersecting light paths and applying tomographic inversion techniques. In this thesis such a setup was developed and applied for the first time to determine the horizontal distribution of several trace gases in the open atmosphere. The measurements took place in the city of Heidelberg, Germ...

  9. Intravitreal Injection of AAV2 Transduces Macaque Inner Retina

    Yin, Lu; Greenberg, Kenneth; Hunter, Jennifer J.; Dalkara, Deniz; Kolstad, Kathleen D; Masella, Benjamin D.; Wolfe, Robert; Visel, Meike; Stone, Daniel; Libby, Richard T.; DiLoreto, David; Schaffer, David; Flannery, John; Williams, David R.; Merigan, William H.


    Intravitreally injected AAV2 transduced inner retinal cells in a restricted region at the macaque fovea. Because macaque and human eyes are similar, the results suggest a need to improve transduction methods in gene therapy for the human inner retina.

  10. Genetics Home Reference: gyrate atrophy of the choroid and retina

    ... the choroid. During childhood, they begin experiencing nearsightedness ( myopia ), difficulty seeing in low light (night blindness), and ... the choroid and retina in a child with myopia. Indian Pediatr. 2001 Aug;38(8):914-8. ...

  11. Kriegszeitungen der Universitätsbibliothek Heidelberg: Überlegungen zu Erschließung, Erhaltung und Präsentation des Bestandes

    Daucher, Elke


    In der Universitätsbibliothek Heidelberg befinden sich zahlreiche Kriegszeitungen aus dem 1. und 2. Weltkrieg. In dieser Arbeit werden zunächst die verschiedenen Kriegszeitungstypen vorgestellt. Da der Bestand an Feld-, bzw. Frontzeitungen am umfangreichsten ist, wird auf deren Entstehungshintergrund näher eingegangen. Anschließend werden die Kriegszeitungstitel durch ein Schema erschlossen, und der Bestand der UB Heidelberg mit anderen Institutionen verglichen. Da sich die Kriegszeitungen in...

  12. Genome Sequences of Salmonella enterica Serovar Heidelberg Isolates Isolated in the United States from a Multistate Outbreak of Human Salmonella Infections

    Hoffmann, Maria; Luo, Yan; Lafon, Patricia C.; Timme, Ruth; Allard, Marc W.; McDermott, Patrick F.; Brown, Eric W.; Zhao, Shaohua


    Salmonella enterica is recognized as one of the most common bacterial agents of foodborne illness. We report draft genomes of four Salmonella serovar Heidelberg isolates associated with the recent multistate outbreak of human Salmonella Heidelberg infections linked to kosher broiled chicken livers in the United States in 2011. Isolates 2011K-1259 and 2011K-1232 were recovered from humans, whereas 2011K-1724 and 2011K-1726 were isolated from chicken liver. Whole genome sequence analysis of the...

  13. Cementos Belíticos: caracterización de los productos de hidratación por microscopía electronica de barrido y microanálisis de rayos x

    Goñi Elizalde, Sara; Guerrero Bustos, Ana; Lorenzo García, Mª Paz


    En este trabajo se presenta la caracterización microscópica de dos tipos de cementos belíticos de cenizas volantes (CBCV) y sus productos de hidratación, por medio de microscopía electrónica de barrido, microanálisis cuantitativo por energía dispersa de rayos X y difracción de rayos X. Los cementos se sintetizaron a partir de cenizas volantes de la combustión de carbón, de alto contenido en cal, empleando una ruta de síntesis de baja energía basada en la obtención de fases precursoras del cem...

  14. Aplicación del análisis por calorimetría diferencial de barrido (DSC para la caracterización de las modificaciones del almidón



    Full Text Available La calorimetría diferencial de barrido (DSC, por sus siglas en ingles es un análisis térmico que ha permitido identificar en un sistema compuesto de almidón y agua las transiciones y modificaciones de la estructura del gránulo de almidón, verificar la asociación de fragmentos de amilosa y amilopectina (retrogradación e identificar los cambios en sus características térmicas como consecuencia de tratamientos combinados de calor y humedad. Esta revisión presenta conceptos sobre el DSC, la estructura y las transiciones de fase del gránulo de almidón. Adicionalmente, se recopilan investigaciones donde se utilizó esta técnica para la caracterización de distintos almidones.

  15. Light-evoked S-nitrosylation in the retina.

    Tooker, Ryan E; Vigh, Jozsef


    Nitric oxide (NO) synthesis in the retina is triggered by light stimulation. NO has been shown to modulate visual signal processing at multiple sites in the vertebrate retina, via activation of the most sensitive target of NO signaling, soluble guanylate cyclase. NO can also alter protein structure and function and exert biological effects directly by binding to free thiol groups of cysteine residues in a chemical reaction called S-nitrosylation. However, in the central nervous system, including the retina, this reaction has not been considered to be significant under physiological conditions. Here we provide immunohistochemical evidence for extensive S-nitrosylation that takes place in the goldfish and mouse retinas under physiologically relevant light intensities, in an intensity-dependent manner, with a strikingly similar pattern in both species. Pretreatment with N-ethylmaleimide (NEM), which occludes S-nitrosylation, or with 1-(2-trifluromethylphenyl)imidazole (TRIM), an inhibitor of neuronal NO synthase, eliminated the light-evoked increase in S-nitrosylated protein immunofluorescence (SNI) in the retinas of both species. Similarly, light did not increase SNI, above basal levels, in retinas of transgenic mice lacking neuronal NO synthase. Qualitative analysis of the light-adapted mouse retina with mass spectrometry revealed more than 300 proteins that were S-nitrosylated upon illumination, many of which are known to participate directly in retinal signal processing. Our data strongly suggest that in the retina light-evoked NO production leads to extensive S-nitrosylation and that this process is a significant posttranslational modification affecting a wide range of proteins under physiological conditions. PMID:25823749

  16. Effect of accelerated iron ions on the retina

    The eyes of rats were exposed to doses of 0.1 and 2.5 Gy of 450-MeV/amu 56Fe particles (LET approximately 195 keV/microns). The beam axes were oriented perpendicular to the central retina of the animals. Retinas were harvested immediately (less than 10 min), 24 h, 15 days, 136 days, and 186 days after the experiment. The retinas of animals of equivalent ages were sampled at the same intervals. By Day 15, the spatial densities of the pigment epithelial, photoreceptor, and bipolar cells in retinas irradiated with 2.5 Gy were 15 to 20% lower than those of the controls. The cellular density of the pigment epithelium returned to the control level by Day 186 while photoreceptor and bipolar cell numbers remained depressed. One and fifteen days after irradiation, the choroidal vessels showed signs of radiation damage. Exposure to 0.1 Gy did not affect the cellular density within the retina at the interval examined (186 days). None of the retinas showed evidence of track-specific injury that could be interpreted as microlesions or tunnel lesions

  17. Heidelberg-Moscow ββ experiment with 76Ge: Full setup with five detectors

    The full setup of the Heidelberg-Moscow double β decay experiment is presented. This experiment gives at present the most stringent upper bound, improving the neutrino mass limit into the sub-eV range. Out of 19.2 kg of 86% enriched 76Ge five crystals were grown with a total mass of 11.51 kg. Since February 1995 all five detectors, corresponding to 10.96 kg active mass, are in regular operation in the Gran Sasso underground laboratory, four of them in a common shield. No signal is observed for the neutrinoless double β decay (0νββ). The measured data from the first three enriched detectors with a statistical significance of 13.60 kgyr result in a new half-life limit of T1/2(0+→0+)>7.4x1024 yr (90% C.L.). With this limit a Majorana mass of the neutrinos larger than 0.6 eV (90% C.L.) is excluded. From the data taken in the previously operated setup with three enriched detectors in a common shielding and a statistical significance of 10.58 kgyr new results are extracted for the two neutrino double β decay (2νββ) of 76Ge. The procedure of a quantitative and model-independent description of the background via a Monte Carlo simulation is outlined in some detail. The combined result is T1/22ν=[1.77-0.01+0.01(stat)-0.11+0.13(sys)]x1021 yr. Further on the results concerning new Majoron models and the impact on SUSY parameters are briefly reviewed. Future improvements on the background with the application of digital pulse shape analysis are discussed and an outlook on the future of ββ research is given. copyright 1996 The American Physical Society

  18. Fluorescein angiography of the canine retina

    The retinal vascular bed was examined in 37 canine eyes by studying 50 retinal fluorangiograms. All angiographic phases could distinctly be visualized by the use of a small intravenous bolus of 10 mg/kg fluorescein. The choroidal phase is characterized by spot-like and lobular filling of the choriocapillaris. By coalescence of the choroidal lobules, this uneven filling progressively disappears in the subsequent phases. The retinal arterial phase is characterized by a hyperfluorescence of the retinal arterioles at the level of the optic disc border. The time interval between the start of the choroidal phase and the retinal arterial phase is very short due to the common origin of the choroidal and retinal arteries from the choroidoretinal arteries. The retinal arterio-venous phase is characterized by a complete filling of the smaller arterioles, capillaries, and venules. During this phase the branching pattern of the retinal blood vessels at the area centralis region can be most easily studied. This also applies to the periarteriolar capillary-free zones and the radial peripapillary capillaries. The retinal early venous phase is characterized by the onset of laminar flow in the larger retinal venules. A homogeneous and complete filling of the larger venules is characteristic for the onset of the late venous phase. During the retinal venous phase the border venule can be observed just posterior to the ora ciliaris retinae. Fluorescein angiography of the canine retinal microvasculature shows that the dog is less suitable as an experimental animal model in ophthalmology, due to the presence of the choroidal tapetum which reflects fluorescent light and thus diminishes the contrast between the retinal blood vessels and the background

  19. A biphasic pattern of gene expression during mouse retina development

    Soares Marcelo


    Full Text Available Abstract Background Between embryonic day 12 and postnatal day 21, six major neuronal and one glia cell type are generated from multipotential progenitors in a characteristic sequence during mouse retina development. We investigated expression patterns of retina transcripts during the major embryonic and postnatal developmental stages to provide a systematic view of normal mouse retina development, Results A tissue-specific cDNA microarray was generated using a set of sequence non-redundant EST clones collected from mouse retina. Eleven stages of mouse retina, from embryonic day 12.5 (El2.5 to postnatal day 21 (PN21, were collected for RNA isolation. Non-amplified RNAs were labeled for microarray experiments and three sets of data were analyzed for significance, hierarchical relationships, and functional clustering. Six individual gene expression clusters were identified based on expression patterns of transcripts through retina development. Two developmental phases were clearly divided with postnatal day 5 (PN5 as a separate cluster. Among 4,180 transcripts that changed significantly during development, approximately 2/3 of the genes were expressed at high levels up until PN5 and then declined whereas the other 1/3 of the genes increased expression from PN5 and remained at the higher levels until at least PN21. Less than 1% of the genes observed showed a peak of expression between the two phases. Among the later increased population, only about 40% genes are correlated with rod photoreceptors, indicating that multiple cell types contributed to gene expression in this phase. Within the same functional classes, however, different gene populations were expressed in distinct developmental phases. A correlation coefficient analysis of gene expression during retina development between previous SAGE studies and this study was also carried out. Conclusion This study provides a complementary genome-wide view of common gene dynamics and a broad molecular

  20. Aberrant activity in degenerated retinas revealed by electrical imaging

    Günther eZeck


    Full Text Available In this review I present and discuss the current understanding of aberrant electrical activity found in the ganglion cell layer (GCL of rod-degenerated (rd mouse retinas. The reported electrophysiological properties revealed by electrical imaging using high-density microelectrode arrays can be subdivided between spiking activity originating from retinal ganglion cells (RGCs and local field potentials reflecting strong trans-membrane currents within the GCL. RGCs in rod-degenerated retinas show increased and rhythmic spiking compared to age-matched wild-type retinas. Fundamental spiking frequencies range from 5 to 15 Hz in various mouse models. The rhythmic RGC spiking is driven by a presynaptic network comprising AII amacrine and bipolar cells. In the healthy retina this rhythm-generating circuit is inhibited by photoreceptor input. A unique physiological feature of rd retinas is rhythmic local field potentials (LFP manifested as spatially-restricted low-frequency (5–15 Hz voltage changes. Their spatiotemporal characterization revealed propagation and correlation with RGC spiking. LFPs rely on gap-junctional coupling and are shaped by glycinergic and by GABAergic transmission. The aberrant RGC spiking and LFPs provide a simple readout of the functionality of the remaining retinal circuitry which can be used in the development of improved vision restoration strategies.

  1. Retina neural circuitry seen with particle detector technology

    CERN Bulletin


    Using particle physics techniques, high energy physics researchers have recently provided new insight into neural circuits inside the retina. After uncovering a new type of retinal cell and mapping how the retina deals with colours, the team from Santa Cruz (US), Krakow and Glasgow is now turning its attention to more complex issues such as how the retina gets wired up and how the brain deals with the signals it receives from the retina. All this using technology derived from high-density, multistrip silicon detectors…   Seen from the point of view of a particle physicist, eyes are image detectors that can gather many different types of data: light and dark, different colours, motion, etc. In particular, the retina, a thin tissue that lines the back of the eye, is a biological pixel detector that detects light and converts it to electrical signals that travel through the optic nerve to the brain. Neurobiologists know that many different cell types are involved in these processes, but they...

  2. Selective Gene Transfer to the Retina Using Intravitreal Ultrasound Irradiation

    Shozo Sonoda


    Full Text Available This paper aims to evaluate the efficacy of intravitreal ultrasound (US irradiation for green fluorescent protein (GFP plasmid transfer into the rabbit retina using a miniature US transducer. Intravitreal US irradiation was performed by a slight modification of the transconjunctival sutureless vitrectomy system utilizing a small probe. After vitrectomy, the US probe was inserted through a scleral incision. A mixture of GFP plasmid (50 μL and bubble liposomes (BLs; 50 μL was injected into the vitreous cavity, and US was generated to the retina using a SonoPore 4000. The control group was not exposed to US. After 72 h, the gene-transfer efficiency was quantified by counting the number of GFP-positive cells. The retinas that received plasmid, BL, and US showed a significant increase in the number (average ± SEM of GFP-positive cells (32±4.9; n=7; P<0.01 . No GFP-positive cells were observed in the control eyes (n=7. Intravitreal retinal US irradiation can transfer the GFP plasmid into the retina without causing any apparent damage. This procedure could be used to transfer genes and drugs directly to the retina and therefore has potential therapeutic value.

  3. Microgravity effects on neural retina regeneration in the newt

    Grigoryan, E. N.; Anton, H. J.; Mitashov, V. I.

    Data on forelimb and eye lens regenerationin in urodeles under spaceflight conditions (SFC) have been obtained in our previous studies. Today, evidence is available that SFC stimulate regeneration in experimental animals rather than inhibit it. The results of control on-ground experiments with simulated microgravity suggest that the stimulatory effect of SFC is due largely to weightlessness. An original experimental model is proposed, which is convenient for comprehensively analyzing neural regeneration under SFC. The initial results described here concern regeneration of neural retina in Pleurodeles waltl newts exposed to microgravity simulated in radial clinostat. After clinorotation for seven days (until postoperation day 16), a positive effect of altered gravity on structural restoration of detached neural retina was confirmed by a number of criteria. Specifically, an increased number of Müllerian glial cells, an increased relative volume of the plexiform layers, reduced cell death, advanced redifferentiation of retinal pigment epithelium, and extended areas of neural retina reattachment were detected in experimental newts. Moreover, cell proliferation in the inner nuclear layer of neural retina increased as compared with control. Thus, low gravity appears to intensify natural cytological and molecular mechanisms of neural retina regeneration in lower vertebrates.

  4. Comparative study of optic disc measurement by Copernicus optical coherence tomography and Heidelberg retinal tomography

    YANG Qing-song; YU Ya-jie; LI Shu-ning; LIU Juan; HAO Ying-juan


    Background Copernicus optical coherence tomography (SOCT) is a new,ultra high-speed and high-resolution instrument available for clinical evaluation of optic nerve.The purpose of the study was to compare the agreements between SOCT and Heidelberg retinal tomography (HRT).Methods A total of 44 healthy normal volunteers were recruited in this study.One eye in each subject was selected randomly.Agreement between SOCT and HRT-3 in measuring optic disc area was assessed using Bland-Altman plots.Relationships between measurements of optic nerve head parameter obtained by SOCT and HRT-3 were assessed by Pearson correlation.Results There was no significant difference in the average cup area (0.306 vs.0.355 mm,P=0.766),cup volume (0.158 vs.0.130 mm,P=0.106) and cup/disc ration (0.394 vs.0.349 mm,P=0.576) measured by the two instruments.However,other optic disc parameters from SOCT were significantly lower compared with HRT-3.The Bland-Altman plot revealed good agreement of cup area and cup volume measured by SOCT and HRT-3.Bad agreement of disc area,rim area,rim volume and cup/disc ratio were found between SOCT and HRT-3.The highest correlations between the two instruments were observed for cup area (r2=0.783,P=0.000) and cup/disc ratio (r2=0.669,P=0.000),whereas the lowest correlation was observed for disc area (r2=0.100,P=0.037),rim area (r2=0.275,P=0.000),cup volume (r2=0.005,P=0.391) and rim volume (r2=0.021,P=0.346).Conclusions There were poor agreements between SOCT and HRT-3 for measurement of optic nerve parameters except cup area and cup volume.Measurement results of the two instruments are not interchangeable.

  5. Risks Involved in the Use of Enrofloxacin for Salmonella Enteritidis or Salmonella Heidelberg in Commercial Poultry

    Morales-Barrera, Eduardo; Calhoun, Nicole; Lobato-Tapia, Jose L.; Lucca, Vivian; Prado-Rebolledo, Omar; Hernandez-Velasco, Xochitl; Merino-Guzman, Ruben; Petrone-García, Victor M.; Latorre, Juan D.; Mahaffey, Brittany D.; Teague, Kyle D.; Graham, Lucas E.; Wolfenden, Amanda D.; Baxter, Mikayla F. A.; Hargis, Billy M.; Tellez, Guillermo


    The objectives of the present study were to evaluate the risks involved in the use of Enrofloxacin for Salmonella Enteritidis (SE) or Salmonella Heidelberg (SH) in commercial poultry and determine the effects of a probiotic as an antibiotic alternative. Two experiments were conducted to evaluate the risks involved in the use of Enrofloxacin for SE or SH in commercial poultry. Experiment 1 consisted of two trials. In each trial, chickens were assigned to one of three groups; control + SE challenged; Enrofloxacin 25 mg/kg + SE; and Enrofloxacin 50 mg/kg + SE. Chickens received Enrofloxacin in the drinking water from days 1 to 5 of age. On day 6, all groups received fresh water without any treatment. All chickens were orally gavaged with 107 cfu/chick of SE at 7 days of age and euthanized on 8 days of age. In Experiment 2, turkey poults were assigned to one of the three groups; control + SH; probiotic + SH; and Enrofloxacin 50 mg/kg + SH. Poults received probiotic or Enrofloxacin in the drinking water from days 1 to 5 of age. On day 6, poults received fresh water without any treatment. Poults were orally gavaged with 107 cfu/poult of SH at 7 days of age. Poults were weighed and humanely killed 24 h post-SH challenge to evaluate serum concentration of fluorescein isothiocyanate-dextran to evaluate intestinal permeability, metagenomics, and SH infection. In both trials of Experiment 1, chickens treated with Enrofloxacin were more susceptible to SE organ invasion and intestinal colonization when compared with control non-treated chickens (P < 0.05). In Experiment 2, poults treated with 50 mg/kg of Enrofloxacin showed an increase in body weight, however, this group also showed an increase in SH susceptibility, intestinal permeability, and lower proportion of Firmicutes and Bacteroidetes, but with control group had the highest proportion of Proteobacteria. By contrast, poults that received the probiotic had the highest

  6. State-selective quantum interference observed in the photorecombination of Hg75+...78+ ions at the Heidelberg EBIT

    The well-known Fano-profiles appearing in differential photonionization cross sections when resonances are present can also be observed in the time-reversed process of photorecombination of highly charged ions, where direct and indirect processes leading to the same final quantum state of the ion and the photon field can interfere, thus producing asymmetric lines shapes. Experiments performed at the Heidelberg electron beam ion trap with Hg75+...78+ ions have delivered state-selective Fano parameters and accurate resonance energies

  7. Staff review of 'Radioecological assessment of the Wyhl nuclear power plant': Analysis of the report prepared by the University of Heidelberg, West Germany. Draft summary report

    The Heidelberg Report presents an assessment of the environmental radiological impact of a proposed pressurized-water reactor to be built near Wyhl, West Germany. The assessment is based largely on mathematical models that are used to calculate doses to humans in the area surrounding a reactor site and describe the movement of radioactive materials in the environment. These are the same mathematical models that are used by the U.S. Nuclear Regulatory Commission (NRC) in licensing reactors in the United States. The NRC uses these models to make sure that any radiation exposure due to a reactor is far below national and international recommended 'safe' levels, as well as below natural radiation levels. The NRC staff reviewed certain parts of the Heidelberg Report because the report implied that the NRC may be substantially underestimating doses to individuals living near nuclear power plants by using incorrect values for parameters in the mathematical models. Although the Heidelberg Report assessment is based largely on environmental models described in four NRC Regulatory Guides, the NRC staff's review of the Heidelberg Report indicates that the Heidelberg authors used values for some model parameters that are too high

  8. From reformation to counter-reformation to further reformation: A picture of the anti-Roman background of the Heidelberg Catechism

    Erik van Alten


    Full Text Available The anti-Roman sentiment of the Heidelberg Catechism is well-documented. In its contents the Catechism often seeks to combat Roman doctrine. However, this anti-Roman sentiment did not have its origin from textbooks and it was not merely an academic exercise. It was first and foremost a reaction to the ecclesiastical context of that time. At the same time that Elector Frederick III commissioned the writing of the Heidelberg Catechism, the Council of Trent was meeting on the other side of the Alpine mountains. Remarkably, this meeting had only recently decided to write a catechism of its own. It is very likely that the decision-makers in Heidelberg were aware of what was happening in Trent, and reacted accordingly. Underlying the decision to commission and write the Heidelberg Catechism was the acknowledgment of the importance of catechetical teaching. In several documents, which are closely related to the Heidelberg Catechism, the importance of catechetical teaching is highlighted. Interestingly, however, these documents also contrast the reformed principal of catechetical teaching with the Roman sacrament of confirmation. Whereas catechetical teaching leads children on the way from their baptism to the Lord’s Supper, the sacrament of confirmation takes away the urgency for any form of catechetical teaching.

  9. Retina-like sensor image coordinates transformation and display

    Cao, Fengmei; Cao, Nan; Bai, Tingzhu; Song, Shengyu


    For a new kind of retina-like senor camera, the image acquisition, coordinates transformation and interpolation need to be realized. Both of the coordinates transformation and interpolation are computed in polar coordinate due to the sensor's particular pixels distribution. The image interpolation is based on sub-pixel interpolation and its relative weights are got in polar coordinates. The hardware platform is composed of retina-like senor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes the real-time image acquisition, coordinate transformation and interpolation.

  10. The doctrine on God, as demonstrated and confessed in the Heidelberg Catechism

    Carel F.C. Coetzee


    Full Text Available Although the Heidelberg Catechism (HC does not deal with a systematic doctrine on God and although there are not many sources available on the specific subject, it is a most important subject when dealing with the theology of the HC (W. van ’t Spijker. Due to the prescribed length of the article, it only focuses on two aspects of the doctrine on God, namely the Trinity and the relationship between God and the cosmos (reality. Futhermore, today there is an emphasis on a new concept of God, known as Panentheism. In this concept, God and his creation are identified with each other. In the South African context, the article deals very shortly with the viewpoints of Spangenberg, Van Aarde and Müller in this regard. The God confessed in the HC is the triune God: Father, Son and Holy Spirit. In the closest and most logical coherence with this, the HC confesses the deity of Christ and of the Holy Spirit. The HC also proceeds from the premise of the historical, bodily resurrection of Christ from the dead. As far as the relationship between God and creation is concerned, the HC, in agreement with the church of the first centuries, confesses and teaches a personal God, the Father of Jesus Christ, who for the sake of Christ is the Father of the elect. This God is the almighty creator of heaven and earth. He lives in a covenant relationship with his creation, which he sustains and governs at every moment. He is both transcendent and immanent.Alhoewel die Heidelbergse Kategismus (HK nie ’n sistematiese Godsleer bevat soos sommige van die ander belydenisskrifte nie en bronne oor die spesifieke onderwerp betreklik skaars is, is dit tog een van die belangrikste onderwerpe wanneer daar oor die teologie van die HK gehandel word (W. van ’t Spijker. Vanweë die voorgeskrewe lengte, word daar in hierdie artikel slegs op twee aspekte van die Godsleer gefokus, naamlik die Drie-eenheid en die verhouding van God tot die kosmos (werklikheid. Hierdie twee aspekte is

  11. New spectral imaging techniques for blood oximetry in the retina

    Alabboud, Ied; Muyo, Gonzalo; Gorman, Alistair; Mordant, David; McNaught, Andrew; Petres, Clement; Petillot, Yvan R.; Harvey, Andrew R.


    Hyperspectral imaging of the retina presents a unique opportunity for direct and quantitative mapping of retinal biochemistry - particularly of the vasculature where blood oximetry is enabled by the strong variation of absorption spectra with oxygenation. This is particularly pertinent both to research and to clinical investigation and diagnosis of retinal diseases such as diabetes, glaucoma and age-related macular degeneration. The optimal exploitation of hyperspectral imaging however, presents a set of challenging problems, including; the poorly characterised and controlled optical environment of structures within the retina to be imaged; the erratic motion of the eye ball; and the compounding effects of the optical sensitivity of the retina and the low numerical aperture of the eye. We have developed two spectral imaging techniques to address these issues. We describe first a system in which a liquid crystal tuneable filter is integrated into the illumination system of a conventional fundus camera to enable time-sequential, random access recording of narrow-band spectral images. Image processing techniques are described to eradicate the artefacts that may be introduced by time-sequential imaging. In addition we describe a unique snapshot spectral imaging technique dubbed IRIS that employs polarising interferometry and Wollaston prism beam splitters to simultaneously replicate and spectrally filter images of the retina into multiple spectral bands onto a single detector array. Results of early clinical trials acquired with these two techniques together with a physical model which enables oximetry map are reported.


    To understand mechanisms of neurotoxicity in susceptible populations, we examined age-related changes in constitutive gene expression in the retinas of young (4mos), middle-aged (11 mos) and aged (23 mos) male Long Evans rats. Derived from a pouch of the forebrain during develop...

  13. Near UV radiation effect on the lens and retina

    The discussion presented in this paper indicates that the retina of a diurnal animal with a natural UV-absorbing lens (ie: the gray squirrel) is susceptible to near-UV damage from environmental sources only after the lens has been removed. This suggests that it is very important to protect against near-UV exposure of human eyes after cataract surgery

  14. Impact of bronchopulmonary dysplasia on brain and retina

    Annie Wing Hoi Poon


    Full Text Available Many premature newborns develop bronchopulmonary dysplasia (BPD, a chronic lung disease resulting from prolonged mechanical ventilation and hyperoxia. BPD survivors typically suffer long-term injuries not only to the lungs, but also to the brain and retina. However, currently it is not clear whether the brain and retinal injuries in these newborns are related only to their prematurity, or also to BPD. We investigated whether the hyperoxia known to cause histologic changes in the lungs similar to BPD in an animal model also causes brain and retinal injuries. Sprague Dawley rat pups were exposed to hyperoxia (95% O2, ‘BPD’ group or room air (21% O2, ‘control’ group from postnatal day 4–14 (P4–14; the rat pups were housed in room air between P14 and P28. At P28, they were sacrificed, and their lungs, brain, and eyes were extracted. Hematoxylin and eosin staining was performed on lung and brain sections; retinas were stained with Toluidine Blue. Hyperoxia exposure resulted in an increased mean linear intercept in the lungs (P<0.0001. This increase was associated with a decrease in some brain structures [especially the whole-brain surface (P=0.02], as well as a decrease in the thickness of the retinal layers [especially the total retina (P=0.0008], compared to the room air control group. In addition, a significant negative relationship was observed between the lung structures and the brain (r=−0.49, P=0.02 and retina (r=−0.70, P=0.0008 structures. In conclusion, hyperoxia exposure impaired lung, brain, and retina structures. More severe lung injuries correlated with more severe brain and retinal injuries. This result suggests that the same animal model of chronic neonatal hyperoxia can be used to simultaneously study lung, brain and retinal injuries related to hyperoxia.

  15. Artificial retina: the multichannel processing of the mammalian retina achieved with a neuromorphic asynchronous light acquisition device.

    Lorach, Henri; Benosman, Ryad; Marre, Olivier; Ieng, Sio-Hoi; Sahel, José A; Picaud, Serge


    Objective. Accurate modeling of retinal information processing remains a major challenge in retinal physiology with applications in visual rehabilitation and prosthetics. Most of the current artificial retinas are fed with static frame-based information, losing thereby the fundamental asynchronous features of biological vision. The objective of this work is to reproduce the spatial and temporal properties of the majority of ganglion cell (GC) types in the mammalian retina. Approach. Here, we combined an asynchronous event-based light sensor with a model pulling nonlinear subunits to reproduce the parallel filtering and temporal coding occurring in the retina. We fitted our model to physiological data and were able to reconstruct the spatio-temporal responses of the majority of GC types previously described in the mammalian retina (Roska et al 2006 J. Neurophysiol. 95 3810-22). Main results. Fitting of the temporal and spatial components of the response was achieved with high coefficients of determination (median R(2) = 0.972 and R(2) = 0.903, respectively). Our model provides an accurate temporal precision with a reliability of only few milliseconds-peak of the distribution at 5 ms-similar to biological retinas (Berry et al 1997 Proc. Natl Acad. Sci. USA 94 5411-16; Gollisch and Meister 2008 Science 319 1108-11). The spiking statistics of the model also followed physiological measurements (Fano factor: 0.331). Significance. This new asynchronous retinal model therefore opens new perspectives in the development of artificial visual systems and visual prosthetic devices. PMID:23075696

  16. Expression of connexin genes in the human retina

    Joussen Antonia


    Full Text Available Abstract Background Gap junction channels allow direct metabolically and electrical coupling between adjacent cells in various mammalian tissues. Each channel is composed of 12 protein subunits, termed connexins (Cx. In the mouse retina, Cx43 could be localized mostly between astroglial cells whereas expression of Cx36, Cx45 and Cx57 genes has been detected in different neuronal subtypes. In the human retina, however, the expression pattern of connexin genes is largely unknown. Methods Northern blot hybridizations, RT-PCR as well as immunofluorescence analyses helped to explore at least partially the expression pattern of the following human connexin genes GJD2 (hCx36, GJC1 (hCx45, GJA9 (hCx59 and GJA10 (hCx62 in the human retina. Results Here we report that Northern blot hybridization signals of the orthologuous hCx36 and hCx45 were found in human retinal RNA. Immunofluorescence signals for both connexins could be located in both inner and outer plexiform layer (IPL, OPL. Expression of a third connexin gene denoted as GJA10 (Cx62 was also detected after Northern blot hybridization in the human retina. Interestingly, its gene structure is similar to that of Gja10 (mCx57 being expressed in mouse horizontal cells. RT-PCR analysis suggested that an additional exon of about 25 kb further downstream, coding for 12 amino acid residues, is spliced to the nearly complete reading frame on exon2 of GJA10 (Cx62. Cx59 mRNA, however, with high sequence identity to zebrafish Cx55.5 was only weakly detectable by RT-PCR in cDNA of human retina. Conclusion In contrast to the neuron-expressed connexin genes Gjd2 coding for mCx36, Gjc1 coding for mCx45 and Gja10 coding for mCx57 in the mouse, a subset of 4 connexin genes, including the unique GJA9 (Cx59 and GJA10 (Cx62, could be detected at least as transcript isoforms in the human retina. First immunofluorescence analyses revealed a staining pattern of hCx36 and hCx45 expression both in the IPL and OPL, partially

  17. The Stuttgart-Heidelberg Model of Active Feedback Driven Quality Management: Means for the Optimization of Psychotherapy Provision

    Hans Kordy


    Full Text Available La gestión de la calidad busca la evaluación del tratamiento psicoterapéutico. Un aspecto central se relaciona con el desarrollo de baterías de evaluación y criterios de evaluación adecuados. El modelo Stuttgart-Heidelberg (S-H representa un sistema que proporciona conceptos, instrumentos psicométricos y un programa informático desarrollado para la gestión de la calidad basada en el feedback activo. La información central del modelo Stuttgart-Heidelberg es el resultado individual del tratamiento. El planteamiento es que la psicoterapia puede mejorarse si proporcionamos información sobre los resultados terapéuticos (en especial los negativos, pues los procesos de solución de problemas se estimularán por el feedback recibido. El presente trabajo presenta un inventario de evaluación, la evaluación estandarizada de los resultados y las diversas herramientas de feedback del modelo SH. Un estudio sistemático incluyendo 1715 pacientes de un hospital especializado en trastornos psicosomáticos documenta la validez de este abordaje. Los resultados empíricos refuerzan una estrategia de transparencia acerca de lo que acontece en la práctica clínica – por ejemplo, acerca de los tratamientos administrados, sus resultados y costos. Implicaciones para la posterior optimización de los servicios de salud son discutidos.

  18. Validation of the prognostic Heidelberg re-irradiation score in an independent mono-institutional patient cohort

    Re-irradiation has been shown to be a valid option with proven efficacy for recurrent high-grade glioma patients. Overall, up to now it is unclear which patients might be optimal candidates for a second course of irradiation. A recently reported prognostic score developed by Combs et al. may guide treatment decisions and thus, our mono-institutional cohort served as validation set to test its relevance for clinical practice. The prognostic score is built upon histology, age (< 50 vs. ≥ 50 years) and the time between initial radiotherapy and re-irradiation (≤ 12 vs. > 12 months). This score was initially introduced to distinguish patients with excellent (0 points), good (1 point), moderate (2 points) and poor (3–4 points) post-recurrence survival (PRS) after re-irradiation. Median prescribed radiation dose during re-treatment of recurrent malignant glioma was 36 Gy in 2 Gy single fractions. A substantial part of the patients was additionally treated with bevacizumab (10 mg/kg intravenously at d1 and d15 during re-irradiation). 88 patients (initially 61 WHO IV, 20 WHO III, 7 WHO II) re-irradiated in a single institution were retrospectively analyzed. Median follow-up was 30 months and median PRS of the entire patient cohort 7 months. Seventy-one patients (80.7%) received bevacizumab. PRS was significantly increased in patients receiving bevacizumab (8 vs. 6 months, p = 0.027, log-rank test). KPS, age, MGMT methylation status, sex, WHO grade and the Heidelberg score showed no statistically significant influence on neither PR-PFS nor PRS. In our cohort which was mainly treated with bevacizumab the usefulness of the Heidelberg score could not be confirmed probably due to treatment heterogeneity; it can be speculated that larger multicentric data collections are needed to derive a more reliable score

  19. The relationship between the numbers of Salmonella Enteritidis, Salmonella Heidelberg, or Salmonella Hadar colonizing reproductive tissues of experimentally infected laying hens and deposition inside eggs

    Contamination of eggs by Salmonella Enteritidis has been a prominent cause of human illness for several decades and is the focus of a recently implemented national regulatory plan for egg-producing flocks in the United States. S. Heidelberg has also been identified as an egg-transmitted pathogen. Th...

  20. The Relationship between the Numbers of Salmonella Enteritidis, S. Heidelberg, or S. Hadar Colonizing Reproductive Tissues of Experimentally Infected Laying Hens and Deposition inside Eggs

    Salmonella deposition inside eggs results from reproductive tract colonization in laying hens. In the present study, groups of hens were orally infected with S. Enteritidis, S. Heidelberg, or S. Hadar. No significant differences were observed between strains in either the frequency or numbers of Sal...

  1. Origins of spontaneous activity in the degenerating retina

    Stuart eTrenholm


    Full Text Available Sensory deafferentation resulting from the loss of photoreceptors during retinal degeneration is often accompanied by a paradoxical increase in spontaneous activity throughout the visual system. Oscillatory discharges are apparent in retinal ganglion cells in several rodent models of retinal degeneration, indicating that spontaneous activity can originate in the retina. Understanding the biophysical mechanisms underlying spontaneous retinal activity is interesting for two main reasons. First, it could lead to strategies that reduce spontaneous retinal activity, which could improve the performance of vision restoration strategies that aim to stimulate remnant retinal circuits in blind patients. Second, studying emergent network activity could offer general insights into how sensory systems remodel upon deafferentation. Here we provide an overview of the work describing spontaneous activity in the degenerating retina, and outline the current state of knowledge regarding the cellular and biophysical properties underlying spontaneous neural activity.

  2. Modeling and Simulation of Microelectrode-Retina Interactions

    Beckerman, M


    The goal of the retinal prosthesis project is the development of an implantable microelectrode array that can be used to supply visually-driven electrical input to cells in the retina, bypassing nonfunctional rod and cone cells, thereby restoring vision to blind individuals. This goal will be achieved through the study of the fundamentals of electrical engineering, vision research, and biomedical engineering with the aim of acquiring the knowledge needed to engineer a high-density microelectrode-tissue hybrid sensor that will restore vision to millions of blind persons. The modeling and simulation task within this project is intended to address the question how best to stimulate, and communicate with, cells in the retina using implanted microelectrodes.

  3. Optical Coherence Tomography and Raman Spectroscopy of the retina

    Evans, J W; Zawadzki, R J; Liu, R; Chan, J; Lane, S; Werner, J S


    Imaging the structure and correlating it with the biochemical content of the retina holds promise for fundamental research and for clinical applications. Optical coherence tomography (OCT) is commonly used to image the 3D structure of the retina and while the added functionality of biochemical analysis afforded by Raman scattering could provide critical molecular signatures for clinicians and researchers, there are many technical challenges to combining these imaging modalities. We present an ex vivo OCT microscope combined with Raman spectroscopy capable of collecting morphological and molecular information about a sample simultaneously. The combined instrument will be used to investigate remaining technical challenges to combine these imaging modalities, such as the laser power levels needed to achieve a Raman signal above the noise level without damaging the sample.

  4. Mesopic Contrast Measured with a Computational Model of the Retina

    Decuypere, Justine; Capron, Jean-Luc; Dutoit, Thierry; Renglet, Michel; CIE Centenary Conference "Towards a New Century of Light"


    This paper presents an image-based approach to lighting design in mesopic lighting conditions. Firstly, we generate a multispectral image of a visual scene from the considered view point (a pedestrian walking along an urban street for example).Secondly, we transform this multispectral image into perception maps using a computational model of the retina. Finally, we analyse those perception maps and compare them by varying parameters in the multispectral image (spectrum of the light source, ph...

  5. Electrical Coupling Between Glial Cells in the Rat Retina

    Ceelen, Paul W.; Lockridge, Amber; Newman, Eric A.


    The strength of electrical coupling between retinal glial cells was quantified with simultaneous whole-cell current-clamp recordings from astrocyte–astrocyte, astrocyte–Müller cell, and Müller cell–Müller cell pairs in the acutely isolated rat retina. Experimental results were fit and space constants determined using a resistive model of the glial cell network that assumed a homogeneous two-dimensional glial syncytium. The effective space constant (the distance from the point of stimulation t...

  6. Electrical coupling between bipolar cells in carp retina

    Kujiraoka, Toru; Saito, Takehiko


    Intracellular recordings were made simultaneously from pairs of neighboring bipolar cells by advancing two independent microelectrodes into retinas of carp (Cyprinus carpio). Bipolar cells were identified by their response properties and in several samples were verified by intracellular injection of Lucifer yellow. Current of either polarity injected into one member of the bipolar cell pair elicited a signconserving, sustained potential change in the other bipolar cell without any significant...

  7. Plastic retina: image enhancement using polymer grid triode arrays

    Heeger, Alan J.; Heeger, David J.; Langan, John D.; Yang, Yang


    An array of polymer grid triodes (PGTs) connected through a common grid functions as a 'plastic retina' which provides local contrast gain control for image enhancement. This device, made from layers of conducting polymers, functions as an active resistive network that performs center-surround filtering. The PGT array with common grid is a continuous analog of the discrete approach of Mead, with a variety of fabrication advantages and with a significant saving of 'real estate' within the unit cell of each pixel.

  8. Mechanisms underlying spontaneous glutamatergic activity in developing mouse retina

    Firl, Alana


    Throughout the developing nervous system, spontaneous oscillatory patterns of activity have been observed. The developing murine retina is no exception, where spontaneous activity manifests as spatially correlated waves of depolarizations. These retinal waves propagate between neighboring neurons within retinal layers during the two postnatal weeks just prior to eye-opening and development of the light response. Waves are necessary for the normal patterning of connections of the retinal proje...

  9. Effects and Responses to Spaceflight in the Mouse Retina

    Zanello, Susana B.; Theriot, Corey; Westby, Christian; Boyle, Richard


    Several stress environmental factors are combined in a unique fashion during spaceflight, affecting living beings widely across their physiological systems. Recently, attention has been placed on vision changes in astronauts returning from long duration missions. Alterations include hyperoptic shift, globe flattening, choroidal folds and optic disc edema, which are probably associated with increased intracranial pressure. These observations justify a better characterization of the ocular health risks associated with spaceflight. This study investigates the impact of spaceflight on the biology of the mouse retina. Within a successful tissue sharing effort, eyes from albino Balb/cJ mice aboard STS-133 were collected for histological analysis and gene expression profiling of the retina at 1 and 7 days after landing. Both vivarium and AEM (Animal Enclosure Module) mice were used as ground controls. Oxidative stress-induced DNA damage was higher in the flight samples compared to controls on R+1, and decreased on R+7. A trend toward higher oxidative and cellular stress response gene expression was also observed on R+1 compared to AEM controls, and these levels decreased on R+7. Several genes coding for key antioxidant enzymes, namely, heme-oxygenase-1, peroxiredoxin, and catalase, were among those upregulated after flight. Likewise, NF B and TGFbeta1, were upregulated in one flight specimen that overall showed the most elevated oxidative stress markers on R+1. In addition, retinas from vivarium control mice evidenced higher oxidative stress markers, NF B and TGFbeta1, likely due to the more intense illumination in vivarium cages versus the AEM. These preliminary data suggest that spaceflight represents a source of environmental stress that translates into oxidative and cellular stress in the retina, which is partially reversible upon return to Earth. Further work is needed to dissect the contribution of the various spaceflight factors (microgravity, radiation) and to

  10. The Retina and Other Light-sensitive Ocular Clocks.

    Besharse, Joseph C; McMahon, Douglas G


    Ocular clocks, first identified in the retina, are also found in the retinal pigment epithelium (RPE), cornea, and ciliary body. The retina is a complex tissue of many cell types and considerable effort has gone into determining which cell types exhibit clock properties. Current data suggest that photoreceptors as well as inner retinal neurons exhibit clock properties with photoreceptors dominating in nonmammalian vertebrates and inner retinal neurons dominating in mice. However, these differences may in part reflect the choice of circadian output, and it is likely that clock properties are widely dispersed among many retinal cell types. The phase of the retinal clock can be set directly by light. In nonmammalian vertebrates, direct light sensitivity is commonplace among body clocks, but in mice only the retina and cornea retain direct light-dependent phase regulation. This distinguishes the retina and possibly other ocular clocks from peripheral oscillators whose phase depends on the pace-making properties of the hypothalamic central brain clock, the suprachiasmatic nuclei (SCN). However, in mice, retinal circadian oscillations dampen quickly in isolation due to weak coupling of its individual cell-autonomous oscillators, and there is no evidence that retinal clocks are directly controlled through input from other oscillators. Retinal circadian regulation in both mammals and nonmammalian vertebrates uses melatonin and dopamine as dark- and light-adaptive neuromodulators, respectively, and light can regulate circadian phase indirectly through dopamine signaling. The melatonin/dopamine system appears to have evolved among nonmammalian vertebrates and retained with modification in mammals. Circadian clocks in the eye are critical for optimum visual function where they play a role fine tuning visual sensitivity, and their disruption can affect diseases such as glaucoma or retinal degeneration syndromes. PMID:27095816

  11. Wnt Signaling in Form Deprivation Myopia of the Mice Retina

    Ma, Mingming; ZHANG, ZHENGWEI; Du, Ergang; Zheng, Wenjing; Gu, Qing; Xu, Xun; Ke, Bilian


    Background The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. Methodology/Principal Findings (1) One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control group...



    Objective To observe the effects of tetramethyipyrazine(TMP) on retina to find out whether it can protect retina from glaucomatous damage. Methods Twenty-four rabbits were randomly divided into four groups. One eye of each rabbit was model eye induced by 2% methylcellulous, and the other was control eye. Normal saline, TMP, timolol and a combination of timolol and TMP were administrated to group A, B, C and D respectively. At the end of 4th week, eyes were excavated for light and electron microscopic study. Results The numbers of ganglion cells (P <0. 01) and bipolar cells (P <0. 01) in model eye were different significantly between group A and B. In group A, the model eye ganglion cells were karyopyknosis, chromatin margination and nuclear membrane rupture; some in ner nuclear cells dcveloped marked lytic changes; outer segment appeared disorganized; but group B changed slight ly. Conclusion The results suggest that TMP may protect retina from glaucomatous damage.

  13. Light pollution: the possible consequences of excessive illumination on retina.

    Contín, M A; Benedetto, M M; Quinteros-Quintana, M L; Guido, M E


    Light is the visible part of the electromagnetic radiation within a range of 380-780 nm; (400-700 on primates retina). In vertebrates, the retina is adapted to capturing light photons and transmitting this information to other structures in the central nervous system. In mammals, light acts directly on the retina to fulfill two important roles: (1) the visual function through rod and cone photoreceptor cells and (2) non-image forming tasks, such as the synchronization of circadian rhythms to a 24 h solar cycle, pineal melatonin suppression and pupil light reflexes. However, the excess of illumination may cause retinal degeneration or accelerate genetic retinal diseases. In the last century human society has increased its exposure to artificial illumination, producing changes in the Light/Dark cycle, as well as in light wavelengths and intensities. Although, the consequences of unnatural illumination or light pollution have been underestimated by modern society in its way of life, light pollution may have a strong impact on people's health. The effects of artificial light sources could have direct consequences on retinal health. Constant exposure to different wavelengths and intensities of light promoted by light pollution may produce retinal degeneration as a consequence of photoreceptor or retinal pigment epithelium cells death. In this review we summarize the different mechanisms of retinal damage related to the light exposure, which generates light pollution. PMID:26541085

  14. Meduloepitelioma teratóide da retina: relato de caso Teratoid medulloepithelioma of the retina: case report

    Ramon Coral Ghanem


    Full Text Available O meduloepitelioma é um tumor intra-ocular congênito originário do epitélio medular primitivo que, por sua vez, é responsável pela formação do epitélio não pigmentado do corpo ciliar. Ocorre geralmente na infância, de forma unilateral, acometendo o corpo ciliar. O objetivo deste trabalho é documentar um caso raro de meduloepitelioma teratóide originário da retina. Paciente de nove anos, feminina, apresentava baixa acuidade visual (AV, estrabismo e leucocoria no olho esquerdo (OE. A AV era de 1,0 no olho direito e movimentos de mão no OE. Foi observada tumoração retrocristaliniana branco-acinzentada no OE, aparentemente subretiniana, vascularizada, de grande extensão, com alterações císticas na sua superfície. Foram realizadas tomografia de crânio e órbitas e ecografia ocular. A paciente foi submetida à enucleação com suspeita clínica de retinoblastoma. Pelo aspecto histopatológico foi feito o diagnóstico de meduloepitelioma teratóide benigno originário da retina. Na maioria dos casos apresentados na literatura o meduloepitelioma tem origem a partir do epitélio não pigmentado do corpo ciliar. No nosso caso, a neoplasia parece ter tido origem a partir da retina, já que os cortes revelaram epitélio do corpo ciliar preservado e não foi reconhecida a estrutura normal da retina. Embora o tumor apresentado neste relato tenha sido classificado como benigno, o fato de ser lesão de grandes proporções e de crescimento aparentemente recente, justifica a conduta cirúrgica empregada. O tratamento do meduloepitelioma deve objetivar a intervenção cirúrgica precoce, na tentativa de se evitar a disseminação extra-ocular.Medulloepithelioma is a congenital intraocular tumor that usually arises from the primitive medullary epithelium that is destined to form the nonpigmented ciliary epithelium of the ciliary body. It occurs most frequently in early childhood and is unilateral. This report documents a rare case of

  15. Remediation measures at the former hazardous waste dump at Malsch near Heidelberg; Sanierung der ehemaligen Sonderabfalldeponie Malsch. Hydrogeologische Bewertung

    Hanstein, P.; Hoetzl, H. [Karlsruhe Univ. (T.H.) (Germany). Lehrstuhl fuer Angewandte Geologie


    The former hazardous waste deposit of Malsch is located south of Heidelberg at the eastern margin of the Upper Rhine Graben. Using a former clay pit about 700.000 m{sup 3} of partly high toxic organic and inorganic wastes were deposited from 1971 to 1984. A leakage from the deposit was first recognised in 1984. Detailed investigation showed that thin channel-like conglomerate layers intercalated in the clays and marls as well as faults are cropping out into the base of the deposit and cause a direct seepage of leachate. Contaminants pollute the downstream area over a distance of 500 m. Remediation measures adding up to 100 Mio. DM were carried out including the construction of a slurry wall encircling laterally the whole site, a surface cover with a multi-liner system as well as a pump and treat system for the leachate was installed and are now in operation. Model studies of the ground water flow including a 3-dimensional site model and a 2-dimensional regional model started during the remediation work. According to the complex geological situation specific procedures was applied to transform the heterogeneous tectonical structure into the numerical models. The balance of water flowing through the deposit was calculated by the piezometric heads to assess different remediation stages. In spite of the missing impervious base the calculation could prove that in connection of a certain pumping rate of the leachate the environment and especially the groundwater can be protected from further leakage. (orig.) [Deutsch] Die fruehere Sonderabfalldeponie Malsch wurde 1971 in einer stillgelegten Tongrube suedlich von Heidelberg am oestlichen Rand des Oberrheingrabens angelegt und bis 1984 betrieben. Insgesamt wurden ueber 700.000 m{sup 3} zum Teil hochtoxische organische und anorganische Sonderabfaelle abgelagert. Mit Abschluss der Deponierungsphase wurden Sickerwasseraustritte im westlichen Deponievorfeld festgelstellt. Ursache fuer die Undichtigkeiten waren geringmaechtige

  16. Antibody to a molecular marker of cell position inhibits synapse formation in retina.

    Trisler, D.; Bekenstein, J; Daniels, M P


    A topographic gradient of TOP molecules in retina can be used to identify neuron position. Antibody to TOP from hybridoma cells that were injected into in vivo embryo eyes diffused into the retina and bound in a topographic gradient of [antibody.TOP] ([Ab.TOP]) complexes. Synapse formation in retina was inhibited in the presence of anti-TOP antibody. This suggests that TOP is involved in synapse formation and that recognition of position by neurons is necessary for normal synapse formation.

  17. Evaluating PcGets and RETINA as Automatic Model Selection Algorithms.

    Jennifer L. Castle


    The paper describes two automatic model selection algorithms, RETINA and PcGets, briefly discussing how the algorithms work and what their performance claims are. RETINA's Matlab implementation of the code is explained, then the program is compared with PcGets on the data in Perez-Amaral, Gallo and White (2005, Econometric Theory, Vol. 21, pp. 262-277), "A Comparison of Complementary Automatic Modelling Methods: RETINA and PcGets", and Hoover and Perez (1999, Econometrics Journal, Vol. 2, pp....

  18. Adenosine as a signaling molecule in the retina: biochemical and developmental aspects



    The nucleoside adenosine plays an important role as a neurotransmitter or neuromodulator in the central nervous system, including the retina. In the present paper we review compelling evidence showing that adenosine is a signaling molecule in the developing retina. In the chick retina, adenosine transporters are present since early stages of development before the appearance of adenosine A1 receptors modulating dopamine-dependent adenylate cyclase activity or A2 receptors that directly activa...

  19. Simulation and performance of an artificial retina for 40 MHz track reconstruction

    We present the results of a detailed simulation of the artificial retina pattern-recognition algorithm, designed to reconstruct events with hundreds of charged-particle tracks in pixel and silicon detectors at LHCb with LHC crossing frequency of 40 MHz. Performances of the artificial retina algorithm are assessed using the official Monte Carlo samples of the LHCb experiment. We found performances for the retina pattern-recognition algorithm comparable with the full LHCb reconstruction algorithm

  20. Dual cameras acquisition and display system of retina-like sensor camera and rectangular sensor camera

    Cao, Nan; Cao, Fengmei; Lin, Yabin; Bai, Tingzhu; Song, Shengyu


    For a new kind of retina-like senor camera and a traditional rectangular sensor camera, dual cameras acquisition and display system need to be built. We introduce the principle and the development of retina-like senor. Image coordinates transformation and interpolation based on sub-pixel interpolation need to be realized for our retina-like sensor's special pixels distribution. The hardware platform is composed of retina-like senor camera, rectangular sensor camera, image grabber and PC. Combined the MIL and OpenCV library, the software program is composed in VC++ on VS 2010. Experience results show that the system can realizes two cameras' acquisition and display.

  1. Comparison of fluorescein angiography with microvascular anatomy of macaque retinas.

    Weinhaus, R S; Burke, J M; Delori, F C; Snodderly, D M


    Recent anatomic work has shown that the capillary network of the fovea is multilaminar. We have identified the elements of this network that are visualized by fluorescein angiography and those that are missed. Fluorescein angiograms of monkey retinas (Macaca fascicularis) with good visualization of individual capillaries were obtained by standard clinical techniques. Retinal whole mounts were prepared from the same animals. Anatomic drawings made from the whole mounts were used to identify which parts of the capillary network were visualized angiographically. Angiographic estimates of dimensions of the foveal avascular zone corresponded closely to the anatomy. Capillary visibility declined rapidly from near perfect visualization at the edge of the foveal avascular zone to less than 40% by 900 microns eccentricity. While all the widest capillary segments (diameter 6.1-7.0 microns) were visualized, only 43% of the modal group of capillary segments (diameter 4.1-4.5 microns) were detected. When a relatively homogeneous population of capillaries was analyzed (diameters limited to the narrow range of 4.0-5.0 microns), visualization declined monotonically with depth in the retina. Capillary segments in the nerve fiber plane were visualized more than four times as effectively as segments of comparable diameter in the deepest vascular plane. High quality angiograms accurately delineate the foveal avascular zone, but they visualize only a fraction of the adjacent multilaminar network. Therefore, current techniques may not detect the earliest nonperfusion of capillaries in vaso-occlusive diseases. Capillary visibility is a joint function of diameter and of retinal depth. The decline in visualization with retinal depth implies that light scattering in the retina degrades the angiographic image. PMID:7556462

  2. Survey of intravitreal injection techniques among retina specialists in Israel

    Segal O


    Full Text Available Ori Segal,1,2 Yael Segal-Trivitz,1,3 Arie Y Nemet,1,2 Noa Geffen,1,2 Ronit Nesher,1,2 Michael Mimouni4 1Department of Ophthalmology, Meir Medical Center, Kfar Saba, 2The Sackler School of Medicine, Tel Aviv University, Tel Aviv, 3Department of Psychiatry, Geha Psychiatric Hospital, Petah Tikva, 4Department of Ophthalmology, Rambam Health Care Campus, Haifa, Israel Purpose: The purpose of this study was to describe antivascular endothelial growth factor intravitreal injection techniques of retinal specialists in order to establish a cornerstone for future practice guidelines. Methods: All members of the Israeli Retina Society were contacted by email to complete an anonymous, 19-question, Internet-based survey regarding their intravitreal injection techniques. Results: Overall, 66% (52/79 completed the survey. Most (98% do not instruct patients to discontinue anticoagulant therapy and 92% prescribe treatment for patients in the waiting room. Three quarters wear sterile gloves and prepare the patient in the supine position. A majority (71% use sterile surgical draping. All respondents apply topical analgesics and a majority (69% measure the distance from the limbus to the injection site. A minority (21% displace the conjunctiva prior to injection. A majority of the survey participants use a 30-gauge needle and the most common quadrant for injection is superotemporal (33%. Less than half routinely assess postinjection optic nerve perfusion (44%. A majority (92% apply prophylactic antibiotics immediately after the injection. Conclusion: The majority of retina specialists perform intravitreal injections similarly. However, a relatively large minority performs this procedure differently. Due to the extremely low percentage of complications, it seems as though such differences do not increase the risk. However, more evidence-based medicine, a cornerstone for practice guidelines, is required in order to identify the intravitreal injection techniques

  3. Pbx homeodomain proteins pattern both the zebrafish retina and tectum

    Stout Jennifer


    Full Text Available Abstract Background Pbx genes encode TALE class homeodomain transcription factors that pattern the developing neural tube, pancreas, and blood. Within the hindbrain, Pbx cooperates with Hox proteins to regulate rhombomere segment identity. Pbx cooperates with Eng to regulate midbrain-hindbrain boundary maintenance, and with MyoD to control fast muscle cell differentiation. Although previous results have demonstrated that Pbx is required for proper eye size, functions in regulating retinal cell identity and patterning have not yet been examined. Results Analysis of retinal ganglion cell axon pathfinding and outgrowth in pbx2/4 null embryos demonstrated a key role for pbx genes in regulating neural cell behavior. To identify Pbx-dependent genes involved in regulating retino-tectal pathfinding, we conducted a microarray screen for Pbx-dependent transcripts in zebrafish, and detected genes that are specifically expressed in the eye and tectum. A subset of Pbx-dependent retinal transcripts delineate specific domains in the dorso-temporal lobe of the developing retina. Furthermore, we determined that some Pbx-dependent transcripts also require Meis1 and Gdf6a function. Since gdf6a expression is also dependent on Pbx, we propose a model in which Pbx proteins regulate expression of the growth factor gdf6a, which in turn regulates patterning of the dorso-temporal lobe of the retina. This, in concert with aberrant tectal patterning in pbx2/4 null embryos, may lead to the observed defects in RGC outgrowth. Conclusion These data define a novel role for Pbx in patterning the vertebrate retina and tectum in a manner required for proper retinal ganglion cell axon outgrowth.

  4. Temporal order of bipolar cell genesis in the neural retina

    Chen C-M Amy


    Full Text Available Abstract Background Retinal bipolar cells comprise a diverse group of neurons. Cone bipolar cells and rod bipolar cells are so named for their connections with cone and rod photoreceptors, respectively. Morphological criteria have been established that distinguish nine types of cone bipolar cells and one type of rod bipolar cell in mouse and rat. While anatomical and physiological aspects of bipolar types have been actively studied, little is known about the sequence of events that leads to bipolar cell type specification and the potential relationship this process may have with synapse formation in the outer plexiform layer. In this study, we have examined the birth order of rod and cone bipolar cells in the developing mouse and rat in vivo. Results Using retroviral lineage analysis with the histochemical marker alkaline phosphatase, the percentage of cone and rod bipolar cells born on postnatal day 0 (P0, P4, and P6 were determined, based upon the well characterized morphology of these cells in the adult rat retina. In this in vivo experiment, we have demonstrated that cone bipolar genesis clearly precedes rod bipolar genesis. In addition, in the postnatal mouse retina, using a combination of tritiated-thymidine birthdating and immunohistochemistry to distinguish bipolar types, we have similarly found that cone bipolar genesis precedes rod bipolar genesis. The tritiated-thymidine birthdating studies also included quantification of the birth of all postnatally generated retinal cell types in the mouse. Conclusion Using two independent in vivo methodologies in rat and mouse retina, we have demonstrated that there are distinct waves of genesis of the two major bipolar cell types, with cone bipolar genesis preceding rod bipolar genesis. These waves of bipolar genesis correspond to the order of genesis of the presynaptic photoreceptor cell types.

  5. Development of Recombinant Flagellar Antigens for Serological Detection of Salmonella enterica Serotypes Enteritidis, Hadar, Heidelberg, and Typhimurium in Poultry

    Charles L. Hofacre


    Full Text Available Accurate and fast detection of harmful Salmonella is a major concern of food safety. Common Salmonella serotypes responsible for human associated foodborne outbreaks are S. Enteritidis, S. Hadar, S. Heidelberg, and S. Typhimurium are also commonly isolated from poultry. Serology is commonly used to monitor disease in poultry, therefore application of Salmonella serotype-specific test will have added value in Salmonella surveillance or monitoring vaccine efficacy. Recombinant flagellins were purified to be used as antigens in an ELISA. In this study, an ELISA was developed for the serological detection of S. Enteritidis. Once optimized, 500 ng of purified recombinant S. Enteritidis flagellin and a 1:64 dilution were determined to be optimal for testing sera. A negative baseline cutoff was calculated to be an optical density (OD of 0.35. All sera from birds with history of S. Enteritidis exposure tested positive and all sera from chickens with no exposure tested negative to this Salmonella serotype. Current ELISA for serological detection of Salmonella suffers from cross reactivity inherent in lipopolysaccharide (LPS or whole cell antigen based serological tests. This new ELISA eliminates common cross reactivity by focusing specifically on the flagellins of the Salmonella serotypes common in poultry and associated with foodborne outbreaks.

  6. Study of the spontaneous fission of 252Cf at the Darmstadt-Heidelberg Crystal-Ball Spectrometer

    This work was performed at the Darmstadt-Heidelberg Crystal-Ball Spectrometer, a 4π detector with good efficiency for gamma quanta and neutrons consisting of 162 NaI single counters. By means of a semiconductor counter and a 2π parallel-plate heavy-ion detector the mass of the fission fragments could be determined with a mean mass resolution of 3 mass units. It was the aim of the thesis to contribute by a large number of single quantities and correlations between these parameters to a better understanding of the fission process. A comparison of the results with reliable literature data resulted a very sufficient agreement. Interesting results were shown above all in the correlations between the gamma respectively neutron emission and the fragment mass respectively the total kinetic energy (TKE): The saw-tooth shaped slope of the gamma multiplicity with the mass known from literature was disproved by means of the Doppler-shift method. The single energy spectrum of the gamma quanta shows for different energy ranges a very different mass dependence. In the region of symmetric fragmentation a new high-energetic gamma component was found. The dependence of the neutron multiplicity on the TKE is for fixed mass partition within the error limits linear. The changes of the gradiation of this straight line with the mass allows far reaching predictions about the shape of the nucleus immediately before the fission. The neutron saw-tooth exists also for high internal excitation energies. (orig.)

  7. Status of the 7 MeV/u, 217 MHz Injector Linac for the Heidelberg Cancer Therapy Facility

    Schlitt, B; Hutter, G; Klos, F; Lu, Y; Minaev, S A; Mühle, C; Ratzinger, U; Schlitt, B; Tiede, R; Vinzenz, W; Will, C; Zurkan, O


    A clinical synchrotron facility for cancer therapy using energetic proton and ion beams (C, He and O) is under construction and will be installed at the Radiologische Universitätsklinik in Heidelberg, Germany, starting in 2005. The status of the ECR ion source systems, the beam line components of the low energy beam transport lines, the 400 keV/u RFQ and the 20 MV IH-cavity as well as the linac rf system will be reported. Two prototype magnets of the linac quadrupole magnets have been built at GSI and have been tested successfully. A test bench for the 1.4 MW, 217 MHz cavity amplifier built by industry has been installed at GSI including a 120 kW driver amplifier which will be used also for high power tests of the RFQ. A test bench for the RFQ using proton beams is presently being set up at the IAP. RF tuning of the 1:2 scaled IH-DTL model as well as Microwave Studio simulations of the model and the power cavity have been also performed at the IAP [1].




    Full Text Available Gyrate atrophy of the choroid and retina is a rare chorioretinal degeneration inherited by on autosonal recessive mode of transmission. It is caused by mutation in gene for ornithine aminotransferase (OAT, located on chromosome 10. It is characterised by high myopia with astigmatism, night blindness during 2 nd and 3 rd decade with a slowly progressive posterior sub capsular cataract. Once diagnosed paediatrician/physician and Ophthalmologist should be aware of the follow up. No single therapy has been shown to halt the progression of the disease.

  9. Delayed response of the retina after hyperbaric oxygen exposure

    Kofoed, Peter Kristian; Hasler, Pascal W; Sander, Birgit;


    examined using multifocal electroretinography (mfERG) and optical coherence tomography (OCT) at baseline and following a course of five consecutive daily sessions of exposure to HBO at 2.4 atmospheres of absolute pressure lasting 90 min each. Results: After HBO, P1 implicit times of the mfERG were.......020). The bulk of the response to HBO was found in the foveal and parafoveal regions. No detectable change was seen in mfERG amplitudes or in the volume or thickness of the retina. Conclusion: A mfERG component related to bipolar and Müller cell function was accelerated by a short intermittent exposure to...

  10. Specifying and controlling the optical image on the human retina.

    Westheimer, Gerald


    A review covering the trends that led to the current state of knowledge in the areas of: (a) schematic models of the eye, and the definition of the retinal image in terms of first-order optics; (b) the description of the actual image on the retina and methods for accessing and characterizing it; (c) available procedures for controlling the quality of the retinal image in defined situations; and (d) intra-receptoral optical effects that cause differences between the light distribution on the retinal surface and at the level of interaction with photopigment molecules. PMID:16099192

  11. Instant website optimization for retina displays how-to

    Larson, Kyle J


    Written in an accessible and practical manner which quickly imparts the knowledge you want to know. As a How-to book it will use applied examples and teach you to optimize websites for retina displays. This book is for web designers and developers who are familiar with HTML, CSS, and editing graphics who would like to improve their existing website or their next web project with high-resolution images. You'll need to have a high-definition device to be able to test the examples in this book and a server to upload your code to if you're not developing it on that device.

  12. Specifying and controlling the optical image on the human retina.

    Westheimer, Gerald


    A review covering the trends that led to the current state of knowledge in the areas of: (a) schematic models of the eye, and the definition of the retinal image in terms of first-order optics; (b) the description of the actual image on the retina and methods for accessing and characterizing it; (c) available procedures for controlling the quality of the retinal image in defined situations; and (d) intra-receptoral optical effects that cause differences between the light distribution on the r...

  13. Macular grid photocoagulation. An experimental study on the primate retina

    Wilson, D.J.; Finkelstein, D.; Quigley, H.A.; Green, W.R.


    We studied the effect of macular grid photocoagulation on the retinal vessels, retina, retinal pigment epithelium, and choroid of normal cynomolgus monkeys. Argon blue-green laser photocoagulation, similar to that employed for treating macular edema due to branch retinal vein occlusion, resulted in a decreased retinal capillary area at both one and five months after treatment. The photoreceptors and retinal pigment epithelium between laser lesions were altered at three days after treatment, but their appearance returned to normal by five months. The significance of these findings is discussed with regard to resolution of macular edema and improvement in vision following grid photocoagulation.

  14. Exploration of Halley's Comet. Based on the 20th ESLAB Symposium, held in Heidelberg, F.R. Germany, 27 - 31 October 1986.

    Grewing, M.; Praderie, F.; Reinhard, R.

    This book contains all the papers that originally appeared in the Comet Halley dedicated issue to the journal Astronomy and Astrophysics, Vol. 187, No. 1/2 (1987) (see 44.003.013) and, in addition, a summary of the scientific results presented at the Heidelberg conference and give papers providing background information on the various space missions to Halley's Comet and the International Halley Watch - see abstracts 011.046, 013.115, 051.064 - 051.67.

  15. Heidelberger Poetikdozentur 2014 - Wilhelm Genazino: Das Eine folgt richtig auf das Andere – Die Form oder wie etwas in die Welt tritt

    Genazino, Wilhelm


    Der Schriftsteller Wilhelm Genazino übernahm zwischen dem 23. Mai und 10. Juni 2014 die Poetikdozentur an der Universität Heidelberg. Im Mittelpunkt des vom Germanistischen Seminar organisierten Veranstaltungsprogramms standen drei öffentliche Poetikvorträge, in denen sich Genazino mit seinem literarischen Schreiben auseinandersetzte. "Das Eine folgt richtig auf das Andere – Die Form oder wie etwas in die Welt tritt" war der letzte der drei Vorträge, die der Schriftsteller im Rahmen der Poeti...

  16. Cell size, number and density in the retina ganglion cell layer of Pekin duck retina at different embryonic age

    ZUO Shi-Feng; CHEN Yao-Xing; WANG Zi-Xu; Cao, Jing; Dong, Yu-lan


    Changes in cell size, number and density of the ganglion cell layer(GCL)of the Pekin duck retina were studied by using the methods of Nissl-staining and Scion Image picture processing at embryonic age day-11,14,17,20,23 and 26. The result indicated that the cells in GCL were small and round uniformly at E11 and E14. The large cells were first found at E17. From E11 to E26, cell size was increased 1.97-fold in the central area (CA) and 3.1-fold in the temple periphery (TP), and there was si...

  17. Pharmacological analysis of intrinsic neuronal oscillations in rd10 retina.

    Sonia Biswas

    Full Text Available In the widely used mouse model of retinal degeneration, rd1, the loss of photoreceptors leads to rhythmic electrical activity of around 10-16 Hz in the remaining retinal network. Recent studies suggest that this oscillation is formed within the electrically coupled network of AII amacrine cells and ON-bipolar cells. A second mouse model, rd10, displays a delayed onset and slower progression of degeneration, making this mouse strain a better model for human retinitis pigmentosa. In rd10, oscillations occur at a frequency of 3-7 Hz, raising the question whether oscillations have the same origin in the two mouse models. As rd10 is increasingly being used as a model to develop experimental therapies, it is important to understand the mechanisms underlying the spontaneous rhythmic activity. To study the properties of oscillations in rd10 retina we combined multi electrode recordings with pharmacological manipulation of the retinal network. Oscillations were abolished by blockers for ionotropic glutamate receptors and gap junctions. Frequency and amplitude of oscillations were modulated strongly by blockers of inhibitory receptors and to a lesser extent by blockers of HCN channels. In summary, although we found certain differences in the pharmacological modulation of rhythmic activity in rd10 compared to rd1, the overall pattern looked similar. This suggests that the generation of rhythmic activity may underlie similar mechanisms in rd1 and rd10 retina.

  18. Survey of intravitreal injection techniques among retina specialists in Israel

    Segal, Ori; Segal-Trivitz, Yael; Nemet, Arie Y; Geffen, Noa; Nesher, Ronit; Mimouni, Michael


    Purpose The purpose of this study was to describe antivascular endothelial growth factor intravitreal injection techniques of retinal specialists in order to establish a cornerstone for future practice guidelines. Methods All members of the Israeli Retina Society were contacted by email to complete an anonymous, 19-question, Internet-based survey regarding their intravitreal injection techniques. Results Overall, 66% (52/79) completed the survey. Most (98%) do not instruct patients to discontinue anticoagulant therapy and 92% prescribe treatment for patients in the waiting room. Three quarters wear sterile gloves and prepare the patient in the supine position. A majority (71%) use sterile surgical draping. All respondents apply topical analgesics and a majority (69%) measure the distance from the limbus to the injection site. A minority (21%) displace the conjunctiva prior to injection. A majority of the survey participants use a 30-gauge needle and the most common quadrant for injection is superotemporal (33%). Less than half routinely assess postinjection optic nerve perfusion (44%). A majority (92%) apply prophylactic antibiotics immediately after the injection. Conclusion The majority of retina specialists perform intravitreal injections similarly. However, a relatively large minority performs this procedure differently. Due to the extremely low percentage of complications, it seems as though such differences do not increase the risk. However, more evidence-based medicine, a cornerstone for practice guidelines, is required in order to identify the intravitreal injection techniques that combine safety and efficacy while causing as little discomfort to the patients as possible. PMID:27366050

  19. Impact of bronchopulmonary dysplasia on brain and retina.

    Poon, Annie Wing Hoi; Ma, Emilie Xiao Hang; Vadivel, Arul; Jung, Suna; Khoja, Zehra; Stephens, Laurel; Thébaud, Bernard; Wintermark, Pia


    Many premature newborns develop bronchopulmonary dysplasia (BPD), a chronic lung disease resulting from prolonged mechanical ventilation and hyperoxia. BPD survivors typically suffer long-term injuries not only to the lungs, but also to the brain and retina. However, currently it is not clear whether the brain and retinal injuries in these newborns are related only to their prematurity, or also to BPD. We investigated whether the hyperoxia known to cause histologic changes in the lungs similar to BPD in an animal model also causes brain and retinal injuries. Sprague Dawley rat pups were exposed to hyperoxia (95% O2, 'BPD' group) or room air (21% O2, 'control' group) from postnatal day 4-14 (P4-14); the rat pups were housed in room air between P14 and P28. At P28, they were sacrificed, and their lungs, brain, and eyes were extracted. Hematoxylin and eosin staining was performed on lung and brain sections; retinas were stained with Toluidine Blue. Hyperoxia exposure resulted in an increased mean linear intercept in the lungs (Panimal model of chronic neonatal hyperoxia can be used to simultaneously study lung, brain and retinal injuries related to hyperoxia. PMID:26988760

  20. Three dimensional reconstruction of tomographic images of the retina

    The development of a new display system for the three-dimensional visualization of tomographic images in ophthalmology. Specifically, a system that can use stacks of B-mode scans from an ultrahigh resolution optical tomography examination to vividly display retinal specimens as three-dimensional objects. Several subroutines were programmed in the rendering and raytracing program Cinema 4D XL 9.102 Studio Bundle (Maxon Computer Inc., Friedrichsburg, Germany), which could process stacks of tomographic scans into three-dimensional objects. Ultrahigh resolution optical coherence tomography examinations were performed on patients with various retinal pathologies and post processed with the subroutines that had been designed. All ultrahigh resolution optical coherence tomographies were performed with a titanium: sapphire based ultra broad bandwidth (160 nm) femtosecond laser system (INTEGRAL, Femtolasers Productions GmbH. Vienna Austria) with an axial resolution of 3 μm. A new three dimensional display system for tomographic images in ophthalmology was developed, which allows a highly vivid display of physiological and pathological structures of the retina. The system also distinguishes itself through its high interactivity and adaptability. This new display system allows the visualization of physiological and pathological structures of the retina in a new way, which will give us new insight into their morphology and development. (author)

  1. An experimental platform for systemic drug delivery to the retina.

    Campbell, Matthew


    Degenerative retinopathies, including age-related macular degeneration, diabetic retinopathy, and hereditary retinal disorders--major causes of world blindness--are potentially treatable by using low-molecular weight neuroprotective, antiapoptotic, or antineovascular drugs. These agents are, however, not in current systemic use owing to, among other factors, their inability to passively diffuse across the microvasculature of the retina because of the presence of the inner blood-retina barrier (iBRB). Moreover, preclinical assessment of the efficacies of new formulations in the treatment of such conditions is similarly compromised. We describe here an experimental process for RNAi-mediated, size-selective, transient, and reversible modulation of the iBRB in mice to molecules up to 800 Da by suppression of transcripts encoding claudin-5, a protein component of the tight junctions of the inner retinal vasculature. MRI produced no evidence indicative of brain or retinal edema, and the process resulted in minimal disturbance of global transcriptional patterns analyzed in neuronal tissue. We show that visual function can be improved in IMPDH1(-\\/-) mice, a model of autosomal recessive retinitis pigmentosa, and that the rate of photoreceptor cell death can be reduced in a model of light-induced retinal degeneration by systemic drug delivery after reversible barrier opening. These findings provide a platform for high-throughput drug screening in models of retinal degeneration, and they ultimately could result in the development of a novel "humanized" approach to therapy for conditions with little or no current forms of treatment.

  2. Rod photoreceptors express GPR55 in the adult vervet monkey retina

    Bouskila, Joseph; Javadi, Pasha; Casanova, Christian;


    components (Müller cells). The aim of this study was to determine the expression pattern of GPR55 in the monkey retina by using confocal microscopy. Our results show that GPR55 is strictly localized in the photoreceptor layer of the extrafoveal portion of the retina. Co-immunolabeling of GPR55 with rhodopsin...

  3. Protein changes in the retina following experimental retinal detachment in rabbits

    Mandal, Nakul; Lewis, Geoffrey P; Fisher, Steven K; Heegaard, Steffen; Prause, Jan U; la Cour, Morten; Vorum, Henrik; Honoré, Bent


    Retinal detachment leads to the widespread cellular remodeling of the retina. The purpose of this study was to identify protein changes that accompany these cellular alterations by comparing the proteomic profiles of sham and experimentally detached rabbit retina. Elucidation of the proteins most...

  4. Ontogenetic expression of the Otx2 and Crx homeobox genes in the retina of the rat

    Rath, Martin F; Morin, Fabrice; Shi, Qiong;


    confirmed the presence of Otx2 mRNA in both the embryonic retinal pigment epithelium and the developing neural retina. During development, the expression of Otx2 persists in the pigment epithelium, whereas Otx2 expression of the neural retina becomes progressively restricted to the outer nuclear layer and...

  5. In vivo cellular visualization of the human retina using optical coherence tomography and adaptive optics

    Olivier, S S; Jones, S M; Chen, D C; Zawadzki, R J; Choi, S S; Laut, S P; Werner, J S


    Optical coherence tomography (OCT) sees the human retina sharply with adaptive optics. In vivo cellular visualization of the human retina at micrometer-scale resolution is possible by enhancing Fourier-domain optical-coherence tomography with adaptive optics, which compensate for the eye's optical aberrations.

  6. Cell size, number and density in the retina ganglion cell layer of Pekin duck retina at different embryonic age

    ZUO Shi-Feng


    Full Text Available Changes in cell size, number and density of the ganglion cell layer(GCL)of the Pekin duck retina were studied by using the methods of Nissl-staining and Scion Image picture processing at embryonic age day-11,14,17,20,23 and 26. The result indicated that the cells in GCL were small and round uniformly at E11 and E14. The large cells were first found at E17. From E11 to E26, cell size was increased 1.97-fold in the central area (CA and 3.1-fold in the temple periphery (TP, and there was significant difference among all embryonic ages. During the growth and development of embryo, the total number of cells in GCL was increased to 2.03×106 cells at E17, and then decreased significantly with age. Differentiation of the central-peripheral gradient in cell density has been performed at E11. Cell density in CA was up to the maximal value (2.54×104 cells/mm2 at E17 and then decreased. However, cell density was decreased constantly in the peripheral area, especially in TP. In conclusion, E17 is the most important point for the retina during the embryonic developmental of Pekin duck, accompanying changes in cell size, number and density in GCL [Acta Zoologica Sinica 54(6: 1082 – 1088, 2008].

  7. The impact of social status inconsistency on cardiovascular risk factors, myocardial infarction and stroke in the EPIC-Heidelberg cohort

    Hermann Silke


    Full Text Available Abstract Background Social inequalities in cardiovascular diseases are well documented. Yet, the relation of social status inconsistency (having different ranks in two or more status indicators like education, occupational position or income and medical conditions of heart or vessels is not clear. Status inconsistency (SI is assumed to be stressful, and the association of psychosocial distress and health is well known. Therefore, we aimed to analyze the relationship between cardiovascular diseases (CVD and status inconsistency. Another target was to assess the influence of behaviour related risk factors on this association. Methods 8960 men and 6070 women, aged 45-65 years, from the EPIC-Heidelberg cohort (European Prospective Investigation into Cancer and Nutrition were included. Socio-economic status was assessed by education/vocational training and occupational position at recruitment. During a median follow-up of 8.7 years, information on CVD was collected. Results Compared to status consistent subjects, men who were in a higher occupational position than could be expected given their educational attainment had a nearly two-fold increased incidence of CVD (Odds Ratio (OR = 1.8, 95% Confidence Interval (CI = 1.5; 2.4, adjusted for age. Smoking behaviour and BMI differed significantly between those who had adequate occupational positions and those who did not. Yet, these lifestyle factors, as opposed to age, did not contribute to the observed differences in CVD. No association of cardiovascular diseases and status inconsistency was found for women or in cases where education exceeded occupational position. Conclusions Status inconsistent men (occupational position > education had a higher risk of cardiovascular diseases than status consistent men. However, harmful behaviour did not explain this relationship.

  8. Infection of Murine Macrophages by Salmonella enterica Serovar Heidelberg Blocks Murine Norovirus Infectivity and Virus-induced Apoptosis.

    Sudhakar S Agnihothram

    Full Text Available Gastroenteritis caused by bacterial and viral pathogens constitutes a major public health threat in the United States accounting for 35% of hospitalizations. In particular, Salmonella enterica and noroviruses cause the majority of gastroenteritis infections, with emergence of sporadic outbreaks and incidence of increased infections. Although mechanisms underlying infections by these pathogens have been individually studied, little is known about the mechanisms regulating co-infection by these pathogens. In this study, we utilized RAW 264.7 murine macrophage cells to investigate the mechanisms governing co-infection with S. enterica serovar Heidelberg and murine norovirus (MNV. We demonstrate that infection of RAW 264.7 cells with S. enterica reduces the replication of MNV, in part by blocking virus entry early in the virus life cycle, and inducing antiviral cytokines later in the infection cycle. In particular, bacterial infection prior to, or during MNV infection affected virus entry, whereas MNV entry remained unaltered when the virus infection preceded bacterial invasion. This block in virus entry resulted in reduced virus replication, with the highest impact on replication observed during conditions of co-infection. In contrast, bacterial replication showed a threefold increase in MNV-infected cells, despite the presence of antibiotic in the medium. Most importantly, we present evidence that the infection of MNV-infected macrophages by S. enterica blocked MNV-induced apoptosis, despite allowing efficient virus replication. This apoptosis blockade was evidenced by reduction in DNA fragmentation and absence of poly-ADP ribose polymerase (PARP, caspase 3 and caspase 9 cleavage events. Our study suggests a novel mechanism of pathogenesis whereby initial co-infection with these pathogens could result in prolonged infection by either of these pathogens or both together.

  9. Caracterización del cemento dental del perro mediante microscopía electrónica de barrido Characterization of dog dental cementum by scanning electron microscopy

    P.G. Toriggia


    Full Text Available El objetivo del trabajo fue caracterizar el cemento dental en el perro utilizando para ello el microscopio electrónico de barrido (MEB. La cara vestibular de 38 raíces dentales fue observada y fotografiada con el MEB, en sus tercios coronario y apical. Se realizó una clasificación morfológica de la superficie y se midió en cada microfotografía el diámetro de 20 fibras de Sharpey, estableciéndose el porcentaje que ocupaban en 600 µm². En el tercio coronario se encontró un cemento de tipo acelular, con fibras de Sharpey densamente agrupadas, proyectándose perpendicularmente a la superficie, ocupando casi su totalidad. El diámetro de las fibras fue de 5.31 ± 0.98 µm. En el tercio apical, se encontró un cemento celular con una densidad de fibras de Sharpey menor al 55%, siendo el resto fibras intrínsecas y lagunas celulares. El diámetro de las fibras fue de 5.47 ± 1.31 µm. Los diámetros de las fibras de Sharpey del tercio apical fueron significativamente mayores (p=0.0000 que aquellos del tercio coronario. Concluimos que la superficie del cemento del perro no es uniforme en toda su extensión, presentando variaciones entre los tercios coronario y apical, así como también dentro del mismo tercio del diente.The aim of this study was to characterize the dental cementum in the dog using the scanning electron microscope (SEM. The buccal surface of 38 dental roots was observed and photographed with the SEM in their coronal and apical thirds. A morphological classification of the surface was performed and also, the diameter of 20 Sharpey fibers was measured in each picture establishing the percentage occupied by them in 600 µm². In the coronal third, acellular cementum was found with the Sharpey fibers closely packed, projecting perpendicular to the surface, occupying almost the whole of it. The diameter of the fibers was of 5.31 ± 0.98 µm. In the apical third, cellular cementum was found, with a density of Sharpey fibers less

  10. Papel del agua en la gelatinización delalmidón de maíz: estudio por calorimetríadiferencial de barrido Role of water in maize starch gelatinization: an study by Differential Scanning Calorimetry

    P. Pineda–Gómez


    Full Text Available El comportamiento térmico del almidón de maíz (Sigma Aldrich se estudió através de calorimetría diferencial de barrido (DSC. El pico endotérmico observadoen el perfil DSC se asocia al proceso de transición de gelatinizacióndel almidón. La fase inicial del proceso y el rango en el que éste ocurre, está gobernada principalmente por la concentración del almidón en solución. Enesta investigación se demuestra que los parámetros relacionados con el métodode observación, en un análisis de DSC influyen al momento de determinar lagelatinización del almidón de maíz. De esta forma, la temperatura del picode transición, la entalpía de gelatinización y el intervalo de temperatura degelatinización son los parámetros en estudio cuando se varía la humedad dela muestra y velocidad de calentamiento con un tamaño de grano homogéneo.Para los análisis, se tomaron valores de humedad de 60, 65, 70, 75 y 80%(p/p, para una velocidad de calentamiento de 2, 5 y 10◦C/min. De igualmodo, para un valor fijo de humedad (80%, se utilizó una velocidad de calentamientode 2, 5, 7, 10 y 15◦C/min. Los resultados indican que la cantidad deagua influye significativamente sobre la entalpía de gelatinización del proceso,pero la temperatura del pico Tp de la endoterma se mantiene constante. Elvalor de la entalpía disminuye a medida que la cantidad de agua aumenta.Las variaciones también son dependientes de la rapidez con que se efectúa latransformación. Los análisis permitieron corroborar, que esta transición en elalmidón es dependiente de factores extrínsecos durante el proceso. Este conocimientosobre la gelatinización del almidón es útil para optimizar procesosindustriales derivados de éste.The thermal behavior of corn starch (Sigma Aldrich was studied by differential scanning calorimetry (DSC. The endothermic peak in the DSC thermogram is associated to the starch gelatinization transition process. Initial phase of process and range in

  11. Comparación de guantes de látex de uso clínico de diferentes marcas comerciales mediante microscopía electrónica de barrido

    Gilberto González


    Full Text Available Resumen (español El uso de guantes de látex representa la primera barrera contra patógenos por parte del personal de ciencias de la salud, sin embargo, es cotidiano escuchar quejas sobre la calidad de los mismos, ya que en algunos casos tienden a romperse con facilidad disminuyendo así su capacidad protectora, además de utilizar como lubricante almidón de maíz, sustancia que puede provocar alergias. En esta investigación se compararon las características morfológicas del látex y la composición química del polvo de guantes de látex de uso clínico, de cinco marcas comerciales mediante microscopia electrónica de barrido. La calidad protectora se estableció como un arreglo entre el promedio de poros, el diámetro de los mismos y la rugosidad de la superficie. La marca Sensimedical® conto con poros de menor diámetro entre 0,1–0,7 μm, un promedio de 36,7 y superficie poco rugosa, seguida por las marcas Mc medical®, Confit®, King® y por ultimo Medac® con poros entre 0,6-2μm, un promedio de 28,1 y superficie muy rugosa. En cuanto a la composición química elemental del polvo lubricante se encontró predominio de calcio, níquel, magnesio y sodio. La presencia del sodio y magnesio puede deberse a mejorar propiedades de sudoración del usuario, pero el níquel puede generar alergias. Además otros elementos en baja proporción considerados contaminantes. Abstract (english The use of latex gloves is the first barrier against pathogens from the staff of health sciences, however, it is commonplace to hear complaints about the quality of them, since in some cases tend to break easily thus reducing their protective capacity, besides using corn starch as a lubricant, a substance that can cause allergies. In this research the morphological characteristics of latex and chemical composition of the powder latex gloves for clinical use, five trademarks by scanning electron microscopy were compared. The protective quality was established

  12. Pixel detectors for use in retina neurophysiology studies

    Cunningham, W; Chichilnisky, E J; Horn, M; Litke, A M; Mathieson, K; McEwan, F A; Melone, J; O'Shea, V; Rahman, M; Smith, K M


    One area of major inter-disciplinary co-operation is between the particle physics and bio-medical communities. The type of large detector arrays and fast electronics developed in laboratories like CERN are becoming used for a wide range of medical and biological experiments. In the present work fabrication technology developed for producing semiconductor radiation detectors has been applied to produce arrays which have been used in neuro-physiological experiments on retinal tissue. We have exploited UVIII, a low molecular weight resist, that has permitted large area electron beam lithography. This allows the resolution to go below that of conventional photolithography and hence the production of densely packed similar to 500 electrode arrays with feature sizes down to below 2 mum. The neural signals from significant areas of the retina may thus be captured.

  13. Raman spectroscopy using 1550 nm (retina-safe) laser excitation.

    Brouillette, Carl; Huang, Hermes; Smith, Wayne; Farquharson, Stuart


    During the past decade, the use of portable Raman analyzers for field measurements has grown dramatically. However, most analyzers use 785 nm excitation lasers that can cause permanent eye damage. To overcome this safety concern, we have built a portable Fourier transform (FT) Raman analyzer using a 1550 nm retina-safe excitation laser and have compared its performance to our 1064 nm FT-Raman analyzer, which uses the same optical design. Raman theory predicts approximately five times lower peak intensities at 1550 nm. Although we found that intensities were as much as 20 times less intense, the analyzer is still capable of measuring spectra of sufficient quality to identify and differentiate chemicals. PMID:21513601

  14. Using Stem Cells to Model Diseases of the Outer Retina

    Camille Yvon


    Full Text Available Retinal degeneration arises from the loss of photoreceptors or retinal pigment epithelium (RPE. It is one of the leading causes of irreversible blindness worldwide with limited effective treatment options. Generation of induced pluripotent stem cell (IPSC-derived retinal cells and tissues from individuals with retinal degeneration is a rapidly evolving technology that holds a great potential for its use in disease modelling. IPSCs provide an ideal platform to investigate normal and pathological retinogenesis, but also deliver a valuable source of retinal cell types for drug screening and cell therapy. In this review, we will provide some examples of the ways in which IPSCs have been used to model diseases of the outer retina including retinitis pigmentosa (RP, Usher syndrome (USH, Leber congenital amaurosis (LCA, gyrate atrophy (GA, juvenile neuronal ceroid lipofuscinosis (NCL, Best vitelliform macular dystrophy (BVMD and age related macular degeneration (AMD.

  15. Axonal synapses utilize multiple synaptic ribbons in the mammalian retina.

    Hong-Lim Kim

    Full Text Available In the mammalian retina, bipolar cells and ganglion cells which stratify in sublamina a of the inner plexiform layer (IPL show OFF responses to light stimuli while those that stratify in sublamina b show ON responses. This functional relationship between anatomy and physiology is a key principle of retinal organization. However, there are at least three types of retinal neurons, including intrinsically photosensitive retinal ganglion cells (ipRGCs and dopaminergic amacrine cells, which violate this principle. These cell types have light-driven ON responses, but their dendrites mainly stratify in sublamina a of the IPL, the OFF sublayer. Recent anatomical studies suggested that certain ON cone bipolar cells make axonal or ectopic synapses as they descend through sublamina a, thus providing ON input to cells which stratify in the OFF sublayer. Using immunoelectron microscopy with 3-dimensional reconstruction, we have identified axonal synapses of ON cone bipolar cells in the rabbit retina. Ten calbindin ON cone bipolar axons made en passant ribbon synapses onto amacrine or ganglion dendrites in sublamina a of the IPL. Compared to the ribbon synapses made by bipolar terminals, these axonal ribbon synapses were characterized by a broad postsynaptic element that appeared as a monad and by the presence of multiple short synaptic ribbons. These findings confirm that certain ON cone bipolar cells can provide ON input to amacrine and ganglion cells whose dendrites stratify in the OFF sublayer via axonal synapses. The monadic synapse with multiple ribbons may be a diagnostic feature of the ON cone bipolar axonal synapse in sublamina a. The presence of multiple ribbons and a broad postsynaptic density suggest these structures may be very efficient synapses. We also identified axonal inputs to ipRGCs with the architecture described above.

  16. Photoreceptors in the rat retina are specifically vulnerable to both hypoxia and hyperoxia.

    Wellard, John; Lee, Donald; Valter, Krisztina; Stone, Jonathan


    The current study aims to assess the vulnerability of photoreceptors in rat retina to variations in tissue oxygen levels. Young adult Sprague-Dawley rats were exposed to air with the concentration of oxygen set at 10% (hypoxia), 21% (room air, normoxia), and four levels of hyperoxia (45%, 65%, 70%, and 75%), for up to 3 weeks. Their retinas were then examined for cell death, using the TUNEL technique. Hypoxia (10% oxygen) for 2 weeks caused a limited but significant rise in the frequency of TUNEL+ (dying) cells in the retina, the great majority (>90%) being located in the outer nuclear layer (ONL). Hyperoxia also induced an increase in the frequency of TUNEL+ cells, again predominantly in the ONL. The increase rose with duration of exposure, up to 2 weeks. At 2 weeks exposure, the increase was limited yet significant at 45% oxygen, and maximal at 65%. Where the frequencies of TUNEL+ cells were high, it was evident that photoreceptor death was maximal in the midperipheral retina. The adult retina is vulnerable to maintained shifts in oxygen availability to the retina, both below and above normal. The vulnerability is specific to photoreceptors; other retinal neurons appeared resistant to the exposures tested. Shifts in retinal oxygen levels caused by variations in ambient light, by the persistence of light through the normally dark (night) half of the day-night cycle, or by depletion of the photoreceptor population, may contribute to photoreceptor death in the normal retina. PMID:16212707

  17. First experimental-based characterization of oxygen ion beam depth dose distributions at the Heidelberg Ion-Beam Therapy Center

    Kurz, C.; Mairani, A.; Parodi, K.


    Over the last decades, the application of proton and heavy-ion beams to external beam radiotherapy has rapidly increased. Due to the favourable lateral and depth dose profile, the superposition of narrow ion pencil beams may enable a highly conformal dose delivery to the tumour, with better sparing of the surrounding healthy tissue in comparison to conventional radiation therapy with photons. To fully exploit the promised clinical advantages of ion beams, an accurate planning of the patient treatments is required. The clinical treatment planning system (TPS) at the Heidelberg Ion-Beam Therapy Center (HIT) is based on a fast performing analytical algorithm for dose calculation, relying, among others, on laterally integrated depth dose distributions (DDDs) simulated with the FLUKA Monte Carlo (MC) code. Important input parameters of these simulations need to be derived from a comparison of the simulated DDDs with measurements. In this work, the first measurements of 16O ion DDDs at HIT are presented with a focus on the determined Bragg peak positions and the understanding of factors influencing the shape of the distributions. The measurements are compared to different simulation approaches aiming to reproduce the acquired data at best. A simplified geometrical model is first used to optimize important input parameters, not known a priori, in the simulations. This method is then compared to a more realistic, but also more time-consuming simulation approach better accounting for the experimental set-up and the measuring process. The results of this work contributed to a pre-clinical oxygen ion beam database, which is currently used by a research TPS for corresponding radio-biological cell experiments. A future extension to a clinical database used by the clinical TPS at HIT is foreseen. As a side effect, the performed investigations showed that the typical water equivalent calibration approach of experimental data acquired with water column systems leads to slight

  18. Müller cells express the cannabinoid CB2 receptor in the vervet monkey retina

    Bouskila, Joseph; Javadi, Pasha; Casanova, Christian;


    presence of CB2R in the neural component of the retina. We therefore thoroughly examined the cellular localization of CB2R in the vervet monkey (Chlorocebus sabeus) retina, using confocal microscopy. Our results demonstrate that CB2R, like CB1R, is present throughout the retinal layers, but with striking...... dissimilarities. Double labeling of CB2R and glutamine synthetase shows that CB2R is restricted to Müller cell processes, extending from the internal limiting membrane, with very low staining, to the external limiting membrane, with heavy labeling. We conclude that CB2R is indeed present in the retina but...

  19. Temperature rise and tissue damage in the primate retina from argon laser irradiation

    Temperatures from argon laser irradiation were measured in vivo in Macaca mulatta retinae for exposure durations .002s to 100s with a microthermocouple probe specially designed for measuring transient tissue temperatures. Measured temperatures were compared to predicted temperatures from a mathematical model of temperature for the retina and choroid. Radiant energy levels required to produce retinal lesions were determined by both ophthalmoscopic and microscopic examination of the ocular fundus. Temperatures associated with retinal lesion formation were measured, for macular and paramacular exposures. Measured temperatures were used to improve a rate process model for predicting thermal damage to the retina

  20. Comparison of methods for quantitating Salmonella enterica Typhimurium and Heidelberg strain attachment to reusable plastic shipping container coupons and preliminary assessment of sanitizer efficacy.

    Shi, Zhaohao; Baker, Christopher A; Lee, Sang In; Park, Si Hong; Kim, Sun Ae; Ricke, Steven C


    Salmonella serovars, one of the leading contributors to foodborne illness and are especially problematic for foods that are not cooked before consumption, such as fresh produce. The shipping containers that are used to transport and store fresh produce may play a role in cross contamination and subsequent illnesses. However, methods for quantitatively attached cells are somewhat variable. The overall goal of this study was to compare conventional plating with molecular methods for quantitating attached representative strains for Salmonella Typhimurium and Heidelberg on reusable plastic containers (RPC) coupons, respectively. We attached Salmonella enterica serovar Typhimurium ATCC 14028 and serovar Heidelberg SL486 (parent and an antibiotic resistant marker strain) to plastic coupons (2.54 cm(2)) derived from previously used shipping containers by growing for 72 h in tryptic soy broth. The impact of the concentration of sanitizer on log reductions between unsanitized and sanitized coupons was evaluated by exposing attached S. Typhimurium cells to 200 ppm and 200,000 ppm sodium hypochlorite (NaClO). Differences in sanitizer effectiveness between serovars were also evaluated with attached S. Typhimurium compared to attached S. Heidelberg populations after being exposed to 200 ppm peracetic acid (PAA). Treatment with NaClO caused an average of 2.73 ± 0.23 log CFU of S. Typhimurium per coupon removed with treatment at 200 ppm while 3.36 ± 0.54 log CFU were removed at 200,000 ppm. Treatment with PAA caused an average of 2.62 ± 0.15 log CFU removed for S. Typhimurium and 1.41 ± 0.17 log CFU for S. Heidelberg (parent) and 1.61 ± 0.08 log CFU (marker). Lastly, scanning electron microscopy (SEM) was used to visualize cell attachment and coupon surface topography. SEM images showed that remaining attached cell populations were visible even after sanitizer application. Conventional plating and qPCR yielded similar levels of enumerated bacterial populations

  1. Organotypic tissue culture of adult rodent retina followed by particle-mediated acute gene transfer in vitro.

    Satoru Moritoh

    Full Text Available BACKGROUND: Organotypic tissue culture of adult rodent retina with an acute gene transfer that enables the efficient introduction of variable transgenes would greatly facilitate studies into retinas of adult rodents as animal models. However, it has been a difficult challenge to culture adult rodent retina. The purpose of this present study was to develop organotypic tissue culture of adult rodent retina followed by particle-mediated acute gene transfer in vitro. METHODOLOGY/PRINCIPAL FINDINGS: We established an interphase organotypic tissue culture for adult rat retinas (>P35 of age which was optimized from that used for adult rabbit retinas. We implemented three optimizations: a greater volume of Ames' medium (>26 mL per retina, a higher speed (constant 55 rpm of agitation by rotary shaker, and a greater concentration (10% of horse serum in the medium. We also successfully applied this method to adult mouse retina (>P35 of age. The organotypic tissue culture allowed us to keep adult rodent retina morphologically and structurally intact for at least 4 days. However, mouse retinas showed less viability after 4-day culture. Electrophysiologically, ganglion cells in cultured rat retina were able to generate action potentials, but exhibited less reliable light responses. After transfection of EGFP plasmids by particle-mediated acute gene transfer, we observed EGFP-expressing retinal ganglion cells as early as 1 day of culture. We also introduced polarized-targeting fusion proteins such as PSD95-GFP and melanopsin-EYFP (hOPN4-EYFP into rat retinal ganglion cells. These fusion proteins were successfully transferred into appropriate locations on individual retinal neurons. CONCLUSIONS/SIGNIFICANCE: This organotypic culture method is largely applicable to rat retinas, but it can be also applied to mouse retinas with a caveat regarding cell viability. This method is quite flexible for use in acute gene transfection in adult rodent retina, replacing

  2. Blood Contrast Agents Enhance Intrinsic Signals in the Retina: Evidence for an Underlying Blood Volume Component

    Schallek, Jesse; Ts'o, Daniel


    Systemic injections of blood contrast agents nigrosin and indocyanine green increased stimulus-evoked reflectance signals in the retina. The enhancement of signal strength is consistent with neurovascular coupling in response to visual stimulation.

  3. Retina-on-a-chip: a microfluidic platform for point access signaling studies.

    Dodson, Kirsten H; Echevarria, Franklin D; Li, Deyu; Sappington, Rebecca M; Edd, Jon F


    We report on a microfluidic platform for culture of whole organs or tissue slices with the capability of point access reagent delivery to probe the transport of signaling events. Whole mice retina were maintained for multiple days with negative pressure applied to tightly but gently bind the bottom of the retina to a thin poly-(dimethylsiloxane) membrane, through which twelve 100 μm diameter through-holes served as fluidic access points. Staining with toluidine blue, transport of locally applied cholera toxin beta, and transient response to lipopolysaccharide in the retina demonstrated the capability of the microfluidic platform. The point access fluidic delivery capability could enable new assays in the study of various kinds of excised tissues, including retina. PMID:26559199

  4. Adenosine as a signaling molecule in the retina: biochemical and developmental aspects



    Full Text Available The nucleoside adenosine plays an important role as a neurotransmitter or neuromodulator in the central nervous system, including the retina. In the present paper we review compelling evidence showing that adenosine is a signaling molecule in the developing retina. In the chick retina, adenosine transporters are present since early stages of development before the appearance of adenosine A1 receptors modulating dopamine-dependent adenylate cyclase activity or A2 receptors that directly activate the enzyme. Experiments using retinal cell cultures revealed that adenosine is taken up by specific cell populations that when stimulated by depolarization or neurotransmitters such as dopamine or glutamate, release the nucleoside through calcium-dependent transporter-mediated mechanisms. The presence of adenosine in the extracellular medium and the long-term activation of adenosine receptors is able to regulate the survival of retinal neurons and blocks glutamate excitoxicity. Thus, adenosine besides working as a neurotransmitter or neuromodulator in the mature retina, is considered as an important signaling molecule during retinal development having important functions such as regulation of neuronal survival and differentiation.O nucleosídeo adenosina apresenta um importante papel como neurotransmissor ou neuromodulador no sistema nervoso central, inclusive na retina. Neste artigo apresentamos uma revisão das evidências que mostram que a adenosina é uma molécula sinalizadora na retina em desenvolvimento. Na retina de pinto, transportadores de adenosina estão presentes desde estágios precoces do desenvolvimento, antes do aparecimento dos receptores A1 que modulam a atividade adenilato ciclase dependente de dopamina ou dos receptores A2 que ativam diretamente a enzima. Experimentos usando culturas de células de retina revelaram que a adenosina é captada por populações celulares específicas que, quando estimuladas por despolarização ou por

  5. Integration von Schulungsveranstaltungen der Bibliothek ins Curriculum - am Beispiel der Fakultät für Klinische Medizin Mannheim der Universität Heidelberg

    Semmler-Schmetz, Martina


    Full Text Available In the winter semester 2004/05 the Faculty for Clinical Medicine Mannheim of Heidelberg University implemented the new Querschnittsschein "Epidemiology, medical biometrics and medical informatics" and integrated the first library instructional classes into its medical curriculum. In order to meet the new requirements the medical library established an instructional team that designed tailor-made courses for the student target group and put into practice the experiences gathered both in workshops (such as the continuing education course "Teaching Library" offered by the BIB in May 2004 and from the relevant literature. With a maximum participation of library staff almost all of the first clinical semster medical students finished three different instructional modules of the beginners and intermediate skill levels. Resonance to these courses was ascertained by evaluation forms completed by the participants immediately after the classes. The feedback was predominantly positive, and the members of the instructional team unanimously regarded the experiences made as new and inspiring. As a further development of the orientation and instruction classes integrated in the curriculum the medical library intends to participate in the navigation system LOTSE of the Universitäts- und Landesbibliothek Münster starting in the academic year 2005/06. Moreover, by then, one of the aforementioned classes is planned to be offered on the e-Learning platform ATHENA of Heidelberg University.

  6. Studio caso-controllo multicentrico su distacco di retina e movimentazione manuale di carichi

    Zanardi, Francesca


    Obiettivo Valutare l’ipotesi secondo cui la movimentazione manuale di carichi possa essere un fattore di rischio per il di distacco di retina. Metodi Si è condotto uno studio caso-controllo ospedaliero multicentrico, a Bologna, (reparto di Oculistica del policlinico S. Orsola Malpighi, Prof. Campos), e a Brescia (reparto di oculistica “Spedali Civili” Prof. Semeraro). I casi sono 104 pazienti operati per distacco di retina. I controlli sono 173 pazienti reclutati tra l’utenza degli ambulatori...

  7. Evaluation of the percentage of ganglion cells in the ganglion cell layer of the rodent retina

    Schlamp, Cassandra L.; Montgomery, Angela D.; Mac Nair, Caitlin E.; Schuart, Claudia; Willmer, Daniel J.; Nickells, Robert W


    Purpose Retinal ganglion cells comprise a percentage of the neurons actually residing in the ganglion cell layer (GCL) of the rodent retina. This estimate is useful to extrapolate ganglion cell loss in models of optic nerve disease, but the values reported in the literature are highly variable depending on the methods used to obtain them. Methods We tested three retrograde labeling methods and two immunostaining methods to calculate ganglion cell number in the mouse retina (C57BL/6). Addition...

  8. Evolutionary transformation of rod photoreceptors in the all-cone retina of a diurnal garter snake

    Ryan K Schott; Müller, Johannes; Yang, Clement G. Y.; Bhattacharyya, Nihar; Chan, Natalie; Xu, Mengshu; Morrow, James M.; Ghenu, Ana-Hermina; Loew, Ellis R.; Tropepe, Vincent; Chang, Belinda S W


    This study provides compelling evidence that the previously reported all-cone retina of a diurnal garter snake in fact contains a population of rod photoreceptors with the appearance, and presumably function, of cones. Our results suggest that the evolution of all-cone retinas occurred not through loss of rods but rather via the evolutionary transmutation of ancestral rods into more “cone-like” photoreceptors, to regain functionality that was lost during the early, possibly fossorial, origin ...

  9. A Study of Histology and Enzymatic Histochemistry on Rabbit's Retina in Acute Ocular Hypertension


    The changes of activities of enzymes relating to energy metabolism in rabbit's retina in acute ocular hypertension were observed. The activities of succinate dehydrogenase and adenosine triphosphatase were found to be reduced, while the activities of the lactatic dehydrognease and glucose-6-phosphatase increased. The results revealed the metabolic disturbance of energy in retina after acute ocular hypertension might be the underlying factors relating to the defects of the functions and structures of the...

  10. Non-viral siRNA delivery into the mouse retina in vivo

    Zoidl Georg


    Full Text Available Abstract Background Gene silencing in the retina using RNA interference could open broad possibilities for functional studies of genes in vivo and for therapeutic interventions in eye disorders. Therefore, there is a considerable demand for protocols to deliver siRNA into the vertebrate retina. In this work we explored a possibility to deliver synthetic 21 bp siRNA into the mouse retina after intravitreal application using a non-viral carrier. Methods Fluorescently labelled synthetic 21 bp siRNA duplex was combined with Transit-TKO transfection reagent and injected intravitreally into adult mice eyes. Eyes cryostat sections and whole mount retinas were prepared 24-48 h post-injection, stained with either Hoechst 33342 (cell nuclei or immunostained with anti-GFAP antibody (astroglia cells marker. Distribution of fluorescent siRNA signal in the retina was investigated. Results Single intravitreal injection of as little as 5 ng of siRNA combined with Transit-TKO transfection reagent by a modified protocol provided robust and non-toxic delivery of the siRNA into the retina. However, siRNA accumulation was predominantly confined to ganglion cells layer as analysed 24 h post-injection. Furthermore, siRNA containing particles were localized along GFAP cytoskeleton of retinal astroglial cells hinting on intracellular localization of the siRNA Conclusions In this work we demonstrated that siRNA can be efficiently delivered into the vertebrate retina in vivo with low-toxicity using a non-viral carrier, specifically Transit-TKO transfection reagent. However, the capacity of siRNA delivered by our protocol to induce gene silencing in the retina has to be further evaluated. Our report could raise a closer look on Transit-TKO transfection reagent as a promising siRNA carrier in vivo and be of interest for the researchers and companies who work on development of ocular RNAi techniques.

  11. Vascular and avascular retinae in mammals. A funduscopic and fluorescein angiographic study.

    Buttery, R G; Haight, J R; Bell, K


    Intraretinal blood vessels are present in some and absent in other vertebrate species, including the mammals. Among the marsupials, both vascular and avascular retinae are seen. We determined the funduscopic appearance of the eye, investigated the functional aspects of ocular blood flow in both types of retina in marsupials and compared our results with known patterns in placental mammals. The Australian polyprotodont marsupials, the Tasmanian devil, Sarcophilus harrisii, and the quoll, Dasyurus viverrinus, together with an American polyprotodont, the Virginia opossum, Didelphis virginiana, demonstrate variable degrees of tapetal differentiation, pigmentation and a very close parallel course of their intraretinal arteries and veins over considerable distances. Using the technique of fluorescein angiography, we found that retinal blood flow in the 3 vascular Australian species commenced with arterial filling. Early venous was seen next, followed by the capillary blush. This unusual sequence of vascular flow differs from that of the arterial-capillary-venous filling seen in placental mammals. This difference is most likely a consequence of the known looped, end artery organisation found within marsupial nervous systems, of which the retinae are a part. The 2 diprotodont marsupials examined, the brushtail possum, Trichosurus vulpecula, and the sugar glider, Petaurus breviceps, possess avascular retinae. Only a small residual tuft of fluorescein-impermeable vessels projects from the optic disc into the vitreous. Interestingly, the structural complexity of the central visual system in diprotodonts all of whom possess avascular retinae) is commonly accepted as being greater than that of the stem polyprotodont line (which possess vascular retinae). If retinal function matches this internal complexity, then retinal avascularity may, as in birds, be associated with superior vision. However, as the retinae of these mammals clearly lack any nutritive mechanisms directly

  12. Retinoic acid is necessary for development of the ventral retina in zebrafish.

    Marsh-Armstrong, N; McCaffery, P; Gilbert, W; Dowling, J E; Dräger, U C


    In the embryonic zebrafish retina, as in other vertebrates, retinoic acid is synthesized from retinaldehyde by two different dehydrogenases, one localized dorsally, the other primarily ventrally. Early in eye development only the ventral enzyme is present. Citral competitively inhibits the ventral enzyme in vitro and decreases the production of retinoic acid in the ventral retina in vivo. Treatment of neurula-stage zebrafish embryos with citral during the formation of the eye primordia result...

  13. The lens controls cell survival in the retina: evidence from the blind cavefish Astyanax

    STRICKLER, Allen G.; Yamamoto, Yoshiyuki; Jeffery, William R.


    The lens influences retinal growth and differentiation during vertebrate eye development but the mechanisms are not understood. The role of the lens in retinal growth and development was studied in the teleost Astyanax mexicanus, which has eyed surface-dwelling (surface fish) and blind cave-dwelling (cavefish) forms. A lens and laminated retina initially develop in cavefish embryos, but the lens dies by apoptosis. The cavefish retina is subsequently disorganized, apoptotic cells appear, the p...

  14. Otx2 Gene Deletion in Adult Mouse Retina Induces Rapid RPE Dystrophy and Slow Photoreceptor Degeneration

    Francis Béby; Michael Housset; Nicolas Fossat; Coralie Le Greneur; Frédéric Flamant; Pierre Godement; Thomas Lamonerie


    Background : Many developmental genes are still active in specific tissues after development is completed. This is the case for the homeobox gene Otx2, an essential actor of forebrain and head development. In adult mouse, Otx2 is strongly expressed in the retina. Mutations of this gene in humans have been linked to severe ocular malformation and retinal diseases. It is, therefore, important to explore its post-developmental functions. In the mature retina, Otx2 is expressed in three cell type...

  15. Neurochemical phenotype and birthdating of specific cell populations in the chick retina

    Karin da Costa calaza; Patricia F. Gardino


    The chick embryo is one of the most traditional models in developing neuroscience and its visual system has been one of the most exhaustively studied. The retina has been used as a model for studying the development of the nervous system. Here, we describe the morphological features that characterize each stage of the retina development and studies of the neurogenesis period of some specific neurochemical subpopulations of retinal cells by using a combination of immunohistochemistry and autor...

  16. Distribution of [35S] taurine in mouse retina after intravitreal and intravascular injection

    The distribution of [35S] taurine in mouse retinae was studied by autoradiographic techniques after either intravitreal or intravascular injection. The route of injection did not affect the final localization. The major sites of label accumulation were the outer nuclear layer, the inner nuclear layer, and Mueller cell processes adjacent to the vitreal surface. The distribution was consistent with the interpretation that taurine was localized within two cellular compartments of mouse retina, photoreceptor cells and Mueller cells. (author)

  17. An alternative pathway for signal flow from rod photoreceptors to ganglion cells in mammalian retina.

    DeVries, S H; Baylor, D A


    Rod signals in the mammalian retina are thought to reach ganglion cells over the circuit rod-->rod depolarizing bipolar cell-->AII amacrine cell-->cone bipolar cells-->ganglion cells. A possible alternative pathway involves gap junctions linking the rods and cones, the circuit being rod-->cone-->cone bipolar cells-->ganglion cells. It is not clear whether this second pathway indeed relays rod signals to ganglion cells. We studied signal flow in the isolated rabbit retina with a multielectrode...

  18. Rax: Developmental and Daily Expression Patterns in the Rat Pineal Gland and Retina

    Rohde, Kristian; Klein, David C.; Møller, Morten; Rath, Martin F.


    Retina and anterior neural fold homeobox (Rax) gene encodes a transcription factor essential for vertebrate eye development. Recent microarray studies indicate that Rax is expressed in the adult rat pineal gland and retina. The present study reveals that Rax expression levels in the rat change significantly during retinal development with a peak occurring at embryonic day (E) 18, whereas Rax expression in the pineal is relatively delayed and not detectable until E20. In both tissues, Rax is e...

  19. Extraction of arteries and veins from fundus image of human retina.

    Pinkava, Marek


    This thesis deals with processing of retinal fundus images. Vision is the most important human sense and its injury has very serious consequences for humans. Automatic processing of retinal images increases the efficiency of medical examination and accelerates diagnoses of deseases. Retina exhibits unique characteristics for each person and thus can also be used to identify people. In this task is briefly discussed the structure and properties of each parts of the eye, particularly the retina...

  20. von Hippel-Lindau protein regulates transition from fetal to adult circulatory system in retina

    Kurihara, Toshihide; Kubota, Yoshiaki; Ozawa, Yoko; Takubo, Keiyo; Noda, Kousuke; Simon, M. Celeste; Johnson, Randall S; Suematsu, Makoto; Tsubota, Kazuo; Ishida, Susumu; Goda, Nobuhito; Suda, Toshio; Okano, Hideyuki


    In the early neonatal stage, the fetal circulatory system undergoes dramatic transition to the adult circulatory system. Normally, embryonic connecting vessels such as ductus arteriosus and the foramen ovale close and regress. In the neonatal retina, hyaloid vessels maintaining blood flow in the embryonic retina regress, and retinal vessels take over to form adult-type circulatory system. This process is regulated by the programmed cell death switch mediated by macrophages via Wnt and Angiopo...

  1. Optimal Prediction in the Retina and Natural Motion Statistics

    Salisbury, Jared M.; Palmer, Stephanie E.


    Almost all behaviors involve making predictions. Whether an organism is trying to catch prey, avoid predators, or simply move through a complex environment, the organism uses the data it collects through its senses to guide its actions by extracting from these data information about the future state of the world. A key aspect of the prediction problem is that not all features of the past sensory input have predictive power, and representing all features of the external sensory world is prohibitively costly both due to space and metabolic constraints. This leads to the hypothesis that neural systems are optimized for prediction. Here we describe theoretical and computational efforts to define and quantify the efficient representation of the predictive information by the brain. Another important feature of the prediction problem is that the physics of the world is diverse enough to contain a wide range of possible statistical ensembles, yet not all inputs are probable. Thus, the brain might not be a generalized predictive machine; it might have evolved to specifically solve the prediction problems most common in the natural environment. This paper summarizes recent results on predictive coding and optimal predictive information in the retina and suggests approaches for quantifying prediction in response to natural motion. Basic statistics of natural movies reveal that general patterns of spatiotemporal correlation are present across a wide range of scenes, though individual differences in motion type may be important for optimal processing of motion in a given ecological niche.

  2. Mouse embryonic retina delivers information controlling cortical neurogenesis.

    Ciro Bonetti

    Full Text Available The relative contribution of extrinsic and intrinsic mechanisms to cortical development is an intensely debated issue and an outstanding question in neurobiology. Currently, the emerging view is that interplay between intrinsic genetic mechanisms and extrinsic information shape different stages of cortical development. Yet, whereas the intrinsic program of early neocortical developmental events has been at least in part decoded, the exact nature and impact of extrinsic signaling are still elusive and controversial. We found that in the mouse developing visual system, acute pharmacological inhibition of spontaneous retinal activity (retinal waves-RWs during embryonic stages increase the rate of corticogenesis (cell cycle withdrawal. Furthermore, early perturbation of retinal spontaneous activity leads to changes of cortical layer structure at a later time point. These data suggest that mouse embryonic retina delivers long-distance information capable of modulating cell genesis in the developing visual cortex and that spontaneous activity is the candidate long-distance acting extrinsic cue mediating this process. In addition, these data may support spontaneous activity to be a general signal coordinating neurogenesis in other developing sensory pathways or areas of the central nervous system.

  3. The Analysis of Artificial Retina Organization for Signal Processing

    WEI Hui


    Machine vision is an active branch of artificial intelligence. An important problem in this area is the trade-off among efficiency, accuracy and computation complexity. The human visual system can keep watchfulness to the perimeter of a viewing field while at the same time focus on the center of the field for fine information processing. This mechanism of appropriate assignment of computing resources can reduce the demand for huge and complex hardware structure. Therefore, the design of a computer model based on the biological visual mechanism is an effective approach to resolve problems in machine vision. In this paper, a multi-layer neural model is developed based on the features of receptive field of ganglion in retina to simulate multi-scale perceptive fields of ganglion cell. The neural model can maintain alert on the outer area of the image while capturing and processing more important information in the central part. It may provide valuable inspiration for the implementation of real-time processing and avoidance of huge computation in machine vision.

  4. Microcystic macular edema detection in retina OCT images

    Swingle, Emily K.; Lang, Andrew; Carass, Aaron; Ying, Howard S.; Calabresi, Peter A.; Prince, Jerry L.


    Optical coherence tomography (OCT) is a powerful imaging tool that is particularly useful for exploring retinal abnormalities in ophthalmological diseases. Recently, it has been used to track changes in the eye associated with neurological diseases such as multiple sclerosis (MS) where certain tissue layer thicknesses have been associated with disease progression. A small percentage of MS patients also exhibit what has been called microcystic macular edema (MME), where uid collections that are thought to be pseudocysts appear in the inner nuclear layer. Very little is known about the cause of this condition so it is important to be able to identify precisely where these pseudocysts occur within the retina. This identi cation would be an important rst step towards furthering our understanding. In this work, we present a detection algorithm to nd these pseudocysts and to report on their spatial distribution. Our approach uses a random forest classi er trained on manual segmentation data to classify each voxel as pseudocyst or not. Despite having a small sample size of ve subjects, the algorithm correctly identi es 84.6% of pseudocysts as compared to manual delineation. Finally, using our method, we show that the spatial distribution of pseudocysts within the macula are generally contained within an annulus around the fovea.

  5. High resolution confocal polarimeter for the living human retina

    Lara, D.; Paterson, C.


    There is strong evidence that the living human retina has polarization signatures that could be linked to the presence of Glaucoma, an ocular disease that is the second cause of blindness in the western world. In a polarization sensitive ophthalmoscope, the amount of light that can be used is limited for the safety of the subject, and the return is typically a small fraction of the light used for illumination, of the order of 10-6. Furthermore, the acquisition rates have to be sufficiently fast to avoid eye-movement artifacts. The light-budget available to produce a polarization image with a scanning laser ophthalmoscope is typically in the order of 10 nW, and pixel acquisition sampling rates are of several MHz. We are currently developing an imaging instrument for vision research and clinical vision applications and aim to introduce it to the medical and clinical environment using objective methods of image quality assessment. Here we discuss the stringent imaging requirements, polarimeter design, and show high resolution polarization retinal images.

  6. A Comparative Analysis of the Endocannabinoid System in the Retina of Mice, Tree Shrews, and Monkeys

    Bouskila, Joseph; Javadi, Pasha; Elkrief, Laurent; Casanova, Christian; Bouchard, Jean-François; Ptito, Maurice


    The endocannabinoid (eCB) system is widely expressed in various parts of the central nervous system, including the retina. The localization of the key eCB receptors, particularly CB1R and CB2R, has been recently reported in rodent and primate retinas with striking interspecies differences. Little is known about the distribution of the enzymes involved in the synthesis and degradation of these eCBs. We therefore examined the expression and localization of the main components of the eCB system in the retina of mice, tree shrews, and monkeys. We found that CB1R and FAAH distributions are well-preserved among these species. However, expression of NAPE-PLD is circumscribed to the photoreceptor layer only in monkeys. In contrast, CB2R expression is variable across these species; in mice, CB2R is found in retinal neurons but not in glial cells; in tree shrews, CB2R is expressed in Müller cell processes of the outer retina and in retinal neurons of the inner retina; in monkeys, CB2R is restricted to Müller cells. Finally, the expression patterns of MAGL and DAGLα are differently expressed across species. Overall, these results provide evidence that the eCB system is differently expressed in the retina of these mammals and suggest a distinctive role of eCBs in visual processing. PMID:26977322

  7. Streaming an image through the eye: The retina seen as a dithered scalable image coder

    Masmoudi, Khaled; Kornprobst, Pierre


    We propose the design of an original scalable image coder/decoder that is inspired from the mammalians retina. Our coder accounts for the time-dependent and also nondeterministic behavior of the actual retina. The present work brings two main contributions: As a first step, (i) we design a deterministic image coder mimicking most of the retinal processing stages and then (ii) we introduce a retinal noise in the coding process, that we model here as a dither signal, to gain interesting perceptual features. Regarding our first contribution, our main source of inspiration will be the biologically plausible model of the retina called Virtual Retina. The main novelty of this coder is to show that the time-dependent behavior of the retina cells could ensure, in an implicit way, scalability and bit allocation. Regarding our second contribution, we reconsider the inner layers of the retina. We emit a possible interpretation for the non-determinism observed by neurophysiologists in their output. For this sake, we mode...

  8. Hazardous effects of fried potato chips on the development of retina in albino rats

    Hassan I El-Sayyad; Saber A Sakr; Gamal M Badawy; Hanaa S Afify


    Objective: To evaluate the hazardous effects of fried potato chips upon the retina of two developmental stages of the albino rats aged 7 and 14 days from parturition. Methods: Pregnant rats were arranged into two groups: control pregnant rats and consequently their delivered newborns until reaching 7 and 14 days old from parturition and fried potato chips group in which pregnant rats at the 6th day of gestation maintained on diet formed of fried potato chips supplied from the market mixed with standard diet at a concentration of 50% per each till 7 and 14 post-partum. Three fold integrated approaches were adopted, namely, histological, ultrastructural and proteomic analysis. Results: Histological examination of the retina of the experimental offsprings revealed many histopathological changes, including massive degeneration, vacuolization and cell loss in the ganglion cell layer, as well as general reduction in retinal size. At the ultrastructural level, the retina of experimental offsprings exhibited number of deformities, including ill differentiated and degenerated nuclear layer, malformed and vacuolated pigment epithelium with vesiculated and fragmented rough endoplasmic reticulum, degenerated outer segment of photoreceptors, as well as swollen choriocapillaris and loss of neuronal cells. Proteomic analysis of retina of the two experimental developmental stages showed variations in the expressed proteins as a result of intoxication which illustrated the adverse toxic effects of fried potato chips upon the retina. Conclusions: It can be concluded that the effect of fried potato chips on the development of retina in rats may be due to the presence of acrylamide or its metabolite.

  9. Spatiotemporal features of early neuronogenesis differ in wild-type and albino mouse retina

    Rachel, Rivka A.; Dolen, Gul; Hayes, Nancy L.; Lu, Alice; Erskine, Lynda; Nowakowski, Richard S.; Mason, Carol A.


    In albino mammals, lack of pigment in the retinal pigment epithelium is associated with retinal defects, including poor visual acuity from a photoreceptor deficit in the central retina and poor depth perception from a decrease in ipsilaterally projecting retinal fibers. Possible contributors to these abnormalities are reported delays in neuronogenesis (Ilia and Jeffery, 1996) and retinal maturation (Webster and Rowe, 1991). To further determine possible perturbations in neuronogenesis and/or differentiation, we used cell-specific markers and refined birth dating methods to examine these events during retinal ganglion cell (RGC) genesis in albino and pigmented mice from embryonic day 11 (E11) to E18. Our data indicate that relative to pigmented mice, more ganglion cells are born in the early stages of neuronogenesis in the albino retina, although the initiation of RGC genesis in the albino is unchanged. The cellular organization of the albino retina is perturbed as early as E12. In addition, cell cycle kinetics and output along the nasotemporal axis differ in retinas of albino and pigmented mice, both absolutely, with the temporal aspect of the retina expanded in albino, and relative to the position of the optic nerve head. Finally, blocking melanin synthesis in pigmented eyecups in culture leads to an increase in RGC differentiation, consistent with a role for melanin formation in regulating RGC neuronogenesis. These results point to spatiotemporal defects in neuronal production in the albino retina, which could perturb expression of genes that specify cell fate, number, and/or projection phenotype.

  10. Blood supply to the retina and the lens in the gerbil (Meriones unguiculatus).

    Imada, Hideki; Isomura, Genzoh; Miyachi, Ei-ichi


    The blood supply to the retina and the lens in 32 gerbils (Meriones unguiculatus) of both sexes from infancy to maturity was studied under light and stereoscopic microscopes, and a scanning electron microscope. Mercox (CL-2R; Dai Nippon Ink, Tokyo, Japan) was injected into the left ventricle of 30 animals in order to visualize the blood supply to the retina and the lens from the ophthalmic artery. The central retinal artery arises from the ophthalmic artery, passes through the papilla of the optic nerve together with the central retinal vein and penetrates the vitreous space (cavity of the eye) between the lens and the internal limiting membrane of the retina, where it divides into the central branches covering the lens and the parietal branches to supply the retina. The former passes through the hyaloid space after branching several arterioles and then covers the lens like a network from its medial and marginal sides. Different from small experimental animals, the parietal branches, just after separating from the central one, divides into the nasal, dorsal and temporal branches in the vitreous space, each of which then subdivides to distribute across the retina on the inner limiting membrane, then delineates the membrana vasculosa retinae. This basal pattern of vasculization 1 day after birth continues to death. Both the central and parietal branches of the central retinal artery correspond to the branches of the hyaloid artery in embryo and the latter is preserved in adult gerbils. PMID:12680468

  11. Gradual and partial loss of corner cone-occupied area in the retina of rainbow trout.

    Flamarique, I N


    Several studies have indicated that the rainbow trout (Oncorhynchus mykiss) loses ultraviolet (UV) sensitivity and the associated UV-sensitive corner cones when the animal transforms from a small (parr) juvenile to a larger, silver-coloured, smolt. Similar changes supposedly take place when parr juveniles are treated with thyroid hormone (T(4)) or retinoic acid. In contrast to previous investigations, this study shows that parr juveniles lack corner cones throughout the lower half of the ventral retina, suggesting that corner cones cease to be incorporated into the ventral retina some time after hatching. This uneven incorporation of corner cones across the retina, when combined with retinal growth, creates a progressively smaller area of lower retina occupied by corner cones. Because in previous studies, the stimulating illumination was directed primarily at the ventral retina, the reported age-dependent changes in UV or polarization sensitivities can be explained by differences in the area of corner cones that was illuminated, and not necessarily by a loss of corner cones. This study also shows: (1) that the double cones from non-ventral mosaics of parr rainbow trout may change in cross-sectional shape, altering the mosaic formation from a square to a row, (2) the existence of a 'pure' (non-changing) square mosaic in the ventral retina, and (3) a potential method, based on differential staining of cone nuclei, to classify paired cones into double or twin cones. PMID:11711133

  12. Crizotinib-Induced Abnormal Signal Processing in the Retina

    Ishii, Toshiyuki; Iwasawa, Shunichiro; Kurimoto, Ryota; Maeda, Akemi; Takiguchi, Yuichi; Kaneda, Makoto


    Molecular target therapy for cancer is characterized by unique adverse effects that are not usually observed with cytotoxic chemotherapy. For example, the anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitor crizotinib causes characteristic visual disturbances, whereas such effects are rare when another ALK-tyrosine kinase inhibitor, alectinib, is used. To elucidate the mechanism responsible for these visual disturbances, the responses to light exhibited by retinal ganglion cells treated with these agents were evaluated using a C57BL6 mouse ex vivo model. Both crizotinib and alectinib changed the firing rate of ON and OFF type retinal ganglion cells. However, the ratio of alectinib-affected cells (15.7%) was significantly lower than that of crizotinib-affected cells (38.6%). Furthermore, these drugs changed the response properties to light stimuli of retinal ganglion cells in some of the affected cells, i.e., OFF cells responded to both ON and OFF stimuli, etc. Finally, the expressions of ALK (a target receptor of both crizotinib and alectinib) and of MET and ROS1 (additional target receptors of crizotinib) were observed at the mRNA level in the retina. Our findings suggest that these drugs might target retinal ganglion cells and that the potency of the drug actions on the light responses of retinal ganglion cells might be responsible for the difference in the frequencies of visual disturbances observed between patients treated with crizotinib and those treated with alectinib. The present experimental system might be useful for screening new molecular target agents prior to their use in clinical trials. PMID:26271036

  13. Adenovirus vectors targeting distinct cell types in the retina.

    Sweigard, J Harry; Cashman, Siobhan M; Kumar-Singh, Rajendra


    Purpose. Gene therapy for a number of retinal diseases necessitates efficient transduction of photoreceptor cells. Whereas adenovirus (Ad) serotype 5 (Ad5) does not transduce photoreceptors efficiently, previous studies have demonstrated improved photoreceptor transduction by Ad5 pseudotyped with Ad35 (Ad5/F35) or Ad37 (Ad5/F37) fiber or by the deletion of the RGD domain in the Ad5 penton base (Ad5DeltaRGD). However, each of these constructs contained a different transgene cassette, preventing the evaluation of the relative performance of these vectors, an important consideration before the use of these vectors in the clinic. The aim of this study was to evaluate these vectors in the retina and to attempt photoreceptor-specific transgene expression. Methods. Three Ad5-based vectors containing the same expression cassette were generated and injected into the subretinal space of adult mice. Eyes were analyzed for green fluorescence protein expression in flat-mounts, cross-sections, quantitative RT-PCR, and a modified stereological technique. A 257-bp fragment derived from the mouse opsin promoter was analyzed in the context of photoreceptor-specific transgene expression. Results. Each virus tested efficiently transduced the retinal pigment epithelium. The authors found no evidence that Ad5/F35 or Ad5/F37 transduced photoreceptors. Instead, they found that Ad5/F37 transduced Müller cells. Robust photoreceptor transduction by Ad5DeltaRGD was detected. Photoreceptor-specific transgene expression from the 257-bp mouse opsin promoter in the context of Ad5DeltaRGD vectors was found. Conclusions. Adenovirus vectors may be designed with tropism to distinct cell populations. Robust photoreceptor-specific transgene expression can be achieved in the context of Ad5DeltaRGD vectors. PMID:19892875

  14. Effect of ozone therapy on cell apoptosis and angiogenesis in retina tissue of diabetic retinopathy rats

    Xiao Liu


    ABSTRACT Objective:To study the effect of ozone therapy on cell apoptosis and angiogenesis in retina tissue of diabetic retinopathy rats.Methods:SD rats were selected as experimental animals and divided into control group, model group and ozone group, and after diabetic models were built, ozone enema was conducted. Retina tissue was collected, TUNEL kits were used to detect the number of apoptotic cells, and Elisa kits were used to detect the contents of nerve damage molecules, angiogenesis-related molecules and endoplasmic reticulum stress molecules. Results:The number of apoptotic cells in retina tissue of model group was significantly more than that of control group, and the number of apoptotic cells in retina tissue of ozone group was significantly less than that of model group; NgR, NR2B, ERK1, ERK2, GFAP, VEGF, STAT-3, HIF-1α, Apelin, APJ, PERK, IRE-1α, ATF-6, eIF2α and XBP-1 contents in retina tissue of model group were significantly higher than those of control group, and PEDF content was lower than that of control group; NgR, NR2B, ERK1, ERK2, GFAP, VEGF, STAT-3, HIF-1α, Apelin, APJ, PERK, IRE-1α, ATF-6, eIF2α and XBP-1 contents in retina tissue of ozone group were significantly lower than those of model group, and PEDF content was higher than that of model group.Conclusion:Ozone therapy can reduce the number of apoptotic cells while reduce nerve cell injury and inhibit angiogenesis and endoplasmic reticulum stress in retina tissue of diabetic rats.

  15. Atrofia girata de coróide e retina: relato de caso Girate atrophy of the retina and choroid: case report

    Emerson Kenji Oyamaguchi


    Full Text Available OBJETIVO: Relatar um caso de atrofia girata de coróide e retina com confirmação por meio da bioquímica do plasma. MÉTODO: Aferiu-se a melhor acuidade visual corrigida de ambos olhos (AO em tabela de Snellen. Foram realizados biomicroscopia do segmento anterior, refração, mapeamento de retina, angiografia fluoresceínica, campo visual e dosagem da ornitina sérica (aminoacidograma. RESULTADOS: Paciente de 22 anos, sexo feminino, cor branca, apresentando alta miopia e acuidade visual (AV 20/100 em AO. À biomicroscopia do segmento anterior apresentava catarata subcapsular posterior em AO. À oftalmoscopia foram verificadas lesões atróficas da coróide e da retina bem delimitadas em meia periferia de AO. O aminoacidograma constatou elevação correspondente ao complexo da ornitina. CONCLUSÃO: Relata-se um caso típico de atrofia girata, distrofia retiniana rara associada a hiperornitinemia.PURPOSE: To report a case of gyrate atrophy confirmed by biochemical blood analysis. METHODS: Best corrected visual acuity was evaluated. Biomicroscopy of the anterior segment, indirect ophthalmoscopy, fluorescein angiography and computerized visual fields were performed. Color vision was assessed and plasma ornithine level was determined. RESULTS: 22-year-old white female with high myopia, visual acuity of 20/100 in both eyes. Biomicroscopy showed posterior subcapsular cataract in both eyes. Retinography showed well-delineated atrophic lesions of the choroid and retina in the mid-periphery and around the optic nerve in both eyes. Blood aminoacid determination showed high levels of ornithine. CONCLUSION: We describe here a typical case of girate atrophy of the retina and choroid, a rare disease associated with high levels of plasma ornithine.

  16. Hepcidin expression in mouse retina and its regulation via lipopolysaccharide/Toll-like receptor-4 pathway independent of Hfe

    Gnana-Prakasam, Jaya P.; Martin, Pamela M.; Barbara A Mysona; Roon, Penny; Smith, Sylvia B.; Ganapathy, Vadivel


    Hepcidin is a hormone central to the regulation of iron homeostasis in the body. It is believed to be produced exclusively by the liver. Ferroportin, an iron exporter, is the receptor for hepcidin. This transporter/receptor is expressed in Müller cells, photoreceptor cells, and retinal pigment epithelium (RPE) within the retina. Since the retina is protected by the retinal-blood barriers, we asked whether ferroportin in the retina is regulated by hepcidin in the circulation or whether the ret...

  17. Effect of dietary fatty acid intake on prospective weight change in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition

    Nimptsch, Katharina; Berg-Beckhoff, Gabi; Linseisen, Jakob


    . RESULTS: Stearic acid intake was linearly associated with weight gain (P <0.01) in men and women. Linear associations also existed for ALA and arachidonic acid intake, significantly so in women. In multinomial models, women in the highest tertile of ALA and stearic acid intake showed increased OR (95 % CI......OBJECTIVE: To evaluate the association between fatty acid (alpha-linolenic acid (ALA), EPA, DHA, palmitic, stearic, oleic, linoleic and arachidonic acids) intake and prospective weight change in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition. DESIGN...... categorised into four groups (weight loss, or =2.5 to or =7.5%/5 years). Energy-adjusted dietary fatty acid intake data were estimated from the FFQ completed at baseline. Multivariate linear regression models as well as multinomial logistic regression analyses (carbohydrate replacement models) were conducted...



    Objective To study the effect of fundus pigment on the response of the retina to transpupillary thermotherapy (TTT). Methods The retina were irradiated with 810 nm diode laser in 16 eyes of 8 pigmented rabbits and 12 eyes of 6 albino rabbits. The spot size was 1.2 mm; the duration was 60 s; and powers were 50, 80, 150 and 300 mW for pigmented rabbits and 800, 1 200 and 1 500mW for albino rabbits. All of the eyes were followed up with ophthalmolscope. The fundus was photographed and examined histologically with optic microscope immediately and 1 month after TTT respectively. Results The changes of the fundus and the histological examination were not significant immediately and 1 month after TTT in 50 mW group of pigmented rabbit and 800 mW of albino rabbit. Grey spot on the retina was observed on the fundus in 80 mW group of pigmented rabbit and 1 200 mW of albino rabbit immediately after TTT. The structure of the retina remained intact and subretinal fluid was observed histologically. Grey spot was still visible on the fundus, though the fluid was absorbed after 1 month. As the power of diode laser was increased to 150 mW for pigmented rabbits and 1500 mW for albino rabbit, fundus white spots were observed and the outer retina was destroyed while photoreceptors existed immediately after TTT. Pigmentation was found in white lesions and the fibrous proliferation was found in choroid 1 month after TTT. Prominent white spot was seen on the fundus immediately after laser irradiation of 300 mW in pigmented rabbits and the structure of the retina was obscured. One month after TTT, dense pigmentation appeared at laser lesions. The retina was thinner. There was prominent fibrous proliferation in the choroid. Conclusion The fundus pigment seems to play an important role in the response of the retina to TTT. The reaction of the retina is in proportion to the intensity of laser.

  19. Retinal degeneration progression changes lentiviral vector cell targeting in the retina.

    Maritza Calame

    Full Text Available In normal mice, the lentiviral vector (LV is very efficient to target the RPE cells, but transduces retinal neurons well only during development. In the present study, the tropism of LV has been investigated in the degenerating retina of mice, knowing that the retina structure changes during degeneration. We postulated that the viral transduction would be increased by the alteration of the outer limiting membrane (OLM. Two different LV pseudotypes were tested using the VSVG and the Mokola envelopes, as well as two animal models of retinal degeneration: light-damaged Balb-C and Rhodopsin knockout (Rho-/- mice. After light damage, the OLM is altered and no significant increase of the number of transduced photoreceptors can be obtained with a LV-VSVG-Rhop-GFP vector. In the Rho-/- mice, an alteration of the OLM was also observed, but the possibility of transducing photoreceptors was decreased, probably by ongoing gliosis. The use of a ubiquitous promoter allows better photoreceptor transduction, suggesting that photoreceptor-specific promoter activity changes during late stages of photoreceptor degeneration. However, the number of targeted photoreceptors remains low. In contrast, LV pseudotyped with the Mokola envelope allows a wide dispersion of the vector into the retina (corresponding to the injection bleb with preferential targeting of Müller cells, a situation which does not occur in the wild-type retina. Mokola-pseudotyped lentiviral vectors may serve to engineer these glial cells to deliver secreted therapeutic factors to a diseased area of the retina.

  20. Expression of hermes gene is restricted to the ganglion cells in the retina.

    Piri, Natik; Kwong, Jacky M K; Song, Min; Caprioli, Joseph


    The RNA binding protein with multiple splicing 2, or hermes, is a member of the RRM (RNA recognition motif) family of RNA-binding proteins. In this study, we show that the hermes gene is expressed in the rat retina, and its expression is restricted to the ganglion cell layer. Double in situ hybridization with riboprobes corresponding to the hermes gene and Thy-1, the RGC marker in the retina, showed that the majority of the Thy-1 positive cells in the ganglion cell layer were also hermes positive. This was also shown by co-localization of the hermes in situ hybridization signals with the retrogradely labeled RGCs. Our observations suggest that hermes is expressed in the majority, if not all, of RGCs and is not restricted to only certain RGC types. Hermes in situ hybridization signals were not detected in the retinal sections of optic nerve transected animals, which are characterized by rapid and specific RGC degeneration. The dramatic reduction of the hermes mRNA level in axotomized retinas was also observed by semi-quantitative RT-PCR. The specific expression of hermes in retinal ganglion cells qualifies this gene as a potential RGC marker in the retina. Outside the retina, hermes is expressed in the heart, liver, and kidney, and to a lesser degree in the cerebellum, cortex, lung, and small intestine. PMID:16870336

  1. Mathematical and computational models of the retina in health, development and disease.

    Roberts, Paul A; Gaffney, Eamonn A; Luthert, Philip J; Foss, Alexander J E; Byrne, Helen M


    The retina confers upon us the gift of vision, enabling us to perceive the world in a manner unparalleled by any other tissue. Experimental and clinical studies have provided great insight into the physiology and biochemistry of the retina; however, there are questions which cannot be answered using these methods alone. Mathematical and computational techniques can provide complementary insight into this inherently complex and nonlinear system. They allow us to characterise and predict the behaviour of the retina, as well as to test hypotheses which are experimentally intractable. In this review, we survey some of the key theoretical models of the retina in the healthy, developmental and diseased states. The main insights derived from each of these modelling studies are highlighted, as are model predictions which have yet to be tested, and data which need to be gathered to inform future modelling work. Possible directions for future research are also discussed. Whilst the present modelling studies have achieved great success in unravelling the workings of the retina, they have yet to achieve their full potential. For this to happen, greater involvement with the modelling community is required, and stronger collaborations forged between experimentalists, clinicians and theoreticians. It is hoped that, in addition to bringing the fruits of current modelling studies to the attention of the ophthalmological community, this review will encourage many such future collaborations. PMID:27063291

  2. Patterns of cell proliferation and rod photoreceptor differentiation in shark retinas.

    Ferreiro-Galve, Susana; Rodríguez-Moldes, Isabel; Anadón, Ramón; Candal, Eva


    We studied the pattern of cell proliferation and its relation with photoreceptor differentiation in the embryonic and postembryonic retina of two elasmobranchs, the lesser spotted dogfish (Scyliorhinus canicula) and the brown shyshark (Haploblepharus fuscus). Cell proliferation was studied with antibodies raised against proliferating cell nuclear antigen (PCNA) and phospho-histone-H3, and early photoreceptor differentiation with an antibody raised against rod opsin. As regards the spatiotemporal distribution of PCNA-immunoreactive cells, our results reveal a gradual loss of PCNA that coincides in a spatiotemporal sequence with the gradient of layer maturation. The presence of a peripheral growth zone containing pure-proliferating retinal progenitors (the ciliary marginal zone) in the adult retina matches with the general pattern observed in other groups of gnathostomous fishes. However, in the shark retina the generation of new cells is not restricted to the ciliary marginal zone but also occurs in retinal areas that contain differentiated cells: (1) in a transition zone that lies between the pure-proliferating ciliary marginal zone and the central (layered) retina; (2) in the differentiating central area up to prehatching embryos where large amounts of PCNA-positive cells were observed even in the inner and outer nuclear layers; (3) and in the retinal pigment epithelium of prehatching embryos. Rod opsin immunoreactivity was observed in both species when the outer plexiform layer begins to be recognized in the central retina and, as we previously observed in trout, coincided temporally with the weakening in PCNA labelling. PMID:19822206

  3. The Retinome – Defining a reference transcriptome of the adult mammalian retina/retinal pigment epithelium

    Goetz Thomas


    Full Text Available Abstract Background The mammalian retina is a valuable model system to study neuronal biology in health and disease. To obtain insight into intrinsic processes of the retina, great efforts are directed towards the identification and characterization of transcripts with functional relevance to this tissue. Results With the goal to assemble a first genome-wide reference transcriptome of the adult mammalian retina, referred to as the retinome, we have extracted 13,037 non-redundant annotated genes from nearly 500,000 published datasets on redundant retina/retinal pigment epithelium (RPE transcripts. The data were generated from 27 independent studies employing a wide range of molecular and biocomputational approaches. Comparison to known retina-/RPE-specific pathways and established retinal gene networks suggest that the reference retinome may represent up to 90% of the retinal transcripts. We show that the distribution of retinal genes along the chromosomes is not random but exhibits a higher order organization closely following the previously observed clustering of genes with increased expression. Conclusion The genome wide retinome map offers a rational basis for selecting suggestive candidate genes for hereditary as well as complex retinal diseases facilitating elaborate studies into normal and pathological pathways. To make this unique resource freely available we have built a database providing a query interface to the reference retinome 1.

  4. Spatiotemporal distribution of 1P1 antigen expression in the plexiform layers of developing chick retina



    Changes in the distribution of 1P1-antigen in the developing chick retina have been examined by indriect immunofluorescence staining technique using the novel monoclonal antibody(MAb)1P1.Expression of the 1P1 antigen was found to be regulated in radial as well as in tangential dimension of the retina,being preferentially or exclusively located in the inner and outer plexiform layers of the neural retina depending on the stages of development ,With the onset of the formation of the inner plexiform layer 1P1 antigen becomes expressed in the retina.With progressing differentiation of the inner plexiform layer 1P1 immunofluorescence revealed 2 subbands at E9 and 6 subands at E18,At postnatal stages(after P3) immunoreactivity was reduced in an inside-outside sequence leading to the complete absence of the 1P1 antigen in adulthood.1P1 antigen expression in the outer plexiform layer was also subject to developmental regulation.The spation-temporal pattern of 1P1 antigen expression was correlated with the time course of histological differentation of chick retina,namely the synapse rich plexiform layers.Whether the 1P1 antigen was functionally involved in dendrite extension and synapse formation was discussed.

  5. Wnt signaling in form deprivation myopia of the mice retina.

    Mingming Ma

    Full Text Available BACKGROUND: The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. METHODOLOGY/PRINCIPAL FINDINGS: (1 One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control groups. Form-deprivation myopia (FDM was induced by suturing the right eyelid, while the control group received no treatment. After 1, 2, and 4 weeks of treatment, eyes were assessed in vivo by cycloplegic retinoscopic refraction and axial length measurement by photography or A-scan ultrasonography. Levels of retinal Wnt2b, Fzd5 and β-catenin mRNA and protein were evaluated using RT-PCR and western blotting, respectively. (2 Another 96 mice were divided into three groups: control, drugs-only, and drugs+FDM (by diffuser. Experimentally treated eyes in the last two groups received intravitreal injections of vehicle or the proteins, DKK-1 (Wnt-pathway antagonist or Norrin (Wnt-pathway agonist, once every three days, for 4 injections total. Axial length and retinoscopic refraction were measured on the 14th day of form deprivation. Following form-deprivation for 1, 2, and 4 weeks, FDM eyes had a relatively myopic refractive error, compared with contralateral eyes. There were no significant differences in refractive error between right and left eye in control group. The amounts of Wnt2b, Fzd5 and β-catenin mRNA and protein were significantly greater in form-deprived myopia eyes than in control eyes.DKK-1 (antagonist reduced the myopic shift in refractive error and increase in axial elongation, whereas Norrin had the opposite effect in FDM eyes. CONCLUSIONS/SIGNIFICANCE: Our studies provide the first evidence that the Wnt2b signaling pathway may play a role in the

  6. Effect of high potassium on dopamine receptor activity in bovine retina

    In the present study, the hypothesis that dopamine released by light caused a subsensitivity of the dopamine receptor was investigated. Bovine eyes were obtained from a slaughterhouse, and retinas were dissected in a dark room. Filter binding assays were developed to measure agonist and antagonist binding to the dopamine receptor using [3H]dopamine and [3H]SCH 23390, respectively, in a retinal membrane fraction. Adenylate cyclase activation was measured by the production of [32P]cyclic AMP from 32ATP. In desensitization experiments, bovine retinas were incubated for fifteen minutes with 56 mM potassium, which also causes a release of dopamine in retinas were washed, and membranes were prepared. The stimulation of adenylate cyclase evoked by dopamine and radiolabeled agonist and antagonist binding were measured. In the receptor binding characterization studies, the dissociation constant and the maximum number of binding sites were obtained for [3H]dopamine and [3H]SCH 23390 binding

  7. A robust face recognition algorithm under varying illumination using adaptive retina modeling

    Cheong, Yuen Kiat; Yap, Vooi Voon; Nisar, Humaira


    Variation in illumination has a drastic effect on the appearance of a face image. This may hinder the automatic face recognition process. This paper presents a novel approach for face recognition under varying lighting conditions. The proposed algorithm uses adaptive retina modeling based illumination normalization. In the proposed approach, retina modeling is employed along with histogram remapping following normal distribution. Retina modeling is an approach that combines two adaptive nonlinear equations and a difference of Gaussians filter. Two databases: extended Yale B database and CMU PIE database are used to verify the proposed algorithm. For face recognition Gabor Kernel Fisher Analysis method is used. Experimental results show that the recognition rate for the face images with different illumination conditions has improved by the proposed approach. Average recognition rate for Extended Yale B database is 99.16%. Whereas, the recognition rate for CMU-PIE database is 99.64%.

  8. Ontogenic changes of kynurenine aminotransferase I activity and its expression in the chicken retina.

    Rejdak, Robert; Zielinska, Elzbieta; Shenk, Yana; Turski, Waldemar A; Okuno, Etsuo; Zarnowski, Tomasz; Zagorski, Zbigniew; Zrenner, Eberhart; Kohler, Konrad


    Kynurenine aminotransferases are key enzymes for the synthesis of kynurenic acid (KYNA), an endogenous glutamate receptor antagonist. The study described here examined ontogenic changes of kynurenine aminotransferase I (KAT I) activity and its expression in the chicken retina. KAT I activity measured on embryonic day 16 (E16) was significantly higher than at all other stages (E12, P0 and P7). Double labeling with antibodies against glutamine synthetase showed that on P7 KAT I was expressed in Müller cell endfeet and their processes in the inner retina. Since KAT I activity is high in the late embryonic stages, it is conceivable that it plays a neuromodulatory role in the retina during the late phase of embryogenesis. PMID:12782065

  9. Dynamic coupling of pattern formation and morphogenesis in the developing vertebrate retina.

    Picker, Alexander; Cavodeassi, Florencia; Machate, Anja; Bernauer, Sabine; Hans, Stefan; Abe, Gembu; Kawakami, Koichi; Wilson, Stephen W; Brand, Michael


    During embryonic development, pattern formation must be tightly synchronized with tissue morphogenesis to coordinate the establishment of the spatial identities of cells with their movements. In the vertebrate retina, patterning along the dorsal-ventral and nasal-temporal (anterior-posterior) axes is required for correct spatial representation in the retinotectal map. However, it is unknown how specification of axial cell positions in the retina occurs during the complex process of early eye morphogenesis. Studying zebrafish embryos, we show that morphogenetic tissue rearrangements during eye evagination result in progenitor cells in the nasal half of the retina primordium being brought into proximity to the sources of three fibroblast growth factors, Fgf8/3/24, outside the eye. Triple-mutant analysis shows that this combined Fgf signal fully controls nasal retina identity by regulating the nasal transcription factor Foxg1. Surprisingly, nasal-temporal axis specification occurs very early along the dorsal-ventral axis of the evaginating eye. By in vivo imaging GFP-tagged retinal progenitor cells, we find that subsequent eye morphogenesis requires gradual tissue compaction in the nasal half and directed cell movements into the temporal half of the retina. Balancing these processes drives the progressive alignment of the nasal-temporal retina axis with the anterior-posterior body axis and is controlled by a feed-forward effect of Fgf signaling on Foxg1-mediated cell cohesion. Thus, the mechanistic coupling and dynamic synchronization of tissue patterning with morphogenetic cell behavior through Fgf signaling leads to the graded allocation of cell positional identity in the eye, underlying retinotectal map formation. PMID:19823566

  10. Training and professional profile of retinologists in Spain: Retina 2 project, Report 4

    Pastor JC


    Full Text Available J Carlos Pastor1,3, Itziar Fernández2, Jimena Rojas1, Rosa Coco1, Maria R Sanabria1, Enrique Rodríguez-de la Rúa1,3, Diego Sánchez3, Carmen Valverde3, Anna Sala Puigdollers1,31University Institute of Applied Ophthalmobiology (IOBA, Retina Group, 2Ministry of Science and Innovation CIBER-BBN, Statistics Department, 3Clinic University Hospital, University of Valladolid, Valladolid, SpainBackground: Uniform postresidency systems to train medical specialists have not been developed in most European countries. Before developing a framework for such a system, we established the learning and professional profiles of Spanish ophthalmologists dedicated to medical retina and vitreoretina subspecialties.Methods: After identification of presumed subspecialists by experts from different autonomous regions, a self-administered questionnaire was mailed in 2006. A reminder was sent three weeks later. Postal mail was used. Nonresponder bias was determined.Results: Of 492 possible retina subspecialists, 261 replied to the questionnaires. While about 86% received specific retinal training, standardized fellowship programs were uncommon for both medical retina and vitreoretina (around 10%. Of the responders, 24.5% performed only medical retina, 11.8% vitreoretina, and 63.6% both. Most (60.5% practiced anterior segment surgery, and 78.7% declared skills in vitrectomy.Conclusion: We have developed a database of Spanish ophthalmologists dedicated to retinal pathologies and identified some characteristics of their professional profile. Although most of them have received specific retinal training, standardized mastership programs are still uncommon. These data will be useful in creating a standardized Retina Mastership, an important goal of the European Higher Education Area.Keywords: clinical activity, fellowship, mastership, professional profile, retinologist training