Behavioral alterations and changes in Ca/calmodulin kinase II levels in the striatum of connexin36 deficient mice

Gap junctions (GJ) are intercellular channels which directly connect the cytoplasm of adjacent cells. GJ allow direct cell-to-cell communication via the diffusion of ions, metabolites and second messengers such as IP(3). The connexin36 (Cx36) protein has been detected in GJ between interneurons of the hippocampus, cerebral cortex, striatum, amygdala, the inferior olive, cerebellum and other brain structures, such as the olfactory bulb. Cx36 knockout (Cx36 KO) mice display changes in synchronous network oscillations in the hippocampus, neocortex and inferior olive and exhibit impaired spatial alternation and one-trial object recognition in a Y-maze. Here, we further characterized the behavioral changes induced by Cx36 deficiency in the mouse by using different behavioral measures and experimental procedures. Additionally, we examined the effects of Cx36 deficiency on acetylcholine esterase (AChE) activity and calcium calmodulin kinase II alpha (CaMKII) protein levels in the striatum. The homozygous Cx36 KO mice displayed increased locomotion and running speed in the open-field, reduced object exploration and impaired one-trial object-place recognition. Furthermore, they exhibited more anxiety-like behavior as compared to the heterozygous controls in the light-dark box. Homozygous Cx36 KO mice exhibited reduced CaMKII levels in the striatum as compared to the heterozygous mice. AChE activity in the striatum was not significantly different between groups. The present results suggest that Cx36 deficiency in the mouse leads to reduced CaMKII levels in the striatum and behavioral changes in open-field activity, anxiety-related behavior in the light-dark box and one-trial object-place recognition.

Quality and reproducibility of retinal thickness measurements in two spectral-domain optical coherence tomography machines

PURPOSE

To evaluate the accuracy and reproducibility of retinal thickness measurements in exudative age-related macular degeneration (AMD) by the Spectralis (Heidelberg Engineering, Heidelberg, Germany) and the Cirrus (Carl Zeiss Meditec, Dublin, CA) optical coherence tomography (OCT) systems.

METHODS

Eyes with exudative age-related macular degeneration were randomly assigned to one of eight groups, each different in the sequence of examiner and OCT system. The 512 × 128 cube program of the Cirrus and the 30° × 25° volume scan containing 32 lines of the Spectralis were performed twice. The correlation between the examinations was expressed by the interclass correlation coefficient (ICC).

RESULTS

Enrolled in the study were 112 patients and 112 eyes (mean age, 76.5 ± 7.9 years; range 51-89), with 14 patients in each group. The mean error scores per line were 0.53 and 0.52 in the Cirrus, significantly (P < 0.001) lower than in the Spectralis (0.83 and 0.98). For automatic central retinal thickness (CRT), the ICC for Cirrus (all examinations calculated) was 0.61 for groups 1 to 4 (the same examiner) and 0.65 for groups 5 to 8 (two different examiners); for Spectralis (13.4% not calculated) the ICC was 0.93 for groups 1 to 4 and 0.86 for groups 5 to 8. After error correction, the Cirrus ICC improved to 1.0 and 0.99 and the Spectralis ICC to 1.0 in both groups.

CONCLUSIONS

Considerable differences were found between the two systems, both of which incorporate the spectral-domain technology. Different positioning of segmentation lines, control of localization, density of included scan lines, and number of available maps explain the differences in segmentation quality and reproducibility. Manual correction of segmentation and centralization improves the reproducibility.

Implication of CD21, CD35, and CD55 in the pathogenesis of age-related macular degeneration

PURPOSE

To determine a possible implication of CD21, CD35, and CD55 in the pathogenesis of age-related macular degeneration (AMD) by assessing the difference in expression rates of these factors on AMD patients and a control group.

DESIGN

Case-control study.

METHODS

Fifty unrelated AMD patients and 48 unrelated sex- and age-matched control subjects participated in this case-control study. Samples of fresh EDTA-blood were stained and flow cytometry was chosen to measure fluorescence emissions. The association between exudative AMD and CD21, CD35, and CD55 was evaluated from all patients who completed the study.

RESULTS

Our study shows CD35 to be expressed in a significantly higher frequency in AMD patients on monocytes (P = .00586), lymphocytes (P = .000605), and granulocytes (P < .000033). In contrast, the expression rate of CD21 (P > .05) and CD55 (P > .05) are similar in both groups.

CONCLUSION

More regulative factors of the complement system are involved in pathogenesis of AMD. Our study underlines the key role of the complement system in AMD and shows the involvement of the whole immune system through more regulative factors.

Circulating angiopoietic cells and diabetic retinopathy in type 2 diabetes mellitus, with or without macrovascular disease

PURPOSE

To investigate different types of circulating angiopoietic cells, such as vasculogenic circulating progenitor cells (CPCs), endothelial progenitor cells (EPCs), and mature EPCs (matEPCs) in patients with type 2 diabetes mellitus (T2DM), with or without diabetic retinopathy (DR) and with or without macrovascular disease (MVD).

METHODS

One hundred twenty-six patients with T2DM-66 with MVD and 60 without MVD-were enrolled in a case-control study. MVD comprised coronary heart disease, peripheral arterial disease, stroke, or various combinations of those conditions. By a modified Early Treatment of Diabetic Retinopathy Study (ETDRS) classification, 55 patients were classified without DR (CO), 19 with mild nonproliferative DR (mNPDR), 16 with moderate-severe NPDR (msNPDR), 19 with early proliferative diabetic retinopathy (ePDR), and 17 with high-risk PDR (hrPDR). CPCs (CD34/CD133), EPCs (CD34/CD133/CD30), and matEPCs (CD34/CD133/CD309/CD31) were enumerated by flow cytometry.

RESULTS

Patients with MVD CPCs, EPCs, and matEPCs showed a significant, stepwise decline with advancing stages of retinopathy. In contrast, in the patients without MVD, EPCs and matEPCs reached up to 56% of CPCs and 37% of EPCs. On the other hand, the percentage of EPCs and matEPCs was reduced to 5% of CPCs and EPCs each in MVD patients. Thus, the percentage of EPCs and matEPCs in comparison with that of CPCs and EPCs represented an 11- and 7-fold difference.

CONCLUSIONS

The circulating angiopoietic CPCs, EPCs, and matEPCs in T2DM patients with DR had a different regulations, with increasing relative differences occurring in proliferative DR, apparently depending on the macrovascular comorbidities. Patients with MVD showed a strong retinopathy-stage-dependent depletion of all angiopoietic cells.

Genetic cardiovascular risk factors and age-related macular degeneration

PURPOSE

To investigate the association between genetic cardiovascular risk factors and exudative age-related macular degeneration (AMD) in a White Austrian population.

METHODS

Seventy-five unrelated AMD patients and 75 unrelated healthy, sex- and age-matched control patients were genotyped for the following 19 single nucleotide polymorphisms (SNPs) in 14 different genes: blood coagulation factor V (FV) R506Q, factor II (prothrombin) G20210A and factor XIII (FXIII) V34L; 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C; plasminogen activator inhibitor 1 (PAI-1) 4G/5G; endothelial protein C receptor (EPCR) 4600 A>G (A3 haplotype), 4678 G>C (A1 haplotype); apolipoprotein B (ApoB) R3500Q; apolipoprotein E (ApoE) E2/E3/E4; β-fibrinogen -455 G>A; human platelet antigen 1 (HPA1) a/b; angiotensin-converting enzyme (ACE) I/D; endothelial nitric oxide synthase (eNOS) 786 T>C, 894 G>T; lymphotoxin alpha (LTA) 804 C>A and 9p21 rs10757278. Genotyping was carried out by polymerase chain reaction (PCR) followed by reverse hybridization (CVD StripAssays; ViennaLab Diagnostics, Vienna, Austria).

RESULTS

No statistically significant association could be observed between AMD and the investigated genetic risk factors for cardiovascular disease (CVD). All factors seem to be uniformly distributed in the two groups of AMD patients and healthy controls. Two variables -β-fibrinogen: -455 G>A (p = 0.0786) and apolipoprotein E4 (p = 0.0636) - were not as far from association as the others.

CONCLUSION

Our data show that the 19 tested CVD risk markers do not play a significant role in AMD. β-Fibrinogen and apolipoprotein E4 should be examined in a larger cohort.

In vitro cytotoxicity and phototoxicity study of cosmetics colorants

The aim of the work was early identification of preventable risk factors connected with the consumers usage of products of everyday use, such as cosmetics, toys and children products, and other materials intended for contact with human skin. The risk factor is represented by substances with irritation potential and subsequent possible sensitisation, resulting in negative impact on human physical and psychical health with social and societal consequences. The legislation for cosmetics, chemical substances and other products requires for hazard identification the application of alternative toxicological methods in vitro without the use of animals. For this reason we used a battery of alternative assays in vitro, based on cell cultures. Progressive methods of molecular biology, based on fluorimetry and fluorescence, were employed for identification of early morphological and functional changes on cellular level. Four colorants frequently used in cosmetics (P-WS Caramel, Chlorophyllin, Unicert Red K 7054-J and Unicert Red K 7008-J) were tested on cell line NIH3T3 (mouse fibroblast cell) and 3T3 Balb/c with/without UV irradiation (dose 5 J cm(-2)). Fluorescence methods for the study of cell damage using fluorescence probes offer results for the evaluation of cytotoxicity and cell viability of adherent cells. We detected intracellular production of ROS investigated by molecular probe CM-H(2)DCFDA, which is primarily sensitive to the increased production of hydrogen peroxide or its downstream products. Toxic effects on the cellular level were identified by viability tests using Neutral Red uptake and MTT assay, where the live cells reduce yellow soluble 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) to insoluble formazan crystals. The reaction was investigated on mitochondrial membrane of living cells and the type of cell death was determined using Apoptosis detection kit. Cytotoxicity tests revealed health risks of using Chlorophyllin and Unicert Red K 7054-J.

Human retinal pigment epithelium (RPE) transplantation: outcome after autologous RPE-choroid sheet and RPE cell-suspension in a randomised clinical study

AIMS

To evaluate the outcome after two types of retinal pigment epithelium (RPE) transplantation techniques.

METHODS

Fourteen consecutive patients with advanced exudative age-related macular degeneration (AMD) were randomly assigned to RPE-choroid sheet transplantation (group 1) or RPE cell-suspension transplantation (group 2). Outcome measures included best corrected distance and near visual acuity (BCVA), complication and recurrence rates, autofluorescence (AF), angiography, and time-domain and spectral-domain optical coherence tomography (TD- and SD-OCT).

RESULTS

A gain of three or more lines in BCVA at 24&emsp14;months was found in two patients in group 1 and in one patient in group 2, whereas a loss of vision of three or more lines occurred in one patient in each group. Revision surgery for proliferative vitreoretinopathy was required in one patient in group 1. Epiretinal membranes developed in two patients in group 1 and in one patient in group 2. No recurrence occurred in this series. AF showed hyperfluorescence coincident with the graft in group 1, and hyper- and hypofluorescence in irregular patterns in group 2. Revascularisation of the graft was present in all patients in group 1, and a normal choroidal vasculature in the area of RPE atrophy in all patients in group 2. OCT showed a decrease in retinal thickness in all patients, with an improved visualisation of inter- and intralaminar structures with SD-OCT.

CONCLUSION

The anatomical and functional outcome after both RPE transplantation techniques was comparable. Intrastructural irregularities of the sheet assessed using SD-OCT might explain the rather limited visual gain in otherwise successful sheet transplants. Clinical Trial Registration NCT00401713.

Conversion of Stratus optical coherence tomography (OCT) retinal thickness to Cirrus OCT values in age-related macular degeneration

AIM

Spectral domain optical coherence tomography (SD OCT) is of increasing importance and is gradually replacing time domain OCT (TD OCT). Our aim was to determine a formula to convert Stratus OCT (TD OCT) to Cirrus OCT (SD OCT) retinal thickness.

METHODS

Central retinal thickness (CRT) and retinal volume (RV) were obtained by the macular thickness program of Stratus OCT and the cube 512 × 128 program of Cirrus OCT in patients with exudative age-related macular degeneration (AMD). Algorithm line failures were corrected. A linear model with Stratus OCT CRT as fixed factor and Cirrus OCT CRT as dependent variable was applied to calculate the conversion formula.

RESULTS

OCT examinations of 104 eyes of 104 patients were reviewed and corrected when necessary. Stratus and Cirrus OCT CRT were significantly correlated (p<0.0001). For CRT the formula Cirrus CRT=58.63+0.94 × Stratus CRT was calculated. The correlation was significantly influenced by the height of the CRT values (p<0.0001), but not by whether correction was necessary. For RV the formula Cirrus OCT RV=3.098+0.98 × Stratus OCT RV was calculated.

CONCLUSION

Stratus OCT and Cirrus OCT use a different posterior reference line within the hyper-reflective band of the outer retina. Therefore a conversion formula is necessary to compare Stratus and Cirrus OCT CRT values, and this has been determined in our study.

Comparison of visual performance with blue light-filtering and ultraviolet light-filtering intraocular lenses

PURPOSE

To compare the contrast sensitivity, glare, color perception, and visual acuity at different light intensities with yellow-tinted and clear intraocular lenses (IOLs) by different manufacturers.

SETTING

Ludwig Boltzmann Institute of Retinology and Biomicroscopic Laser-Surgery, Department of Ophthalmology, Rudolf Foundation Clinic, Vienna, Austria.

DESIGN

Comparative case series.

METHODS

Eyes were randomized to 1 of the following IOLs: AF-1 (UY) (yellow tinted), AcrySof SN60AT (yellow tinted), AF-1 (UV) (clear), or AcrySof SA60AT (clear). One week and 2 months postoperatively, monocular contrast sensitivity function and color discrimination were tested and the corrected distance and near visual acuities were evaluated. All tests were performed under different light intensities (10 to 1000 lux).

RESULTS

Of the 80 patients enrolled, 76 completed the study; there were 37 eyes in the yellow-tinted IOL group and 39 in the clear IOL group. There were no significant differences between yellow-tinted IOLs and clear IOLs except in color vision under mesopic conditions (10 lux). Patients with a yellow-tinted IOL made significantly more mistakes in the blue-light spectrum than patients with clear IOLs (P = .00015). There was no significant difference under photopic conditions (1000 lux).

CONCLUSIONS

The yellow-tinted IOLs were equivalent to the clear IOLs in postoperative contrast sensitivity, visual acuity, and color perception under photopic conditions. Patients with yellow-tinted IOLs made statistically significantly more mistakes in the blue range under dim light than patients with clear IOLs.

Outcome after silicone oil removal and simultaneous 360° endolaser treatment

PURPOSE

To evaluate the outcome after silicone oil removal combined with a 360° endolaser treatment in complex retinal detachment (RD) cases and to assess prognostic factors.

METHODS

This is a retrospective, consecutive interventional study in Vienna, Austria with data from 111 patients following silicone oil removal and simultaneous 360° endolaser treatment for at least 6 months. Stepwise regression analysis between anatomic and visual outcome, baseline demographics, and type and number of RD procedures was performed.

RESULTS

One hundred and one patients (91%) showed a retinal reattachment after silicone oil removal, which was associated with a low overall number of RD procedures (p = 0.01) and male gender (p < 0.03). Sixty-five patients (59%) showed an improvement (two or more lines) of best-corrected visual acuity (BCVA) at the final follow-up visit. Improvement of BCVA and a better BCVA after silicone oil removal were associated with a better BCVA before silicone oil removal (p < 0.01) and a low overall number of RD procedures (p < 0.01).

CONCLUSION

The overall number of RD procedures can be used to predict the anatomic and visual outcome after silicone oil removal. Adding a simultaneous 360° endolaser therapy to silicone oil removal is associated with a high anatomic success rate and an excellent visual outcome.

Spectral domain optical coherence tomography for higher precision in the evaluation of vitreoretinal adhesions in exudative age-related macular degeneration

AIM

The role of changes at the vitreoretinal interface and vitreomacular traction forces in pathogenesis, and the course of exudative age-related macular degeneration (AMD) need further exploration. This study examines the localisation of adhesion and the direction of traction lines in eyes with exudative AMD.

METHODS

The cubes 512×128 of Cirrus optical coherence tomography (OCT) and volume scans of Spectralis OCT were reviewed in a consecutive series of patients presenting between December 2008 and March 2009 with vitreomacular adhesion in exudative AMD.

RESULTS

30 eyes of 25 patients with exudative AMD and vitreomacular adhesion were studied. 50% had type III lesions, 46.7% occult and 3.3% predominantly classic lesions. The localisation of the adhesion corresponded in 100% with the area of the neovascularisation (CNV), in 73.3% traction directed towards the CNV and in 83.3% towards the optic disc could be noted. Spectral domain OCT and 3D visualisation enabled clearer localisation of vitreomacular adhesion and definition of resulting traction lines.

CONCLUSION

There is a high prevalence of type III lesions within eyes with vitreomacular adhesions, and complete correspondence between the location of the adhesion and the CNV. There is also a high incidence of vitreopapillary adhesion in these cases, suggesting a possible role in pathogenesis.

Serum VEGF and CFH in exudative age-related macular degeneration

PURPOSE

To determine serum vascular endothelial growth factor 165 (VEGF165) levels and the association of the complement factor H gene (CFH) Y402H polymorphism in patients with exudative age-related macular degeneration (AMD) in comparison to unaffected control subjects.

METHODS

Sixty-six AMD patients and 66 healthy age- and gender-matched controls were included in this case-control study. The serum VEGF165 was assayed by ELISA (R&D). Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Chi-squared tests were used regarding the polymorphism, a t-test regarding the VEGF-levels.

RESULTS

Levels of serum VEGF165 were similar in both groups (p-value = 0.2112). Genotype frequency differed significantly between patients with exudative AMD and the healthy control group (p  =  0.003136). The serum VEGF165 levels were similar irrespective of the presence of the CFH Y402H polymorphism (p  =  0.4113) and independent of the specific genotype (p  =  0.9634).

CONCLUSION

In the present study, exudative AMD is not associated to serum VEGF165 levels; furthermore, our data does not establish a statistical link between VEGF165 and the CFH Y402H polymorphism.

High-definition optical coherence tomography in a case of congenital hypertrophy of the retinal pigment epithelium

The authors describe the use of high-definition optical coherence tomography (HD-OCT) in a case of congenital hypertrophy of the retinal pigment epithelium. A 40-year-old woman presented with a large flat pigmented lesion in the inferior retinal quadrant of the left eye, which was compatible with congenital hypertrophy of the retinal pigment epithelium. The lesion was studied with HD-OCT (5 line raster and macular cube 512 × 128) and the results were compared with those of the fellow eye. The volume of the cube in the normal eye measured 7.1 mm(3), whereas the volume of the cube with the lesion was 6.7 mm(3). The subfield thickness analysis was 153 μm in the eye with congenital hypertrophy of the retinal pigment epithelium and 188 μm in the fellow eye, showing a difference of 35 μm between the two eyes. Congenital hypertrophy of the retinal pigment epithelium studied with HD-OCT showed loss of the junction layer between the inner and outer segment of photoreceptors and of the outer nuclear layer.

Phototoxic effect of TPPS4 and MgTPPS4 on DNA fragmentation of HeLa cells

Photodynamic therapy (PDT) is an alternative method of tumour treatment. It is based on a photochemical reaction of a photosensitizer, irradiation, and O(2) which converts to cytotoxic (1)O(2) and other forms of reactive oxygen species (ROS). The comet assay (also called single-cell gel electrophoresis, SCGE) is a sensitive, simple and quantitative technique for detection of DNA damage. In our study we investigated the phototoxicity of the two porphyrin photosensitizers, TPPS4 and MgTPPS4, on HeLa cells. Three different radiation doses and six different concentrations of the photosensitizers were used. Our results show that the DNA of the cells treated with the TPPS(4) and MgTPPS(4) at the concentrations higher than 5 μM was highly fragmented indicating a strong phototoxic effect resulting in a cell apoptosis. On the base of our results we can hypothesize that even the irradiation dose of 1 J cm(-2) is sufficient enough to provoke the DNA fragmentation.