Next-generation sequencing identifies major DNA methylation changes during progression of Ph+ chronic myeloid leukemia.

Little is known about the impact of DNA methylation on the evolution/progression of Ph+ chronic myeloid leukemia (CML). We investigated the methylome of CML patients in chronic phase (CP-CML), accelerated phase (AP-CML) and blast crisis (BC-CML) as well as in controls by reduced representation bisulfite sequencing. Although only ~600 differentially methylated CpG sites were identified in samples obtained from CP-CML patients compared with controls, ~6500 differentially methylated CpG sites were found in samples from BC-CML patients. In the majority of affected CpG sites, methylation was increased. In CP-CML patients who progressed to AP-CML/BC-CML, we identified up to 897 genes that were methylated at the time of progression but not at the time of diagnosis. Using RNA-sequencing, we observed downregulated expression of many of these genes in BC-CML compared with CP-CML samples. Several of them are well-known tumor-suppressor genes or regulators of cell proliferation, and gene re-expression was observed by the use of epigenetic active drugs. Together, our results demonstrate that CpG site methylation clearly increases during CML progression and that it may provide a useful basis for revealing new targets of therapy in advanced CML.

Mapping the human retina.

The new therapeutic method of scotoma-based photocoagulation (SBP) developed at the Vienna Eye Clinic for diagnosis and treatment of age-related macular degeneration requires retinal maps from scanning laser ophthalmoscope images. This paper describes in detail all necessary image analysis steps for map generation. A prototype software system for fully automatic map generation has been implemented and tested on a representative dataset selected from a clinical study with 50 patients. The map required for the SBP treatment can be reliably extracted in all cases. Thus, algorithms presented in this paper should be directly applicable in daily clinical routine without major modifications.

Use of perfluorocarbon liquids in proliferative vitreoretinopathy: results and complications.

BACKGROUND: The present study was set up to evaluate the influence of perfluorocarbon liquids on the postoperative anatomical and functional results as well as on the complication rates in eyes with proliferative vitreoretinopathy (PVR). METHODS: Sixty five consecutive eyes (64 patients) with PVR in different stages requiring surgical intervention where liquid perfluorocarbons were used were compared with 64 consecutive eyes (62 patients) operated without the help of perfluorocarbon immediately before this time. Both groups were similar with regard to severity of PVR, number of operations, and initial visual acuity. The observation period was shorter in the perfluorocarbon group because they were operated more recently (17.4 months as against 24.4 months). RESULTS: The anatomical as well as the functional success rates were not significantly higher in the perfluorocarbon group (69% v 61% and 65% v 53% respectively). However, in cases operated on without perfluorocarbons where reproliferation would occur it was of much greater severity than in cases where perfluorocarbons were used. The number of uncured cases with contraction of the retina at least in the inferior half was more than twice as high in the group operated on without perfluorocarbon. Combined with massive reproliferation secondary glaucoma and bullous or band keratopathy were more frequent in eyes treated before the use of perfluorocarbon. CONCLUSION: The intraoperative use of perfluorocarbon liquids in vitreoretinal surgery does not prevent postoperative reproliferation but does reduce its severity.

The effect of chemical stability and purification of perfluorocarbon liquids in experimental extended-term vitreous substitution.

BACKGROUND: To determine the importance of chemical stability and purification of perfluorocarbon liquids (PFCLs) in experimental retinal tolerance, we tested four different substances as long-term vitreous tamponade: purified and nonpurified perfluorodecalin (PFD) and perfluoro-octyl-bromide (PFOB). METHOD: After mechanical vitrectomy we replaced the vitreous of 65 rabbit eyes. Five groups were formed; four of them received the four PFCLs, while one served as control and received Ringer solution. The eyes were observed clinically every week and examined histologically after 1, 2, 4 and 8 weeks. RESULTS: After 1 week we observed foam cells and intraretinal macrophages in all eyes with PFCLs. Purified PFD caused retinal lesions in the photoreceptor, ganglion cell and outer nuclear layers after only 2 weeks in the lower part of the eyes. In eyes filled with purified PFOB we observed more pronounced damage of the same nature. Unpurified substances caused severe inflammation and retinal detachment. CONCLUSION: Our study demonstrates that purification and chemical stability are important factors in retinal tolerance of PFCLs for vitreous replacement. Although purified PFD was tolerated by the rabbit eyes for 1 week, we cannot recommend this substance for short-term clinical use as a vitreous substitute.

Experimental perforating injury with high energy electrons to inhibit intraocular proliferation.

Since 1980, the fibroblast model creating experimental proliferative vitreoretinopathy has been used to evaluate the antiproliferative effect of various drugs. In previous studies radiation therapy was found to reduce effectively intraocular proliferation in this model. We therefore investigated the effect of high energy electrons in a standard perforating injury model creating a traumatic proliferative vitreoretinopathy. In 36 eyes we performed a 8 mm pars plana incision and injected 0.4 ml of 80% fibronectin solution intravitreally. Ten rabbits (20 eyes) received radiation therapy with a Betatron accelerator in a total dosage of 3000 cGy to each eye divided into 10 single fractions starting on the first post-operative day. Maximum concentration of the dose was focused to the posterior vitreous. The other 9 rabbits, 18 eyes, served as control. In our perforating injury model we observed a reduction of retinal detachment rate of 72% in the controls to 55% in the treated group. The effect of radiation therapy with high energy electrons and total dosage of 3000 cGy was not statistically significant in experimental traumatic proliferative vitreoretinopathy.

Retinal detachment with severe proliferative vitreoretinopathy in Terson syndrome.

BACKGROUND: In several reports, early vitrectomy has been proposed for eyes with vitreous hemorrhage due to Terson syndrome as a means to hasten visual recovery. But the development of nuclear sclerosis and the neurologic problems arising from this disease encourage surgeons to wait for spontaneous resorption, especially with young patients. Although the formation of epiretinal membranes has been described, to the authors' knowledge retinal detachment with proliferative vitreoretinopathy in Terson syndrome never has been observed. METHODS: The authors report five eyes from four patients with Terson syndrome due to spontaneous aneurysm rupture, in whom retinal detachment with proliferative vitreoretinopathy developed. RESULTS: The early onset and the severe clinical course of proliferative vitreoretinopathy in these eyes showed parallels to traumatic proliferative vitreoretinopathy. The retina in all eyes could be reattached. CONCLUSION: The authors point out the necessity for accurate and close follow-up and early, extensive surgical treatment in Terson syndrome, especially in patients with a reduced general state of health.

The antiproliferative effect of fractionized radiation therapy: optimization of dosage.

Fractionized radiation therapy with high-energy electrons have proven to reduce retinal detachment rate from 85% to 5% in the fibroblast model using a dosage of 3000 rad, starting from the first postoperative day. The purpose of this study is to gain more information about the therapeutic range of fractionized radiation therapy in experimental PVR. We therefore investigated the efficacy of this therapy when the total dose is reduced to 2000 rad. Irradiation treatment started on the first postoperative day. Eight weeks after cell implantation 5 of 14 eyes (35%) in the irradiated group and 15 of 16 eyes of the control group (93%) showed traction detachment. The statistically significant result proves a broad therapeutic range of fractionized radiation therapy in experimental PVR. We believe that a combination with antiinflammatory drugs could lead to a dose reduction in both therapies in patients.

Experimental long-term vitreous replacement with purified and nonpurified perfluorodecalin.

Highly purified perfluorodecalin and non-purified perfluorodecalin were injected into 34 rabbit eyes after mechanical vitrectomy, to evaluate the retinal tolerance in long-term vitreous replacement and the effect of purification on the retina. Unpurified perfluorodecalin caused severe inflammation and retinal damage and eight of ten eyes had developed retinal detachment after four weeks. In the eyes injected with highly purified perfluorodecalin, we observed retinal changes of the rod and cone, outer nuclear, and ganglion-cell layers after two weeks, which progressed to a thinning of all layers of the retina by the fourth week and to localized areas of retinal atrophy by the eighth week in the lower part of the eyes. Retinal damage in the upper part occurred after four weeks. At the perfluorocarbon-aqueous interface we observed a band of retinal necrosis that was noticed in all eyes four weeks postoperatively regardless of the substance used.

Irradiation pretreatment before fibroblast implantation in experimental PVR.

Fibroblast injection into the vitreous body causes traction detachment in the rabbit's eye. Various working groups reported different results on the main causes of the development of experimental PVR. These contradictions encouraged us to investigate the main source of experimental PVR by irradiating the ocular tissues before fibroblast implantation thus suppressing cell proliferation originating from host tissue. Over a period of 3 weeks, 22 eyes received ten radiations in a total dosage of 3000 rad. After the last radiation, 250,000 fibroblasts were implanted into 22 eyes. In another 4 eyes, fibroblast implantation but no radiation was carried out. After 8 weeks, 59% of 22 eyes developed different stages of retinal detachment. Comparison with the group of unirradiated eyes, which developed retinal detachment in 85%, revealed no significant differences in the number of detachments.

Ocular findings in asymptomatic amateur boxers.

A group of 25 active, asymptomatic, amateur boxers were examined to evaluate the nature and incidence of ocular pathologic conditions in amateur boxing. An approximately age-matched group of 25 men who were not boxers was used as a control group. The number of fights varied from 1 to 220 (mean 39.4), and the number of spar rounds from 20 to 600 (mean 192.5). Visual acuity was 20/20 in all subjects of both groups, except for one boxer with keratoconus. Intraocular pressure was below 20 mmHg in all eyes. In 19 (76%) boxers, pathologic anatomic findings were attributed to contusion trauma. Lesions of the anterior eye segment included injuries of the lid in 3 eyes (12%), angle abnormalities in 5 (20%), and slight lens opacities in 5 (20%). Posterior vitreous detachment was observed in 3 (12%) boxers and peripheral retinal scars were seen in 15 (60%). In 6 (24%) eyes, retinal tears or atrophic holes were detected. In the 7 (28%) boxers with lesions of the anterior eye segment, the posterior segment was also affected in 6 (85%). In the control group, an atrophic hole was found in one (4%) patient with no other ocular pathologic findings.(ABSTRACT TRUNCATED AT 250 WORDS)