Heterochromatin condensation in central and peripheral nuclear regions of maturing lymphocytes in the peripheral blood of patients suffering from B chronic lymphocytic leukemia - a cytochemical study.

The present study was undertaken to provide complementary information on heterochromatin condensation in central and peripheral nuclear regions during maturation of human leukemic lymphocytes using simple image processing and DNA image densitometry at the single cell level. Such approach indicated that the heterochromatin condensation in perinucleolar and extranucleolar "gene rich" central nucleolar regions preceded that in the "gene poor" nuclear periphery at the nuclear membrane. Thus, the maturation of lymphocytes was accompanied by a marked increase of the heterochromatin condensation at the nuclear membrane that reflected the maturity of these cells. In addition, in contrary to the nuclear size, no substantial differences of the heterochromatin condensation in central and peripheral nuclear regions were noted between untreated and treated patients with cytostatic therapy at the time of taking samples for the present study. On the other hand, the larger heterochromatin condensation in central nuclear regions occasionally persisted in small mature lymphocytes of all studied patients. Such phenomenon might represent the return to the cell cycle or a further type of maturation asynchrony that in leukemic cells is not exceptional.

[Personal experience in the treatment of proliferative diabetic retinopathy using an argon laser]. / Nase zkusenosti v lécbe proliferativní diabetické retinopatie argonovým laserem.

The authors evaluate a group of 44 eyes treated by panretinal photocoagulation by means of an argon laser on account of proliferative diabetic retinopathy. Complete regression of neovascularizations was achieved in 64%, partial regression in 23%, treatment failed in 13%. The resulting visual acuity of 6/12 or better was achieved in 57%, at least stabilization of visual acuity was achieved in 80%, the mean follow-up period being 2.3 years. The results of treatment with an argon laser was analyzed also separately for proliferative diabetic retinopathies of different grades. The authors confirm that advanced stages of proliferative diabetic retinopathy respond more poorly to panphotocoagulation and explain this by an assumed certain grade of autonomy in very advanced proliferative diabetic retinopathy. Therapeutic failure was observed only in a group of eyes with very advanced proliferative retinopathy. The authors also confirm the observation, that if a positive response to laser therapy develops within 3-6 weeks, this is a favourable prognostic sign. In neovascularizations of the retina they observed a more favourable response to panphotocoagulation than in neovascularizations on the disc of the optic nerve.

Present views of the pathogenesis and treatment of central serous chorioretinopathy.

The central serous chorioretinopathy is a disease which has been known since 1866. Even the papers published in recent time did not report anything unequivocal concerning its etiology which remains obscure. A year ago, Spitznas submitted a new interesting working hypothesis to explain the pathogenesis of this disease. At present, in the treatment of CSCH, the method of choice is the direct laser photocoagulation. The best results are so far obtained with the treatment using the red crypton laser beam. This is due to its biological effects on the tissues of the eye. The effects of the selected green beam of the argon laser are similar to those of the red crypton light. In accordance with our experiences, its application is useful for direct photocoagulation of CSCH. It does not lead to the development of a positive central scotoma and that not even in close proximity of the foveola up to the distance of 200 microns from the avascular zone. This is given by its biological effects and the small extent of the coagulated area of the retina. When the leakage is nearer than 200 microns from the margin of the avascular zone of the foveola, it is suitable to treat CSCH conservatively. The risk of a permanent iatrogenic damage of the central visual acuity or the development of subretinal neovascular membranes is minimal on direct photocoagulation of CSCH with green light of the argon laser under simultaneous fluoroscopy, and utilization of suitable parameters of the treatment. The clinician must, however, take this risk into consideration when contemplating the advantage which is gained, namely the shortening of the duration of the disease.

Diabetic maculopathy and cataract extraction.

In 20 diabetic patients with diabetic retinopathy, we followed up the development of diabetic maculopathy after extraction. In 65% of the cases, the arisal or progression of the present macular edema was recorded 2 months after extraction together with a visual impairment. In 4 of them, the visual acuity adjusted itself within 10 months. The cause of this phenomenon may be traction of the vitreous body on the retina or the change in the hemodynamic conditions in the retina after cataract extraction. Since an improvement in the visual acuity occurs only in 30% of the involved eyes, it is recommended to apply the photocoagulation treatment on arisal or deepening of the edema.

Diabetic maculopathy and glaucoma.

Our group of 200 with laser treated diabetics included 5 patients (2.5%) with bilaterally treated primary simple glaucoma. All of them had diabetic maculopathy exclusively within the range of simple diabetic retinopathy. The focal type of maculopathy occurred 5 times, the cystoid 3 times, the ischemic once. There was emphasized the necessity to devote increased care to diabetics with glaucoma because for them glaucoma represents a risk factor regarding the further development of the visual function and the extent of the visual field. On the other hand, the decreased foveolar sensitivity in some diabetics with glaucoma may reduce the visual acuity which thus becomes an unreliable criterion of the success of the laser therapy.

Smokers and diabetic maculopathy.

Of 200 examined diabetic patients with diabetic maculopathy there were 27 smokers, 23 of them diabetics of type II. In comparison with the control group of 23 diabetics with diabetic maculopathy-nonsmokers, the smokers showed a significantly higher incidence of the ischemic type of diabetic maculopathy which, however, did not manifest itself more markedly in their visual acuity.

Treatment of perimacular proliferations in diabetic ophthalmopathy with fluorouracil.

Five eyes from 4 diabetic patients with proliferations perimacularly were treated with fluorouracil after previous unsuccessful treatment with laser therapy. Fluorouracil was administered in two series of five injections each, every second day in daily doses of 10 to 15 mg subconjunctivally. Fluorouracil was well tolerated. It has a certain inhibitory effect (both on vessels and particularly on the formation of the accompanying fibers) on proliferations reaching the macula at a distance from the vessels out of reach of the visual disc, it has no suppressing effect on papilloretinal proliferations.

Mild diabetic rubeosis and panretinal photocoagulation.

In a group of 32 treated and 20 untreated eyes of diabetics with proliferative retinopathy, we applied fluorescein angiography (FAC) of the iris for a period of 5 to 7 weeks to follow up the effect of panretinal photocoagulation (PRP) on mild diabetic rubeosis, which was considered to be a neovascularization of the iris on FAG smaller than 0.5 mm2 in the early phases of the angiogram. The evaluation was carried out by two independent examiners. In the treated group, an improvement occurred in 3 of 32 eyes, in the control group in 2 of 20 eyes. We did not find regression of mild rubeosis after PRP.