Compartmentalization of HP1 Proteins in Pluripotency Acquisition and Maintenance.

The heterochromatin protein 1 (HP1) family is involved in various functions with maintenance of chromatin structure. During murine somatic cell reprogramming, we find that early depletion of HP1γ reduces the generation of induced pluripotent stem cells, while late depletion enhances the process, with a concomitant change from a centromeric to nucleoplasmic localization and elongation-associated histone H3.3 enrichment. Depletion of heterochromatin anchoring protein SENP7 increased reprogramming efficiency to a similar extent as HP1γ, indicating the importance of HP1γ release from chromatin for pluripotency acquisition. HP1γ interacted with OCT4 and DPPA4 in HP1α and HP1ß knockouts and in H3K9 methylation depleted H3K9M embryonic stem cell (ESC) lines. HP1α and HP1γ complexes in ESCs differed in association with histones, the histone chaperone CAF1 complex, and specific components of chromatin-modifying complexes such as DPY30, implying distinct functional contributions. Taken together, our results reveal the complex contribution of the HP1 proteins to pluripotency.

[18-year survival in a case of repeated excision of malignant conjunctival melanoma]. / Osmnáctileté prezití u opakovaných excizí maligního melanomu konjunktivy.

The case of 18 years survival with repeatedly excised conjunctival malignant melanoma is described. The survival period is extraordinary long in that case. However, the case is illustrative for some general characteristics of conjunctival melanoma, particularly in a comparison with cutaneous melanomas. The importance of regular following of patients with primary acquired melanosis is stressed in conclusion.

[Decentration of posterior chamber intraocular lenses]. / Decentrace zadnekomorových nitroocních cocek.

In a group of 300 patients with a posterior chamber lens in 19% its decentration was found, in 2.3% the iris capture syndrome. The author discusses possible causes of decentration of the implanted lens, possibilities of its therapy.

[Inflammatory intraocular complications after placement of retropupillary lenses]. / Zánetlivé nitroocní komplikace po aplikaci zadnekomorových cocek.

In 194 patients aged 32-81 years 200 retropupillary lenses were administered. 129 lenses were implanted into the sulcus ciliaris, 71 lenses into the lenticular capsule. The surgical technique was the same in both groups. The authors divide inflammatory postoperative complications they encountered into two major groups: cellular reactions on the anterior surface of the lens and fibrinoid reactions with the formation of membranes or synechiae. The authors discuss possible reasons for the development of these complications and possibilities of therapy.

Periosteal Ewing's sarcoma.

Periosteal Ewing's sarcoma is an uncommon, but well documented origin of this malignant condition with radiographic signs, different from intramedullary growing tumours. Imaging modalities like CT or MRI supply proof of macroscopically intact endosteal cortical surface and free medullary cavity in long bones affected by this periosteal type of malignancy. Definite confirmation is valid after a careful microscopic investigation of the resected specimen. The prognosis of this type of Ewing's sarcoma may be more favourable than that of the central type. Early diagnosis and therapy are thus essential. A clinical survey of six observations is given.

[Extramedullary Ewing's sarcoma]. / Mimodrenový Ewinguv sarkom.

The authors refer to six observations of periostal Ewing's sarcoma and describe its X-ray symptomatology. It differs considerably from the commonly known picture of centrally, intramedullar-originated Ewing sarcomas and tumours, diagnosed at considerable advanced stage. The possibility of periosteal origin of Ewing's sarcoma must be considered in differential diagnosis of periostoses and the patients must be examined in a complex way, particularly by computer tomography (and in the future also by MR tomography) in order to demonstrate that the medullar space of the bone is not affected by the tumour. This enables a more considerate resection during the operation. Histological verification of the nature of the tumour and excluding presence of the tumour cells in bone marrow dissection material is necessary. It may be expected that prognosis of this form of Ewing's sarcoma while treated in a modern combined way is more favourable than in the central forms.

[Spinal stenosis]. / Spinální stenóza.

Space conditions in the spine canal play the decisive role in the origin of neurological difficulties connected with pressure on the spinal cord and its radices. For the diagnosis of spinal stenosis the dimensions of the spine canal are of importance: sagital, interpedicular, interarticular and the width of lateral recessus of the spine canal. The diagnostics of spinal stenosis is based on the anterior-posterior and lateral picture of the spine, CT examination and contrast examination of the spine canal--myeloradiculography. CT is included in the diagnostic algorhythm on the 2nd place after picture of the spine in classical projections. The anvantage of CT in its non-invasiveness, illustration without projection distortion and high sensitivity and specificity of the examination. Myeloradiculography is indicated for cases of uncertain findings with CT or discrepancy of the CT picture and clinical condition. It may be presumed that in the near future the CT examination will be required in the diagnosis of spine stenosis more frequently by the physicians.

"Slimy eyes phenomenon" in mice intraperitoneally injected with Pseudomonas aeruginosa cells or cell products.

Mice intraperitoneally treated with various Pseudomonas aeruginosa products or lipopolysaccharides of some selected Enterobacteriaceae representatives were found also to react by an increased slime secretion of the eye conjunctivae. The condition, tentatively designated as "Slimy Eyes Phenomenon", started to develop shortly post-treatment, culminated within 24-48 h when the eyes became fully glued up with slime, and receded 48-72 h later, leaving no sequelae for the eye or the general condition of the animal. No such phenomenon has to date been observed in other laboratory animal species.

Retinal pigment epithelium dystrophy in central serous detachment of sensory epithelium.

The incidence of central serous neuro-epithelial detachment in the polulation living in the health district Prague-10 was found to be one in 22,000 inhabitants a year. The cases were classified into three types: A. Inkblot diffusion 60%; B. upward diffusion 25%; C. congregation type 15%. The site of leakage was usually in the upper part of the detached retina or slightly below the horizontal line. Relapses were observed in 16 out of 79 patients, 20%, usually stemming from the original leak. The average re-attachment time was 98 days. In 10% a chronic course led to extensive dystrophy of the pigment epithelium.