Therapy for Vitreous Seeding Caused by Retinoblastoma. A Review.

Retinoblastoma is the most common primary malignant intraocular tumor in children. Seeding, specifically the dispersion of the tumor into the adjacent compartments, represents a major parameter determining the degree of retinoblastoma according to the International Classification of Retinoblastoma. In this article we focused on vitreous seeding, one of the main limiting factors in the successful "eye preservation treatment" of retinoblastoma.

Pleomorphism and Viability of the Lyme Disease Pathogen Exposed to Physiological Stress Conditions: A Correlative Cryo-Fluorescence and Cryo-Scanning Electron Microscopy Study.

To understand the response of the Lyme disease spirochete exposed to stress conditions and assess the viability of this spirochete, we used a correlative cryo-fluorescence and cryo-scanning microscopy approach. This approach enables simple exposition of bacteria to various experimental conditions that can be stopped at certain time intervals by cryo-immobilization, examination of cell viability without necessity to maintain suitable culture conditions during viability assays, and visualization of structures in their native state at high magnification. We focused on rare and transient events e.

Provision and quality assurance of preimplantation genetic diagnosis in Europe.

Preimplantation genetic diagnosis (PGD) is now well established and provided in many European countries. However, regulations, professional standards and accreditation requirements can differ notably. Furthermore, no comprehensive independent data exist either about practice and provision in Europe or about the quality assurance practices and procedures designed to optimize the quality of the results.

The bidirectional phase-shifting effects of melatonin on the arginine vasopressin secretion rhythm in rat suprachiasmatic nuclei in vitro.

In vivo melatonin serves as a feedback signal to the circadian pacemaker located in the suprachiasmatic nuclei (SCN) and in vitro it phase advances the circadian rhythm of electrical activity in pacemaker cells. However, the occurrence and nature of phase shifting in secretion by cultured SCN neurons has not yet been established. Here we studied the effects of melatonin on the pattern of spontaneous arginine vasopressin (AVP) release in organotypic SCN slices.

Effects of melatonin on ischemia and reperfusion injury of the rat heart.

Effects of melatonin on various manifestations of ischemia/reperfusion injury of the isolated perfused rat heart were examined. Ischemia- and reperfusion-induced ventricular arrhythmias were studied under constant flow in hearts subjected to 10, 15 or 25 min of regional ischemia (induced by LAD coronary artery occlusion) and 10-min reperfusion. Melatonin was added to the perfusion medium 5 min before ischemia at concentrations of 10 micromol/l or 10 nmol/l and was present throughout the experiment.