[Nystagmus in ophthalmology]. / Il Nistagmo in Oftalmologia.

Nystagmus is a type of eye movement characterized by alternating smooth pursuit in one direction and saccadic movement in the other direction. Nystagmus may be physiologic when occurring normally and serving its normal function or pathologic when occurring abnormally. The presence of Nystagmus can be benign, or it can indicate an underlying visual or otorhino-neurological problem.Through more and more sophisticated video oculagraphy, video oculoscophy and electronystagmography is possible to study the main characteristics of saccadi such as: amplitude and frequency.In the end it is possible to face the kind of therapy: pharmacological, optical, pleoptic, orthotic, prismatic and surgical.

The application of the differential pH method to the biochemical evaluation of seminal plasma.

OBJECTIVE: To apply the differential pH method to the biochemical evaluation of seminal plasma. DESIGN AND METHODS: Fructose, citric acid and free L-carnitine concentration in human seminal plasma were measured by the differential pH method. These are routinely taken as markers of seminal vesicle, prostate and epididymal function, respectively. The pH differential method was then compared with standard spectrophotometry. RESULTS: The linearity, recovery and imprecision calculation for each assay were found to be reliable and the method correlated well with the reference spectrophotometric technique. In addition, the pH differential method showed certain advantages compared to spectrophotometry: a) speed of procedure (40 to 120 sec/assay); b) ability to measure the analytes even in small volumes of seminal plasma (10 microL to 50 microL) without deproteinization or dilution, thus eliminating manual operations. CONCLUSIONS: The differential pH method is an innovative approach to the biochemical assessment of seminal plasma.

Human sperm cryopreservation and reactive oxygen species (ROS) production.

The aim of this work was to establish whether cryopreservation procedure can trigger the production of Reactive Oxygen Species (ROS) in selected sperm populations. Semen samples were obtained from 45 subjects attending our Department of Medical Pathophysiology. Motile sperm suspensions were obtained by swim-up in Tyrode's salt solution. After dilution with TEST yolk buffer freezing medium, they were cryopreserved in liquid nitrogen. In addition to motility assessment, in basal and freeze/thaw conditions ROS detection and the Hypoosmotic Viability Test were also carried out. In 19 subjects (42.2%) there was already evidence of ROS production prior to cryopreservation, which increased after thawing. In 9 subjects (20.0%) there was no ROS production prior to cryopreservation, however, after freezing/thawing we detected evidence of the presence of ROS. It seems, therefore, that cryoprocedure can indeed provoke or increase ROS production in some semen samples. In ROS producing subjects, the post-show recovery of sperm motility and vitality was significantly lower compared to ROS-free subjects. This was probably due to damage by oxidative stress leading to lipid peroxidation of the sperm membrane. Moreover, in some ejaculates, ROS overproduction or scavenger system failure can be regarded as a cryopathogenetic factor affecting "sperm quality" recovery.