Effects of heavy ions on visual function and electrophysiology of rodents: the ALTEA-MICE project.

ALTEA-MICE will supplement the ALTEA project on astronauts and provide information on the functional visual impairment possibly induced by heavy ions during prolonged operations in microgravity. Goals of ALTEA-MICE are: (1) to investigate the effects of heavy ions on the visual system of normal and mutant mice with retinal defects; (2) to define reliable experimental conditions for space research; and (3) to develop animal models to study the physiological consequences of space travels on humans. Remotely controlled mouse setup, applied electrophysiological recording methods, remote particle monitoring, and experimental procedures were developed and tested. The project has proved feasible under laboratory-controlled conditions comparable in important aspects to those of astronauts' exposure to particle in space. Experiments are performed at the Brookhaven National Laboratories [BNL] (Upton, NY, USA) and the Gesellschaft für Schwerionenforschung mbH [GSI]/Biophysik (Darmstadt, FRG) to identify possible electrophysiological changes and/or activation of protective mechanisms in response to pulsed radiation. Offline data analyses are in progress and observations are still anecdotal. Electrophysiological changes after pulsed radiation are within the limits of spontaneous variability under anesthesia, with only indirect evidence of possible retinal/cortical responses. Immunostaining showed changes (e.g. increased expression of FGF2 protein in the outer nuclear layer) suggesting a retinal stress reaction to high-energy particles of potential relevance in space.

Stimulus- and event-related evoked potentials: from neuroscience to clinical neuropharmacology.

Synaptic neural (and neural system) functions are peculiarly sensitive to neuroactive compounds. Pharmacological interference/modulation is readily reflected by modifications in the organization of central nervous system (CNS), electrophysiologic signals occurring spontaneously in response to sensory stimulation (stimulus-related or evoked responses) or elicited in conjunction with sensory, motor or cognitive events (event-related potentials). Evoked responses reflect the basic physiology of sensory processes, while event-related potentials combine the time/space resolution of electrophysiologic signals with the specificity of eliciting neuropsychological conditions. The rationale for investigating drug effects on evoked and event-related potentials is manifold. Both are related to sensory and operant behavior and under suitable experimental conditions allow interpretation of drug-related changes in terms of CNS excitability. Some continuity between observations in man and in vivo or in vitro animal data is often possible. Proper handling of the stimulus physical properties or experimental/situational links may allow the responses to be related to sensory input or to neuropsychological manipulation of selectively activated CNS functions or functional subsystems and therefore to control spontaneous variability. This review summarizes today's knowledge of the application of electrophysiology to human neuropharmacology, with due reference to basic pharmacology and experimental evidence.

X-linked mental retardation, microcephaly, and growth delay associated with hereditary bullous dystrophy macular type: report of a second family.

We report on 2 patients with mental retardation and bullous dystrophy, macular type. The observation of the condition in a male and his maternal uncle is consistent with recessive X-linkage. Due to the rarity of the condition, nosologic definition was difficult before the birth of the propositus. The clinical picture in the two patients described, characterized by mental retardation, dwarfism, microcephaly, alopecia, bullous dystrophy macular type, hypogenitalism, is very much like the one observed in the patients, all males, belonging to the only other family reported to date. The recent localization of the bullous dystrophy gene in the Xq24-qter segment opens the possibility of prenatal diagnosis.

Lethal short rib syndrome of the Beemer type without polydactyly.

A new case of Beemer short-rib dwarfism is reported and the clinical and radiological differences between this and Majewski type are discussed. The clinical variability related to the lack or presence of polydactyly is underlined, together with the importance of prenatal diagnosis.

[Spondylo-costal dysostosis: presentation of a new case with autosomal dominant heredity and discussion of problems in genetic counseling]. / Disostosi spondilo-costale: presentazione di un nuovo caso ad ereditarietà autosomica dominante e discussione delle problematiche della consulenza genetica.

The Authors report a new family with spondylo-costal dysplasia in which three members in three generation are affected. The genetic heterogeneity of the condition and its implication in genetic counseling is discussed.

Hypomelanosis of Ito associated with chromosomal translocation involving Xp11.

We report on a 3-year-old girl with hypomelanosis of Ito (HI). She has typical skin lesions and mild CNS involvement characterized by impaired walking and borderline mental retardation. Cytogenetic investigation showed a 18/X translocation with breakpoint on Xp11. This is the sixth case of HI in which this breakpoint has been reported, underlining that this event cannot be considered coincidental. Further studies are needed to understand the etiologic and pathogenetic meaning of this finding.