Cavernous malformation (CM) is a vascular malformation disorder characterized by a berry-like mass of expanded blood vessels. CM, originating from the optic chiasm. usually leads to chiasma syndrome presenting with bitemporal hemianopsia. We report a 28-year-old male presenting with left homonymous hemianopsia. Magnetic resonance imaging (MRI) revealed an occupied lesion located in the right si...

Three patients with nasal visual field defects are described. In each case it is believed that compression of the lateral fibres of the optic nerve by the anterior cerebral or internal carotid artery was the cause. Binasal hemianopia can thus be produced by a single lesion and is as much a true hemianopia as the common bitemporal one. The value of careful neuroradiological investigation to disp...

Models are presented in which the distribution of crossovers at a four-four-strand stage of meiosis results from a renewal process. Probability distributions are obtained for the number of crossover events on a meiotic bivalent and for the number of exchange points in random meiotic products. These distributions are found to fit the observed distribution of these variables reasonably well. Usin...

Testicular biopsy specimens from 16 fertile and 10 subfertile men with normal male karyotype were studied quantitatively to provide histological and cytogenetic data for a basis of reference in assessing abnormalities of spermatogenesis. Histological studies included estimation of the proportion and activity of germinal epithelium and an assessment of tubular morphology. In cytogenetic preparat...

Lymphocytic hypophysitis (LYH) is an uncommon autoimmune disease in which the pituitary gland is infiltrated by lymphocytes, plasma cells and macrophages and its function is usually impaired. It has to be suspected in pregnant women and in women with recent delivery presenting with hyperprolactinemia, headache, visual field alterations and changes of one or more pituitary hormone secretions wit...

The rearrangement hIn1(I) was isolated as a crossover suppressor for the right end of linkage group (LG) I. By inducing genetic markers on this crossover suppressor and establishing the gene order in the homozygote, hIn1(I) was demonstrated to be the first genetically proven inversion in Caenorhabditis elegans. hIn1(I) extensively suppresses recombination in heterozygotes in the right arm of ch...

The pituitary gland is an endocrine organ that is developmentally derived from a fold in the oral ectoderm and a juxtaposed fold in the neural ectoderm. Here, we show that the absence of Vax1, a homeodomain transcription factor known for its role in eye and optic chiasm development, causes the rostral oral ectoderm to form an ectopic fold that eventually develops into a separate second pituitar...