Cerebellar ectopia presenting in adult life

Three cases of cerebellar ectopia first producing symptoms in adult life are reported. This potentially remediable anomaly may not be suspected in adults, in whom associated congenital bony abnormalities of the skull and cervical spine are often absent. In these cases diagnosis depends on radiological contrast studies; in particular it is important to examine the cervical canal in the prone and supine positions.

Cytogenetic and endocrine studies of a freemartin heifer and its bull co-twin

The study of a bovine freemartin and its male co-twin has shown that the sex-reversed gonads of the female are secreting testosterone. Therefore, we suggest that the masculinisation of the freemartin’s reproductive tract may be due to sex hormones secreted by its own gonads, rather than by those from its male co-twin. On the evidence at present available, we favour the view that the female gonad is sex-reversed by a humoral inductor substance coming from the male co-twin that causes retention of the medullary sex cords. A study of the male co-twin suggests that its gonads may also be abnormal in that they secrete reduced amounts of androgen. Both twins showed extensive 60, XX/60, XY chimaerism, with a metacentric marker chromosome associated with the XY cell line only. This was derived from the dam. The proportion of XY cells varied markedly between tissues in both the twins. We were unable to find any germ cells in the female gonad, and, with the exception of one possible female pachytene, all the germ cells examined in the male’s testes were XY.

Fine structure of the early hair germ and dermal papilla in the human foetus

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