Identification of c-myc responsive genes using rat cDNA microarray.

c-Myc functions through direct activation or repression of transcription. Using cDNA microarray analysis, we have identified c-Myc-responsive genes by comparing gene expression profiles between c-myc null and c-myc wild-type rat fibroblast cells and between c-myc null and c-myc null cells reconstituted with c-myc. From a panel of 4400 cDNA elements, we found 198 genes responsive to c-myc when comparing wild-type or reconstituted cells with the null cells. The plurality of the named c-Myc-responsive genes that were up-regulated, including 30 ribosomal protein genes, are involved in macromolecular synthesis and metabolism, suggesting a major role of c-Myc in the regulation of protein synthetic and metabolic pathways. When ectopically overexpressed, c-Myc induced a different and smaller set of c-Myc-responsive genes as compared with the physiologically expressed c-Myc condition. Thus, these results from expression profiling suggest a new primary function for c-Myc and raise the possibility that the physiological and transforming functions of c-myc may be separable.

Haemangioma in a cervical lymph node.

Haemangiomas of the head and neck are mainly cutaneous or mucosal; rarely, they may be found in bone or soft tissue. Haemangiomas of lymph nodes are extremely rare; here we present such a case in a cervical lymph node. This is, to the best of our knowledge, only the second report of such an entity.

Rare congenital syndrome associated with profound hearing loss.

In this communication, we describe the otologic and audiometric findings of a rare congenital syndrome associated with profound hearing loss. We offer a hypothesis of the possible inner ear pathologic condition. The major anomalies of this syndrome represent features of an ectodermal dysplasia syndrome.