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Biomedical subjects

A M Arias

Publications and source records attributed to A M Arias.

25 records · Page 2Linked to original sources
PubMed1997

A functional analysis of Notch mutations in Drosophila.

The Notch gene encodes a receptor protein that is involved in many processes during development. Its best understood role is during neurogenesis in a process called "lateral inhibition." However, it has been proposed that Notch also has a role in defining the proneural clusters in the first place. This raises the possibility that the Notch protein is acting as a multifunctional receptor. To test this hypothesis, we have carried out a genetic analysis of molecularly characterized Notch alleles to identify alleles that affect only one of the two proposed functions. Here we present evidence that Notch alleles can be identified that appear to affect the function of Notch during either lateral inhibition or the definition of proneural clusters. In addition our results indicate that there may be discrete regions of the Notch protein required for each function.

Alleles↗
PubMed1991

The embryonic origin of imaginal discs in Drosophila.

The thoracic imaginal discs of Drosophila melanogaster can be observed during embryogenesis as clusters of cells with particular shapes, sizes and behaviours. These structures can be detected soon after germ band shortening and their development appears to be tightly linked to that of the larval epidermis.

Animals↗
PubMed1990

Expression of a MyoD family member prefigures muscle pattern in Drosophila embryos.

We have isolated a Drosophila gene that is expressed in a temporal and spatial pattern during embryogenesis, strongly suggesting an important role for this gene in the early development of muscle. This gene, which we have named nautilus (nau), encodes basic and helix-loop-helix domains that display striking sequence similarity to those of the vertebrate myogenic regulatory gene family. nau transcripts are initially localized to segmentally repeated clusters of mesodermal cells, a pattern that is reminiscent of the expression of the achaete-scute genes in the Drosophila peripheral nervous system. These early nau-positive cells are detected just prior to the first morphological evidence of muscle cell fusion and occupy similar positions as the later-appearing muscle precursors. Subsequently, nau transcripts are present in at least a subset of growing muscle precursors and mature muscle fibers that exhibit distinct segmental differences. These observations establish nau as the earliest known marker of myogenesis in Drosophila and indicate that this gene may be a key determinant of pattern formation in the embryonic mesoderm.

Amino Acid Sequence↗
PubMed1987

Sclerema neonatorum and subcutaneous fat necrosis of the newborn.

Sclerema neonatorum and subcutaneous fat necrosis are rare disorders affecting the panniculus of the newborn. This review attempts to put into perspective their similarities and differences in light of historical, biochemical, pathologic, and etiologic considerations. Recent therapeutic modalities and the prognosis are discussed.

Diagnosis, Differential↗
PubMed1984

Toxic epidermal necrolysis following bone marrow transplantation.

Toxic epidermal necrolysis (TEN) has been reported following bone marrow transplantation. This rare and unfortunate complication may portend fatal outcome. We report on a patient with an allogeneic bone marrow transplant and graft-versus-host disease (GVHD) in whom TEN subsequently developed. In contrast to a previously reported case, our patient survived and is well two years after bone marrow engraftment.

Acute Disease↗
PubMed1982

Familial severe twenty-nail dystrophy.

Severe nail dystrophy is a recently described acquired nail disorder. The nails are variably involved and may show thinning, thickening, pitting, ridging, koilonychia, opalescence, and loss of luster. Not uncommonly, some nails are completely spared. Although most of the cases reported were among children, and nail changes showed gradual resolution, in a few cases the disorder is seen in adulthood. We recently investigated a pedigree extending through five generations in which twenty-one of the thirty-seven members were variably afflicted with the dystrophic nail changes. To our knowledge, the familial pattern, inherited as an autosomal dominant trait, has never been previously reported. We propose the term "familial severe twenty-nail dystrophy" for the disorder in this family.

Adult↗