PubMed Health⌕ Search

Biomedical subjects

H Doyle

Publications and source records attributed to H Doyle.

28 records · Page 2Linked to original sources
PubMed1993

Recent advances in hepatic transplantation at the University of Pittsburgh.

FK506 undoubtedly improved the survival advantage of hepatic allotransplantation. Hepatic-intestinal and multivisceral transplantation has also become a feasible therapy for patients with combined intestinal and liver failure. With better understanding of the immunologic and metabolic aspects of allo- and xenotransplantation, further clinical attempts to transplant animal organs to humans may be considered with the hope for a better outcome in the very near future.

Academic Medical Centers↗
PubMed1987

Characterization and localization of the even-skipped protein of Drosophila.

On the basis of homeo box cross-homology we have isolated the pair-rule gene even-skipped (eve) of Drosophila. The eve transcription unit appears to be less than 1.5 kb in length, and encodes a single mRNA of approximately 1.4 kb. The nucleotide sequence of genomic and cDNA clones indicates that the eve protein is composed of 376 amino acid residues, and that its homeo domain shares only approximately 50% amino acid identity with the homeo domains of previously characterized genes. Using antibodies raised against a beta-galactosidase fusion protein we show that the eve protein is distributed in a series of seven transverse stripes at the cellular blastoderm stage, and is localized primarily within the nuclear regions of those embryonic cells that express the gene. After gastrulation, seven weakly stained stripes of eve expression appear, resulting in a transient pattern that consists of a total of 14 evenly spaced stripes. Both the original and new stripes gradually disappear during germ band elongation. A second expression pattern emerges during neurogenesis, whereby eve protein is detected in discrete subsets of neurons in each of the ventral ganglia.

Amino Acid Sequence↗
PubMed1987

Molecular characterization of the zerknüllt region of the Antennapedia gene complex in Drosophila.

zerknüllt (zen) is unique among the 18 known homeo box genes in Drosophila since it is required for the differentiation of the dorsal-ventral pattern, and does not appear to be involved in the process of segmentation. Here we show that the zen region of the Antennapedia complex (ANT-C) consists of two closely linked homeo box genes, designated z1 and z2. The z1 and z2 transcription units show essentially identical patterns of expression during early development, which are consistent with the timing and sites of zen+ gene activity. The putative proteins encoded by z1 and z2 are highly divergent and are related only by virtue of homeo box homology. We have used P-element-mediated germ line transformation to show that z1 alone can provide zen+ gene function, suggesting that the z2 gene might be dispensable. The occurrence of closely linked homeo box genes that display similar patterns of expression is not unique to the zen locus. Such gene duplications might provide important clues to the evolution of the homeo box gene family in Drosophila and other organisms.

Amino Acid Sequence↗
PubMed1985

Distribution of neurotensin in the canine gastrointestinal tract.

The distribution of immunoreactive neurotensin in the canine gastrointestinal tract from the esophagus to the rectum, as well as in the pancreas, was determined by a specific neurotensin radioimmunoassay. Immunoreactive neurotensin was found throughout the gastrointestinal tract and in the pancreas. The highest concentrations of immunoreactive neurotensin were found in the mucosal extracts of the jejunum (422 +/- 68 ng/gm) and ileum (3025 +/- 289 ng/gm). Small but substantial amounts of immunoreactive neurotensin were found in the esophagus, fundus (includes fundus and corpus), antrum, duodenum, colon, and pancreas. The concentrations of neurotensin in the mucosal extracts of the jejunum and ileum increased in a graded fashion from the proximal jejunum to the distal ileum. The neurotensin concentration in extracts of the seromuscular layers of jejunum (73 +/- 14 ng/gm) and ileum (187 +/- 38 ng/gm) were statistically higher in comparison with other gut loci.

Animals↗
PubMedDate not supplied

Maternal regulation of zerknüllt: a homoeobox gene controlling differentiation of dorsal tissues in Drosophila.

The homoeobox gene zerknüllt (zen) plays an important role in the differentiation of dorsal tissues during Drosophila development. zen- embryos show transformations in the dorsal-most regions of the fate map, and lack several tissues that normally derive from these regions, including the amnioserosa and optic lobe. zen displays a simple dorsal on/ventral off pattern as early as cleavage cycle 10-11 (ref. 2). We have prepared a polyclonal antibody against a full-length zen protein, and used this to examine its pattern of expression in mutants that disrupt dorsal-ventral polarity. Most or all of the maternally expressed genes that are involved in this process have been previously identified and fall into two classes, so called 'dorsalizers' and 'ventralizers' (see refs 4-7, reviewed in ref. 8). On the basis of our analysis of zen expression in each of these maternal mutants we propose that one or more of the dorsalizing genes encodes a repressor which inhibits the expression of zen in ventral regions of developing embryos. The ventralizing gene cactus might play an important role in restricting the activity of this repressor to ventral regions, thereby permitting the activation of zen in those dorsal tissues where its function is critically required.

Animals↗