Biomedical subjects

U Doll

Publications and source records attributed to U Doll.

5 recordsLinked to original sources

PubMed1998

Functional hand development in tetraplegia.

The development of the 'functional hand' in tetraplegics has been historically facilitated through specialized hand positioning schemes. However, clinical experience at the University Hospital Heidelberg demonstrates no direct relationship between various hand positioning techniques and the probability of functional hand development. The aim of this study was to document the various methods of hand positioning and the resulting functional outcome. In a multi-center study, the paralysed thumb and finger positioning of 64 tetraplegics and the resultant functional outcome was evaluated with a specially developed survey form. Results indicated that the functional outcome of the tetraplegic hand was highly dependent on the level of the spinal cord injury and only to a minor degree dependent upon the different methods of hand positioning employed. The conclusion drawn is that remaining neurologic function after injury determines the final functional outcome of the tetraplegic hand.

Adolescent↗

PubMed1996

A caudal-type homeobox gene activity associated with the development and regeneration of the liver.

Indirect evidence suggests that a chicken homologue to caudal, CHox-cad, might be involved in the development of endoderm-derived tissues and in the regeneration of the adult intestinal epithelium. Using the adult liver as an experimental system, we have investigated whether CHox-cad expression can be induced by a regenerative stimulus following partial hepatectomy. Under conditions of normal growth, CHox-cad is expressed in the embryonic but not in the adult liver. In the regenerating adult liver, immunohistochemical analyses and in situ hybridization experiments revealed a varying CHox-cad expression pattern extending from 6 h to 11 days posthepatectomy. Early in regeneration, 6 h and 18 h after partial hepatectomy, CHox-cad expression is confined to hepatocytes present in the periphery of the lobuli and to putative hepatic progenitor cells in the portal spaces. At later stages, from 30 h posthepatectomy onwards, CHox-cad activity is detected predominantly in cells of the hepatic progenitor cell compartment, the portal spaces. By day 8, CHox-cad-expressing cells have occupied marginal positions in some portal spaces and appear to penetrate into the periportal parenchyma. With progressing regeneration CHox-cad activity gradually declines reaching low levels in cells of a few portal spaces by day 11 post hepatectomy. As expected for a putative transcription factor, CHox-cad protein is localized to the cell nucleus. Immunodetection of PCNA, a marker of cell proliferation, revealed a much more widespread distribution of mitotic cells as compared to CHox-cad-expressing cells. In the region of overlapping expression domains, coexpression of CHox-cad and PCNA in the same cells was rare in most instances. There is evidence to suggest that CHox-cad is involved in the differentiation of liver progenitor cells to mature hepatocytes. The similarity of the CHox-cad expression pattern in the early developing liver and in the adult regenerating liver may indicate the reactivation of a genetic program operative during early stages of liver morphogenesis.

Animals↗

PubMed1995

Differential expression of the chicken Pax-1 and Pax-9 gene: in situ hybridization and immunohistochemical analysis.

We report the cloning, partial sequence analysis, and spatiotemporal expression of the chicken Pax-1 (chPax-1) and Pax-9 (chPax-9) gene, two closely related members of the paired box-containing (PAX) gene family. The chPax-1 gene encodes RNAs of 2.0 and 4.3 kb and a 42 kD protein while the gene products of chPax-9 are represented by 1.9 and 3.1 kb transcripts and a 39 kD protein. In situ hybridization and immunohistochemical analyses reveal chPax-1 expression in the developing pectoral girdle, in cells of the ventral part of sclerotomes, in sclerotome cells of the perichordal tube, and, later in development, in sclerotome-derived cells of the intervertebral disks. Other chPax-1 expression domains detected in the mesenchyme surrounding the atlas and axis and in chondrocytes of immature vertebral bodies, so far unreported for mouse Pax-1, correlate with as yet unexplained malformations in the mouse Pax-1 mutant undulated and Undulated-short tail. Overlapping expression of chPax-1 and chPax-9 is detected in epithelial cells of the embryonic and adult thymus and in cells of the developing intervertebral disks. Unlike chPax-1, however, chPax-9 is not expressed in those perichordal sclerotome cells which are thought to give rise to vertebral bodies. Furthermore, chPax-9 gene products are detected in circumscribed areas of mesenchyme in the metatarsus and in entodermal derivatives, i.e., in the lining epithelium of the developing pharynx and of the embryonic and adult esophagus.

Amino Acid Sequence↗

PubMed1995

Localization of deoxyribonuclease I gene transcripts and protein in rat tissues and its correlation with apoptotic cell elimination.

The expression and distribution of deoxyribonuclease I (DNase I) in rat parotid gland, kidney, small intestine and keratinized epithelium was further analysed at the level of its mRNA by in situ hybridization and correlated to immunohistochemical results using polyclonal anti-DNase I antibodies. High amounts of DNase I-specific mRNA and immunoreactivity were detected in the parotid gland, kidney and small intestine in agreement with previous immunohistochemical results. In the parotid gland, both the DNase I-specific mRNA and antigenicity were detected within the secretory cells. In the kidney, DNase I gene transcripts were localized in distal tubules and the collecting duct system. In this organ an identical localization of DNase I antigenicity was obtained. In the small intestine only the enterocytes covering the villi were shown to express DNase I-specific mRNA; the highest level being detected within the enterocytes along the lower third of the villi. In contrast, the highest level of immunoreactivity was found in enterocytes covering the middle and upper thirds of the villi. Within the stratified epithelium of the tongue, DNase I gene transcription and protein expression started in lower parts of the stratum spinosum and reached into the stratum granulosum. However, the gradient of DNase I gene transcript expression appeared to be shifted to lower layers of the stratum spinosum when compared to DNase I immunoreactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Continued expression of the chicken caudal homologue in endodermally derived organs.

We show that the CHox-cad gene is continuously expressed throughout embryogenesis from Days 1 to 14 of development. In the adult chicken, CHox-cad appears to be expressed exclusively in the gut. Genomic Southern blot hybridization experiments suggest that there may be only a single CHox-cad gene per haploid genome from which RNAs of 2.9 and 1.6 kb are transcribed. In situ hybridization to sections of 80-hr to 12-day chick embryos with a CHox-cad probe reveals that this gene is expressed at high levels in organs of endodermal origin: the developing liver, pancreas, lung, and in the epithelial lining of the entire intestine. By Day 16 of development, CHox-cad signals are observed in the epithelial lining of the gut but no longer in the other endodermally derived organs. The coincidence of CHox-cad expression with the onset of development of these endoderm-derived organs may indicate an important role for that gene during the early steps of organogenesis.

Animals↗