PubMed Health⌕ Search

Biomedical subjects

A L Price

Publications and source records attributed to A L Price.

8 recordsLinked to original sources
PubMed1998

Hox gene expression reveals regionalization along the anteroposterior axis of the zebrafish notochord.

The vertebrate Hox genes have been shown to confer regional identity along the anteroposterior axis of the developing embryo, especially within the central nervous system (CNS) and the paraxial mesoderm. The notochord has been shown to play vital roles in patterning adjacent tissues along both the dorsoventral and mediolateral axes. However, the notochord's role in imparting anteroposterior information to adjacent structures is less well understood, especially as the notochord shows no morphological distinctions along the anteroposterior axis and is not generally described as a segmental or compartmentalized structure. Here we report that four zebrafish hox genes: hoxb1, hoxb5, hoxc6 and hoxc8 are regionally expressed along the anteroposterior extent of the developing notochord. Notochord expression for each gene is transient, but maintains a definite, gene-specific anterior limit throughout its duration. The hox gene expression in the zebrafish notochord is spatially colinear with those genes lying most 3' in the hox clusters having the most anterior limits. The expression patterns of these hox cluster genes in the zebrafish are the most direct molecular evidence for a system of anteroposterior regionalization of the notochord in any vertebrate studied to date.

Animals↗
PubMed1996

Green fluorescent protein marks skeletal muscle in murine cell lines and zebrafish.

The green fluorescent protein (GFP) acts as a vital dye upon the absorption of blue light. When the gfp gene is expressed in bacteria, flies or nematodes, green fluorescence can be directly observed in the living organism. We inserted the cDNA encoding this 238-amino-acid (aa) jellyfish protein into an expression vector containing the rat myosin light-chain enhancer (MLC-GFP) to evaluate its ability to serve as a muscle-specific marker. Transiently, as well as stably, transfected C2C12 cell lines produced high levels of GFP distributed homogeneously throughout the cytoplasm and was not toxic through several cell passages. Expression of MLC-GFP was strictly muscle-specific, since Cos 7 fibroblasts transfected with MLC-GFP did not fluoresce. When GFP and beta Gal markers were compared, the GFP signal was visible in the cytoplasm of the living cell, whereas visualization of beta Gal required fixation and resulted in deformation of the cells. When the MLC-GFP construct was injected into zebrafish embryos, muscle-specific gfp expression was apparent within 24 h of development. gfp expression was never observed in non-muscle tissues using the MLC-GFP construct. Transgenic fish continued to express high levels of gfp in skeletal muscle at 1.5 months, demonstrating that GFP is an effective marker of muscle cells in vivo.

Animals↗
PubMed1994

Laparoscopic colorectal surgery: a challenge for ET nurses.

A growing number of colorectal procedures are being performed either partially or totally by laparoscope. Because of the lack of a major incision, this approach offers numerous advantages, including reduced postoperative pain and shorter recovery time. To familiarize ET nurses with the laparoscopic technique, this article reports a case of laparoscopic abdominoperineal resection and discusses some of the special considerations involved in patient care.

Colostomy↗
PubMed1989

Loss of D1 and D2 dopamine receptors and muscarinic cholinergic receptors in rat brain following in vitro polytron homogenization.

The receptor specific binding of [3H]SCH23390 and [3H]spiperone to rat striatal membranes and [3H]QNB to rat cortical membranes was significantly reduced if the membrane suspensions were subjected to polytron homogenization. The degree of loss of the binding sites was a function of the polytron speed (setting) and the length of time of homogenization. Although the loss of binding sites could be reduced by maintaining a cold temperature of the tissue suspension during polytron homogenization, significant loss of binding sites could not be prevented. As many as 75% of the binding sites could be lost following polytron homogenization under the conditions employed in the present experiments. However, no significant change in the affinity of the remaining binding sites was observed. The loss of binding sites is not likely due to small tissue fragments passing through the filters. Care should be taken during tissue homogenization using a polytron or similar equipment to ensure that loss of receptor binding sites is minimized or remains constant between individual samples.

Animals↗
PubMed1982

A reproducible sodium-lithium countertransport assay: the outcome of changing key laboratory parameters.

This paper describes experimental conditions for reproducible measurement of sodium-lithium countertransport in red blood cells. The assay is sensitive to temperature (10% per degree C) and the condition of the red cells; it is affected little by changes in intracellular lithium over the range 2-7 mmol/1 or by red cell concentrations with laboratory hematocrits of 0.03 to 0.07. Repeated measurements of the same subjects give day-to-day coefficients of variation of 10% or less. The mean difference for interlaboratory comparisons is 11%.

Biological Transport↗