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M McAvoy

Publications and source records attributed to M McAvoy.

6 recordsLinked to original sources
PubMed1985

"Carryback": effect of viscous liquid controls on the preceding sample analyzed with the SMA II continuous-flow analyzer.

We systematically studied the "carryback" effect of ethylene glycol-based controls on the preceding sample on an SMA II continuous-flow analyzer. Including Beckman Level 1 unassayed liquid control material as a sample lowered the 12 analyte values of the preceding sample by an average of 2.7%, Level 2 (the most viscous) by an average of 4.4%, and Level 3 by 3.2%. Water-reconstituted lyophilized control material caused no carryback effect, but lyophilized control reconstituted with 330 mL/L ethylene glycol decreased the preceding sample's results by 4.1% (average carryback). We believe that carryback is caused by the drag placed on the sample line by a viscous sample, which decreases the volume of the preceding sample that is delivered to the reagent or pre-dilution mixing coils. Our findings were confirmed on another SMA II. Limited study of a SMAC analyzer gave inconclusive results, but further evaluation of continuous-flow systems for carryback is warranted. Carryback substantially increases total analytical variability.

Autoanalysis↗
PubMed1983

Assignment of the human phosphoserine phosphatase gene (PSP) to the pter leads to q22 region of chromosome 7.

Phosphoserine phosphatase (PSP) catalyzes the hydrolysis of phosphoserine to serine. PSP expression has been examined in human-mouse somatic cell hybrids retaining different combination of human chromosomes. Human PSP is expressed only when the pter leads to q22 segment of the human 7 and its enzyme marker beta-glucuronidase (GUSB) are retained in cell hybrids. The structural gene, PSP, is therefore assigned to this region of the human 7.

Animals↗
PubMed1981

Assignment of LIPA, associated with human acid lipase deficiency, to human chromosome 10 and comparative assignment to mouse chromosome 19.

The genetics of lysosomal acid lipase (LIP) has been investigated in human-Chinese hamster and mouse-Chinese hamster somatic cell hybrids. Cellulose acetate electrophoresis of human fibroblast extracts demonstrated that LIP activity consists of three isozymes. A deficiency of LIP activity has been observed in Wolman's disease (WD), cholesterol ester storage disease (CESD), and I-cell disease (ICD); this deficiency was associated with only one LIP isozyme, LIPA. We have demonstrated concordant segregation between human LIPA and human chromosome 10 and its enzyme marker glutamate oxaloacetate transaminase-1 (GOT1) in cell hybrid clones. Previous evidence suggested the different mutations associated with WD and CESD to be in the structural gene which we assign to human chromosome 10, while a different gene, involved in the processing of LIPA, is altered in ICD. These results indicate that several types of gene products are involved in the final expression of LIPA. In mouse-Chinese hamster hybrid clones, mouse Lip-1 (homologous to human LIPA) was assigned to chromosome 19. Previously, mouse Got-1 has been assigned to chromosome 19. Thus, the LIPA-GOT1 linkage groups has remained intact during the 80 X 10(6) years of evolution that separates humans and mice.

Animals↗
PubMedDate not supplied

Agrin mRNA expression in the developing chick Edinger-Westphal nucleus.

Agrin is a large extracellular matrix protein that directs the accumulation of acetylcholine receptors at the neuromuscular junction. Recent evidence suggests that agrin may be involved in organizing synapses in the visual system as well. Focussing on the pathway that controls accommodation and pupilloconstriction, this study examined the temporal pattern of agrin expression with reference to the organization of cholinergic synapses between embryonic chick Edinger-Westphal and ciliary ganglion neurons. In situ hybridization with an S35-labeled agrin cRNA probe was used to characterize agrin expression in the Edinger-Westphal nucleus during development. Agrin mRNA was detected in the Edinger-Westphal nucleus at all time points studied, from embryonic day 7 (E7, Hamburger and Hamilton stage 31) through newly hatched chicks. Throughout this period, agrin mRNA expression in Edinger-Westphal neurons was lower than in nearby oculomotor and trochlear neurons, suggesting that cells projecting to neuronal targets may require less agrin than those projecting to muscle. Agrin mRNA expression in the Edinger-Westphal nucleus at E7, E8, E9, and E10 was significantly higher than at E12. The early appearance of agrin mRNA coincides with the period during which acetylcholine receptors are being organized on ciliary ganglion neurons, consistent with the possibility that agrin contributes to neuron-neuron synapse formation in this pathway.

Agrin↗