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Cross-correctional studies in inborn errors of vitamin B12 metabolism

Human skin fibroblasts derived from patients with all 7 known inborn errors of vitamin B$ sb{12}$ metabolism have been studied for functional integrity of methylmalonyl CoA mutase and methionine synthase. Cocultivation of cblC and cblF fibroblasts in the absence of polyethylene glycol resulted in a twofold increase over the expected in both ($ sp{14}$C) propionate and ($ sp{14}$C) methyltetrahydrofolate incorporation into acid-precipitable material, suggesting that metabolic cooperation between cells occurs. CblD fibroblasts, which are biochemically similar to cblC cells (Goodman et al, 1970; Willard et al, 1977), do not cooperate metabolically when mixed with cblF cells. Partial correction in phenotype was seen in mixtures of cblD and cblG cells, but not cblC and cblG cells. These observations lend further support for the division of cblC and cblD disease into two discrete complementation classes. Cocultivation of cblF fibroblasts with both cblE and cblG cells also resulted in partial correction in phenotype. / ($ sp{14}$C) Propionate incorporation in both cblC and cblF cells exposed to conditioned medium from control cells was increased more than twofold. ($ sp{14}$C) methyltetrahydrofolate incorporation in cblC cells exposed to conditioned medium from cblF cells was increased twofold. This suggests the presence of a diffusible factor correcting the defect in the mutant cell lines.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.59259
Date January 1989
CreatorsByck, Susan
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Science (Department of Biology.)
RightsAll items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated.
Relationalephsysno: 001067865, proquestno: AAIMM63450, Theses scanned by UMI/ProQuest.

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