scholarly journals Lipoamide Dehydrogenase in Friedreich's Ataxia Fibroblasts

1978 ◽  
Vol 5 (1) ◽  
pp. 115-118 ◽  
Author(s):  
S. B. Melançon ◽  
M. Potier ◽  
L. Dallaire ◽  
G. Fontaine ◽  
B. Grenier ◽  
...  
Keyword(s):  
Subcellular Distribution ◽  
Specific Activity ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Skin Fibroblasts ◽  
Lipoamide Dehydrogenase ◽  
Normal Controls

SUMMARY:Lipoamide dehydrogenase was measued in cultivated skin fibroblasts from twelve patients with Friedreich's ataxia and nine normal controls. No difference in specific activity, subcellular distribution and Vmax or Km was observed between patients and controls.

scholarly journals Oral Lecithin and Linoleic Acid in Friedreich’s Ataxia: II. Clinical Results

1982 ◽  
Vol 9 (2) ◽  
pp. 155-164 ◽  
Author(s):  
S.B. Melancon ◽  
M. Vanasse ◽  
G. Geoffroy ◽  
L. Barabe ◽  
A. Proulx ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Clinical Performance ◽  
Stage Iv ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Safflower Oil ◽  
Therapeutic Trial ◽  
Mean Values ◽  
Significant Difference ◽  
Normal Controls

SUMMARY:Twenty-two patients with Friedreich’s Ataxia and ten normal controls were followed for one year and assessed as to their clinical performance after two successive six-month periods of lecithin or safflower oil. Results demonstrated no significant difference in performance scores according to group assignation, neither in patients nor in controls. According to stages, two patients in stage I and to a lesser degree, one patient in stage IV showed better scores for muscle strength and some motor accuracy and coordination tests with lecithin. Controls as groups maintained positive scores in all tests. Patients as groups showed negative mean values in nine out of eleven tests. Again as groups, patients receiving safflower oil demonstrated a mean 8% less deterioration than patients receiving lecithin. This study demonstrates that objective clinical tests and the participation of normal controls are a must in a therapeutic trial implicating patients with a progressive disorder such as Friedreich’s Ataxia. The possible role of linoleic acid as the active factor from which clinical improvement proceeded in some specific patients and with early functional stages of the disease, has to be considered and reevaluated in the near future.

scholarly journals Electrophysiological Investigation of the Auditory System in Friedreich’s Ataxia

1982 ◽  
Vol 9 (2) ◽  
pp. 131-135 ◽  
Author(s):  
M.J. Taylor ◽  
J.B. McMenamin ◽  
E. Andermann ◽  
G.V. Watters
Keyword(s):  
Auditory System ◽  
Friedreich’S Ataxia ◽  
Auditory Brainstem ◽  
Friedreich's Ataxia ◽  
The Other ◽  
Auditory Brainstem Responses ◽  
Evoked Responses ◽  
Electrophysiological Investigation ◽  
Auditory Evoked Responses ◽  
Normal Controls

ABSTRACT:Auditory brainstem responses (ABRs) and cortical auditory evoked responses (AERs) were studied in a series of 16 Friedreich’s ataxia patients who varied in age, degree of clinical involvement and duration of the disorder. The ABRs were markedly abnormal in all but the youngest patient, and the abnormalities reflected the severity and duration of the disease. The latencies of the AERs were significantly longer in the Friedreich’s ataxia patients compared to normal controls, suggesting cortical as well as peripheral involvement of the auditory system. These data are discussed in terms of the neuropathology of the disorder and the similarities with the other sensory systems in Friedreich’s ataxia patients.

scholarly journals Characterization of lysosomes and lysosomal enzymes from Chediak-Higashi-syndrome cultured fibroblasts

1986 ◽  
Vol 238 (2) ◽  
pp. 589-595 ◽  
Author(s):  
A L Miller ◽  
R Stein ◽  
M Sundsmo ◽  
R Y Yeh
Keyword(s):  
Lysosomal Enzymes ◽  
Specific Activity ◽  
Skin Fibroblasts ◽  
Cultured Fibroblasts ◽  
Cultured Skin ◽  
Lysosomal Dysfunction ◽  
Chediak Higashi Syndrome ◽  
Normal Controls

Chediak-Higashi-syndrome cultured skin fibroblasts were used to study the possible involvement of lysosomal enzymes and lysosomal dysfunction in this disorder. Our evidence indicated that Chediak-Higashi fibroblasts displayed a significant decrease in the specific activity of the acidic alpha-D-mannosidase (pH 4.2) compared with normal controls. Additional studies revealed a small, but significant, decrease in the rate of degradation of 125I-labelled beta-D-glucosidase that had been endocytosed into Chediak-Higashi cells.

scholarly journals Serum and Platelet Lipoamide Dehydrogenase in Friedreich's Ataxia

1978 ◽  
Vol 5 (1) ◽  
pp. 111-114 ◽  
Author(s):  
A. Filla ◽  
R. F. Butterworth ◽  
G. Geoffroy ◽  
B. Lemieux ◽  
A. Barbeau
Keyword(s):  
Standard Deviation ◽  
Normal Control ◽  
Pyruvate Dehydrogenase ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Control Subjects ◽  
Lipoamide Dehydrogenase

SUMMARY:Pyruvate dehydrogenase (PDH), α -keto gluturate dehydrogenase (α -KGDH) and lipoamide dehydrogenase (LAD) were measured in platelets of II patients with typical Friedreich's ataxia and 10 normal control subjects. Serum LAD was also evaluated in the same patients. No statistically significant changes were found in platelets for the group as a whole, although some patients had low values (more than one standard deviation below control mean). Serum LAD was significantly reduced in the patients with Friedreich's ataxia. This was not due to associated diabetes.

scholarly journals A Possible Genetic Pattern of Taurine Urinary Excretion in Friedreich’s Ataxia

1982 ◽  
Vol 9 (2) ◽  
pp. 209-215 ◽  
Author(s):  
A. Barbeau ◽  
F. Patenaude ◽  
G. Nadon ◽  
M. Charbonneau ◽  
T. Cloutier
Keyword(s):  
Urinary Excretion ◽  
Autosomal Recessive ◽  
Genetic Defect ◽  
High Capacity ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Uptake System ◽  
Genetic Pattern ◽  
Before And After ◽  
Normal Controls

SUMMARY:The taurine urinary excretion pattern, before and after an oral load of 250 mg taurine, was studied in normal control subjects and in patients with typical Friedreich’s ataxia. It was demonstrated that in both situations the ataxic patients fell within the sub-types of “intermediate” and “high taurine excretors”, while none were “low taurine excretors”. It was also demonstrated that the excretion of taurine after a load in the obligate heterozygotes parents of the ataxic patients was intermediate between normal controls and patients. It is postulated that patients with Friedreich’s Ataxia lack normal regulation of the high affinity-low capacity uptake system for taurine (the TH system) in the brush border of kidney tubules. The low affinity-high capacity uptake system in the same membranes (the TL system) appears to be normal in Friedreich’s patients. The normal allele could be called THN and the variant THF and this trait would be inherited in an autosomal recessive fashion if it is linked to the Freidreich phenotype. Whether this finding is or is not the basic genetic defect in Friedreich’s Ataxia will require more studies to clarify, but it is of interest to note that a similar pattern appears to be present in the fibroblasts of these patients.

scholarly journals Friedreich's Ataxia 1979: An Overview

1979 ◽  
Vol 6 (2) ◽  
pp. 311-319 ◽  
Author(s):  
A. Barbeau
Keyword(s):  
Linoleic Acid ◽  
Pyruvate Dehydrogenase ◽  
Phenotypic Expression ◽  
Clinical Work ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
High Density Lipoproteins ◽  
Cholesteryl Esters ◽  
Cooperative Study ◽  
Lipoamide Dehydrogenase

SummaryThis overview summarizes the investigations carried out during the second part of Phase Two of the Quebec Cooperative Study of Friedreich's Ataxia. These investigations outline in more details the fundamental role played by an abnormality in the fatty acid composition (deficient linoleic acid, 18:2) of the cholesterol esters of high density lipoproteins (HDL) in the phenotypic expression of the disease. They postulate a defective incorporation of linoleic acid to surface phos-phatidylcholine of chylomicrons and consequent relative and absolute decreases in lipoproteinprotein components because of overpacking with defective cholesteryl esters. Secondarily to these changes, the postulated lack of activation of the lipoamide dehydrogenase (LAD) of the pyruvate dehydrogenase (PDH) complex could result in slow pyruvate oxidation, glucose intolerance, deficient synthesis of acetylcholine, and depletion of glutamic and aspartic acid pools. In parallel, abnormal phosphatidyl-choline molecules could be incorporated to membranes, resulting in specific defects in some functions of these membranes, including transport of calcium and I or taurine and myelinization. The framework of an understanding of Friedreich's ataxia is now available, but much fundamental and clinical work remains to be done to fill in and prove each one of these postulated steps.

scholarly journals SERUM LIPOAMIDE DEHYDROGENASE IN FRIEDREICH'S ATAXIA

1977 ◽  
Vol 11 (4) ◽  
pp. 460-460 ◽  
Author(s):  
Serge B Melancon ◽  
Michel Potier ◽  
Louis Dallaire ◽  
Guy Geoffroy ◽  
Bernard Lemieux ◽  
...  
Keyword(s):  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Lipoamide Dehydrogenase

scholarly journals Friedreich's ataxia: malic enzyme activity in cellular fractions of cultured skin fibroblasts

1984 ◽  
Vol 11 (S4) ◽  
pp. 637-642 ◽  
Author(s):  
S.B. Melançon ◽  
R. Cloutier ◽  
M. Potier ◽  
L. Dallaire ◽  
M. Vanasse ◽  
...  
Keyword(s):  
Malic Enzyme ◽  
Genetic Defect ◽  
Mitochondrial Fraction ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Skin Fibroblasts ◽  
Cultured Skin ◽  
Dependent Activity ◽  
Malic Enzyme Activity ◽  
Mitochondrial Malic Enzyme

AbstractWe have measured the activity of malic enzyme NADP+ dependent in the nuclear, mitochondrial, lysosomal and cytosolic fractions of cultured skin fibroblasts from twelve patients with Friedreich's ataxia and nine control subjects. Hexosaminidase, cytochrome-C-oxidase, lactate dehydrogenase and malic enzyme NAD+ dependent were used as marker enzymes. The activity of malic enzyme NADP+ dependent was not significantly reduced in the mitochondrial fraction of patients with Friedreich's ataxia as compared with controls. When corrected for possible contamination between mitochondrial and cytosolic fractions, malic enzyme NADP+ dependent activity was still not significantly reduced in patients with Friedreich's ataxia. Unless critical methodological differences were overlooked in this or previously published studies, we conclude that mitochondrial malic enzyme deficiency is not the primary genetic defect underlying Friedreich's ataxia.

Sign in / Sign up

Export Citation Format

Share Document