Coenzyme Q10 deficiency and response to supplementation in pediatric and adolescent migraine

BACKGROUND: Coenzyme Q10 (CoQ10) has been suggested to be effective in the prevention of migraine, and levels can be quantified with standardized reference ranges. OBJECTIVE: This study documents the prevalence of CoQ10 deficiency in migraine headache and examines the potential effectiveness of supplementation. METHODS: We assessed patients attending a tertiary care center with frequent headaches for CoQ10 deficiency. We recommended patients with low CoQ10 levels begin supplementation with CoQ10 as part of their multidisciplinary treatment plan. We assessed response to treatment including correction of CoQ10 deficiency, overall headache improvement, and headache disability. RESULTS: CoQ10 was measured in 1550 patients (mean age 13.3 +/- 3.5, range 3 to 22 years). The mean total CoQ10 level was 0.60 +/- 0.20 microg/mL (range 0.21 to 1.77 microg/mL). Of these patients, 32.9% were below the reference range. Patients with low CoQ10 were recommended to start 1 to 3 mg/kg per day of CoQ10 in liquid gel capsule formulation. In a subset of patients who returned for timely follow-up (mean, 97 days), the total CoQ10 level improved to 1.20 +/- 0.59 microg/mL (P < .0001), while the headache frequency improved from 19.2 +/- 10.0 to 12.5 +/- 10.8 (P < .001) and headache disability assessed with PedMIDAS improved from 47.4 +/- 50.6 to 22.8 +/- 30.6 (P < .001). CONCLUSIONS: Deficiency of CoQ10 may be common in pediatric and adolescent migraine. Determination of deficiency and consequent supplementation may result in clinical improvement. Further analysis involving more scientifically rigorous methodology will be required to confirm this observation.     

"Stem cell" origin of the hematopoietic defect in dyskeratosis congenita

We have used the long-term bone marrow culture (LTBMC) system to analyze hematopoiesis in three patients with dyskeratosis congenita (DC), two of whom had aplastic anemia, and the third had a normal blood count (apart from mild macrocytosis) and normal BM cellularity. Hematopoiesis was severely defective in all three patients, as measured by a low incidence of colony-forming cells and a low level of hematopoiesis in LTBMC. The function of the marrow stroma was normal in its ability to support the growth of hematopoietic progenitors from normal marrows seeded onto them in all three cases, but the generation of hematopoietic progenitors from patients marrow cells inoculated onto normal stromas was reduced, thus suggesting the defect to be of stem cell origin. The parents and unaffected brother of one of the families have also been studied in LTBMC and all showed normal hematopoietic and stromal cell function. From this study we speculate that there are some similarities between DC and the defect in the W/Wv mouse.     

Etoposide causes illegitimate V(D)J recombination in human lymphoid leukemic cells

Etoposide is one of the most widely used antineoplastics. Unfortunately, the same treatment schedules associated with impressive efficacy are associated with an increased risk of secondary acute myeloid leukemia (AML), which has prompted its withdrawal from some treatment regimens, thereby potentially compromising efficacy against the original tumor. Because etoposide-associated AML is characterized by site-specific illegitimate DNA recombination, we studied whether etoposide could directly cause site-specific deletions of exons 2 and 3 in the hprt gene. Human lymphoid CCRF-CEM cells were treated with etoposide for 4 hours, and DNA was isolated after subculturing. The deletion of exons 2 and 3 from hprt was assayed by a quantitative polymerase chain reaction (PCR) method. In the absence of etoposide treatment, the frequency of deletions of exons 2 and 3 was very low (5.05 x 10(-8)). After exposure to 10 mumol/ L etoposide, the frequency of the exon 2 + 3 deletion was increased immediately after and at 24 hours after etoposide treatment (65 to 89 x 10(-8)) and increased to higher levels (128 to 173 x 10(-8)) after 2 and 6 days of subculture (P < .001 overall). The frequency of the exon 2 + 3 deletion assessed at 6 days of subculture after 4 hours of 0, 0.25, 1, 2.5, 5, and 10 mumol/L etoposide treatment increased with etoposide concentration, ie, 5.05 x 10(-8), 89.2 x 10(-8), 108 x 10(-8), 142 x 10(-8), 163 x 10(-8), and 173 x 10(-8), respectively (P < .0001). Sequencing of a subset of amplified products confirmed the presence of DNA sequences at the breakpoints consistent with V(D)J recombination. By contrast, exon 2 + 3 deletions after etoposide treatment in the myeloid cell lines KG-1A and K562 showed no evidence of V(D)J recombinase in their genesis. We conclude that etoposide can induce the illegitimate site-specific action of V(D)J recombinase on an unnatural DNA substrate after a single treatment in human lymphoid cells.     

Spatial Arrangement of Ribosomal Proteins: Reaction of the Escherichia coli 30S Subunit with bis-Imidoesters

The 30S ribosomal subunit of E. coli was treated with the bifunctional reagent bis-(methyl)suberimidate. Crosslinked ribosomal proteins were identified as bands with increased molecular weight after electrophoresis in polyacrylamide gels containing sodium dodecyl sulphate. The pattern of crosslinked products was altered when unfolded subunits were used. Free ribosomal protein was not crosslinked. Several of the crosslinked products were cleaved by ammonolysis to form the original monomeric protein constituents. The low yields of the reactions necessitated the use of radioactive proteins and auto-radiographic procedures. The crosslinked proteins were tentatively identified by coelectrophoresis of the radioactive ammonolysis products with carrier 30S protein in sodium dodecyl sulphate, and coelectrophoresis at pH 4.5 in buffers containing urea.     

Molecular cloning of cDNA for Avena phytochrome

We have isolated several cDNA clones for phytochrome, a plant regulatory photoreceptor. A cDNA library was constructed by using etiolated Avena poly(A)⁺ RNA enriched for phytochrome mRNA by size fractionation. Replicate arrays of colonies were differentially screened with cDNA probes made from poly(A)⁺ RNA that had been either enriched in or depleted of phytochrome mRNA. Of the colonies hybridizing preferentially with the enriched probe, several contained plasmids that specifically selected phytochrome mRNA when assayed by hybridization-selection and translation. The largest such plasmid, pAP-2, was used to isolate clones from an Avena genomic library. One of these genomic clones was then used to screen a second cDNA library in an attempt to identify full-length phytochrome clones. The largest of the plasmids thus obtained, pAP-3, contains a 3.4-kilobasepair (kbp) insert, verified to contain phytochrome sequences by hybridization-selection and translation. Sequence analysis of pAP-2 and pAP-3 revealed that the two clones are identical in sequence through a 2.4-kbp region in which they overlap. However, the pAP-2 insert contains, in addition, 1.5 kbp of sequence of unknown origin, the apparent result of a recombination event. Blots of poly(A)⁺ RNA hybridized with ³²P-labeled pAP-2 or pAP-3 show a single mRNA band at 4.2 kilobases. Blot analysis of RNA from dark-grown and from red-irradiated tissue demonstrates that a previously reported light-induced decrease in translatable phytochrome mRNA results from a decrease in physical abundance of this mRNA.