Quality of life in children suffering from headaches: a systematic literature review.

BACKGROUND: Headaches are the most common complaints among pediatric populations. Determining the cause and appropriate treatment for headaches may be challenging and costly, and the impact of headaches on the lives of patients and their families is not well understood. OBJECTIVE: A systematic literature review was conducted to examine what PROMs are currently used, and to identify quality of life (QoL) concepts important to children suffering from headaches and any known determinants of QoL. METHODS: Embase, Medline, Web of Science, CINAHL, EBSCOhost, PsychINFO, Cochrane CENTRAL and Google Scholar were searched from their inception through to June 2021. Studies investigating QoL, using a validated outcome measure in pediatric patients with headaches, were included. Relevant studies were identified through title and abstract screening and full text review by two independent reviewers. A citation review of included studies was performed. QoL concepts were extracted from the outcome measures that were used in each study to develop a preliminary conceptual model of QoL in children suffering from headaches. Determinants of QoL were also identified and categorized. RESULTS: A total of 5421 studies were identified in the search. Title and abstract screening resulted in the exclusion of 5006 studies. Among the 415 studies included for full text review, 56 were eligible for final analysis. A citation review resulted in the addition of five studies. Most studies were conducted in high-income countries and included a patient-sample accordingly (n = 45 studies). Sixteen different PROMs were identified in the included studies, of which the PedsQL was used the most often (n = 38 studies). The most common health concepts reported were physical functioning (n = 113 items), social and psychological wellbeing (N = 117, n = 91 resp.). Twenty-five unique determinants of QoL were extracted from the included studies. CONCLUSION: There is a need for a condition-specific PROM to facilitate the measurement of QoL outcomes in the pediatric headache population. A conceptual model was developed based on the findings from the health concepts. Findings from this review could be used for future qualitative interviews with pediatric patients with headaches to elicit and refine important QoL concepts.

BCS-like density of states in superconducting A3C60 surfaces

We report on an ultrahigh resolution photoemission study on the topmost molecular layer of K3C60 and Rb3C60 films below and above the superconducting transition temperature T(C). We observed not only clear evidence for the opening of the superconducting gap, but also a modification in the photoemission line shape consistent with a change from a normal-metallic to a BCS-like density of states, including the formation of a condensation peak. The data can be accurately modeled by a BCS-type function with a gap Delta derived from T(C) in the weak-coupling limit ( 2Delta/k(B)T(C) = 3.53).

Sulfhydryl compounds influence immunoreactivity, structure and functional aspects of lipoprotein(a).

Human plasma Lp(a) is susceptible to various sulfhydryl compounds. In this study we present evidence indicating that after treatment of Lp(a) with sulfhydryl compounds, immunoreactivity is changed, structural changes occur and functional characteristics regarding the numerous kringle structures in apo(a) disappear. Purified Lp(a) was subjected to variable concentrations (0.01-10 mM) of various sulfhydryl compounds: DTT, 2-mercapto-ethanol (BME), N-acetylcysteine (NAC) and homocysteine (HCys). Free SH groups were blocked by iodoacetamide. Reduced and alkylated Lp(a) was tested in two ELISAs, one detecting apo(a) alone and one detecting apo(a)-apoB complexes. In both ELISAs polyclonal antibodies were used. For comparison a commercial apo(a) IRMA utilizing two monoclonal antibodies was used. The results indicate that a similar decrease in response of both ELISAs is observed, whereas the IRMA response is less affected. Western blotting of "DTT treated" Lp(a) after SDS-PAGE under nonreducing conditions showed that separate apo(a) and apoB-100 bands became detectable at 1 mM DTT. Native PAGE (2.5-16%) indicated structural changes of Lp(a) beginning to occur at 0.03 mM DTT. Epsilon-aminocaproic acid-inhibitable binding of "DTT-treated" Lp(a) to Desafib-X decreased with increasing DTT concentrations in concert with a loss of the capacity of Lp(a) to inhibit plasminogen activation upon treatment with DTT. The observed immunological and functional changes of Lp(a) indicate that apo(a) kringle function is severely affected by sulfhydryl compounds.

Cross-linking of starch with bifunctional precursors of nitroalkenes.

Granular starch was cross-linked with 1,3-di-O-acetyl-2-nitro-1,3-propanediol (1), 1,3-di-O-pivaloyl-2-nitro-1,3-propanediol (2), 2-nitro-3-O-pivaloyl-1-propene-3-ol (3), 1,3-di-O-acetyl-aci-2-nitro-1, 3-propanediol (4), 1,3-di-O-pivaloyl-aci-2-nitro-1,3-propanediol (5) and 1,6-di-O-acetyl-2,5-dinitro-1,6-hexanediol (6). The bifunctional precursors for the nitro-alkenes 1, 2, 3, and 4 were readily synthesized in high yields from nitromethane, paraformaldehyde and acetic anhydride (1, 3) or pivaloyl chloride (2, 4), respectively. The reaction rate for the cross-linking was very high, and for 1 and 3, the reaction reached completion within 1 h (at room temperature). The swelling capacities of the products obtained when starch was cross-linked with precursors for the nitroalkenes 1-4 and 6 were lower in comparison to epichlorohydrin cross-linked starch. These results indicate a high reaction efficiency at low degrees of substitution. Cross-linked 2-nitroalkyl starch ethers were synthesized in a one-pot synthesis by addition of 1 or 3 and 2-nitroalkyl acetates to granular suspensions of starch.

Synthesis, analysis and reduction of 2-nitropropyl starch.

Granular 2-nitropropyl potato starch was synthesized by reaction with 2-nitropropyl acetate in an aqueous suspension. Nitroalkylation occurs preferentially with the amylose fraction of potato starch, as was confirmed by leaching experiments and digestion of the modified starch with alpha-amylase. The 2-nitropropyl substituent is a mixture of the nitroalkane and nitronic acid tautomer. Some grafting occurs and to a lesser extent additional reactions (formation of carbonyls and oximes) of the nitro group take place. After catalytic hydrogenation of water soluble 2-nitropropyl starch only a small amount of the nitro functionality was reduced to the corresponding amine. Reduction of granular 2-nitropropyl starch with sodium dithionite did not go to completion and led to a complex mixture of starting material, several intermediates and side products (for example sulfamates).