Contribution to the Data on Copper Concentration in Blood and Urine in Patients with Wilson’s Disease and in Normal Subjects

Determination of copper in human tissues and body fluids may be crucial in the diagnosis of Wilson’s disease. In this study we evaluated urinary copper excretion and urine and blood concentration in 14 patients in whom Wilson’s disease was confirmed (group A) and in 21 subjects in whom the disease was only suspected (group B). The following values (mean ± SD) were found: 24-h urine (μg Cu/24 h), 152 ± 135 (A) and 31.8 ± 10.9 (B); urine (μg Cu/ml), 0.091 ± 0.087 (A) and 0.028 ± 0.011 (B); and blood (μg Cu/ml), 0.62 ± 0.25 (A) and 0.72 ± 0.09 (B). By comparison, urine copper concentration in the group of apparently healthy subjects was 0.035 ± 0.010 (n = 50), and blood copper concentration in autopsy cases of nonpoisoned people was 0.85 ± 0.19 (n = 73).     

Reply to the Comment by S. Harvey on “Entropy,Energy, and Bending of DNA in Viral Capsids”

The comment by Stephen Harvey in this issue of the Biophysical Journal concludes with two statements regarding my recent letter about DNA packaging into viral capsids. Harvey agrees with my interpretation of the origin of the large confinement entropy predicted by the molecular-dynamics simulations of his group, and its sensitive dependence on the molecular parameters of their wormlike chain model of double-stranded DNA. On the other hand, he doubts my assertion that the confinement entropy is already included in the interstrand repulsion free energy derived from osmotic stress measurements, which constitutes the major contribution to the packaging free energy used in recent continuum theories of this process. Harvey suggests instead that the confinement entropy should be added to this free energy as a separate term (using, for instance, the method described in my letter). I will argue that this addition is redundant, and, in a brief discussion of continuum theories, will also discuss his comments as relates to the work of other researchers.     

Effects of Mother’s Illness and Breastfeeding on Risk of Ebola Virus Disease in a Cohort of Very Young Children

Background

Young children who contract Ebola Virus Disease (EVD) have a high case fatality rate, but their sources of infection and the role of breastfeeding are unclear.

Methods/Principal Findings

Household members of EVD survivors from the Kerry Town Ebola Treatment Centre in Sierra Leone were interviewed four to 10 months after discharge to establish exposure levels for all members of the household, whether or not they became ill, and including those who died. We analysed a cohort of children under three years to examine associations between maternal illness, survival and breastfeeding, and the child’s outcome. Of 77 children aged zero to two years in the households we surveyed, 43% contracted EVD. 64 children and mothers could be linked: 25/40 (63%) of those whose mother had EVD developed EVD, compared to 2/24 (8%) whose mother did not have EVD, relative risk adjusted for age, sex and other exposures (aRR) 7·6, 95%CI 2·0–29·1. Among those with mothers with EVD, the risk of EVD in the child was higher if the mother died (aRR 1·5, 0·99–2·4), but there was no increased risk associated with breast-feeding (aRR 0·75, 0·46–1·2). Excluding those breastfed by infected mothers, half (11/22) of the children with direct contact with EVD cases with wet symptoms (diarrhoea, vomiting or haemorrhage) remained well.

Conclusion/Significance

This is the largest study of mother-child pairs with EVD to date, and the first attempt at assessing excess risk from breastfeeding. For young children the key exposure associated with contracting EVD was mother’s illness with EVD, with a higher risk if the mother died. Breast feeding did not confer any additional risk in this study but high risk from proximity to a sick mother supports WHO recommendations for separation. This study also found that many children did not become ill despite high exposures.     

Microscopical and Spectroscopic Studies on the Fluorescence of a Daunomycin–aluminum Complex

In this study, the spectroscopic features and microscopical applications of the fluorescent daunomycin-Al3+ complex have been analyzed. In the presence of Al3+, the absorption spectrum of daunomycin showed a deep bathochromic shift and new peaks at 529 and 566nm, whereas the fluorescence emission was considerably modified. The emission of daunomycin alone (peak at 560nm under optimal excitation at 470nm) decreased continuously from 0.5 to 24h after addition of Al3+ ions, and a new emission peak appeared at 580nm (optimal excitation at 530nm). Under the fluorescence microscope using green exciting light, nuclei from chicken blood smears and paraffin sections of rat embryos stained with daunomycin showed a weak emission, which greatly increased after treatment with Al3+ ions. The bright and stable fluorescence of chromatin DNA induced by daunomycin-Al3+ could be a valuable labelling method in fluorescence microscopy and DNA cytochemistry.     

Sorting and Processing of the Alzheimer’s Disease Amyloid Precursor Protein Mediated by the AP-4 Complex

Proteolytic processing of the transmembrane amyloid precursor protein (APP) to aggregation-prone amyloid-β (Aβ) peptide underlies the development of Alzheimer’s disease.     

Crystallographic studies of the binding of ligands to the dicarboxylate site of Complex II,and the identity of the ligand in the “oxaloacetate-inhibited” state

Mitochondrial Complex II (succinate:ubiquinone oxidoreductase) is purified in a partially inactivated state, which can be activated by removal of tightly bound oxaloacetate (E.B. Kearney, et al., Biochem. Biophys. Res. Commun. 49 1115–1121). We crystallized Complex II in the presence of oxaloacetate or with the endogenous inhibitor bound. The structure showed a ligand essentially identical to the “malate-like intermediate” found in Shewanella Flavocytochrome c crystallized with fumarate (P. Taylor, et al., Nat. Struct. Biol. 6 1108–1112) Crystallization of Complex II in the presence of excess fumarate also gave the malate-like intermediate or a mixture of that and fumarate at the active site. In order to more conveniently monitor the occupation state of the dicarboxylate site, we are developing a library of UV/Vis spectral effects induced by binding different ligands to the site. Treatment with fumarate results in rapid development of the fumarate difference spectrum and then a very slow conversion into a species spectrally similar to the OAA-liganded complex. Complex II is known to be capable of oxidizing malate to the enol form of oxaloacetate (Y.O. Belikova, et al., Biochim. Biophys. Acta 936 1–9). The observations above suggest it may also be capable of interconverting fumarate and malate. It may be useful for understanding the mechanism and regulation of the enzyme to identify the malate-like intermediate and its pathway of formation from oxaloacetate or fumarate.