[The myth of virgin cleansing: Latest news on an archaic magico-religious practice]. / Le mythe du nettoyage par les vierges : actualité d'un archaïsme magico-religieux.

BACKGROUND: In the medical anthropology section of the Nanterre Hospital (France) for migrants and refugees, three cases were recorded of "virgin cleansing" in sub-Saharan African countries. PATIENTS AND METHODS: These consisted of sexual assaults (2 instances of rape and 1 of sexual interference) on sexually immature females (young girls) by patients with sexually transmitted infections (mainly HIV, syphilis) hoping they might thereby be cured. DISCUSSION: These particularly atrocious hetero-aggressive sexual practices based on magical arguments are unfortunately universal and are not limited to a specific culture. At the medical anthropology level, the belief in cleansing by virgins is based on the notion that the patient is dirty and impure. In the same way that emetics and/or laxatives are prescribed in the case of intestinal disorders (to "eliminate" the disease), some subjects use diuretics for urinary abnormalities or, literally, "clean vaginas (or anuses)" to purge their own miasma. The rising tide of population migrations (some of whom carry chronic infections), refugee camps, prolonged incarcerations, etc., makes observations of such phenomena increasingly frequent. Belief in cleansing by virgins (and the fatal consequences thereof) will be difficult to eradicate. The education of populations and health professionals should promote absolute respect for the body of children, and, more generally, of others, particularly since at this time of increasingly marked migratory flows, this problem sadly risks becoming widespread.

["Palimpsest scar" lesions in a context of torture (Darfur, Sudan)]. / Cicatrices « palimpsestes ¼ en contexte de torture (Darfour, Soudan).

BACKGROUND: As a result of the current exponentially growing refugee population from the Middle-East and East Africa (Sudan, Darfur, Eritrea), clinicians (including forensic pathologists) are seeing atypical skin lesions, mainly of a traumatic nature, but in some cases associated with long-standing lesions related to ethnic practices. PATIENTS AND METHODS: A case of torture sequelae is presented herein in a patient originally from Darfur (Sudan): cutaneous incisions were made on old scars several times using a knife. DISCUSSION: The clinical presentation of scarification lesions and that of atypically healed wounds (presumably an effect of inflammation induced by the introduction of irritating foreign bodies such as sand, salt, etc.) are completely different: in all cases they indicate a relative timeframe of the facts, which the clinician should not overlook in reconstructing the patient's course and the injuries to which he has been subjected (hence the proposed designation of "palimpsest scar", in the sense that a palimpsest is a manuscript on a parchment that previously contained writing but has been scratched clean to be overwritten). Thus, a "palimpsest scar" constitutes a fresh scar on top of and hiding another (ritual) scar in a context of ethnic cleansing. The diagnostic and clinical significance comes from the importance of differentiating between ethnic-type lesions and those induced by physical violence and abuse in a context of war.

Functionality of the three-site ferroxidase center of Escherichia coli bacterial ferritin (EcFtnA).

At least three ferritins are found in the bacterium Escherichia coli : the heme-containing bacterioferritin (EcBFR) and two nonheme bacterial ferritins (EcFtnA and EcFtnB). In addition to the conserved A and B sites of the diiron ferroxidase center, EcFtnA has a third iron-binding site (the C site) of unknown function that is nearby the diiron site. In the present work, the complex chemistry of iron oxidation and deposition in EcFtnA was further defined through a combination of oximetry, pH stat, stopped-flow and conventional kinetics, UV-vis, fluorescence, and EPR spectroscopic measurements on both the wild-type protein and site-directed variants of the A, B, and C sites. The data reveal that although H2O2 is a product of dioxygen reduction in EcFtnA and oxidation occurs with a stoichiometry of Fe(2+)/O2 ∼ 3:1 most of the H2O2 produced is consumed in subsequent reactions with a 2:1 Fe(2+)/H2O2 stoichiometry, thus suppressing hydroxyl-radical formation. Although the A and B sites are essential for rapid iron oxidation, the C site slows oxidation and suppresses iron turnover at the ferroxidase center. A tyrosyl radical, assigned to Tyr24 near the ferroxidase center, is formed during iron oxidation, and its possible significance to the function of the protein is discussed. Taken as a whole, the data indicate that there are multiple iron-oxidation pathways in EcFtnA with O2 and H2O2 as oxidants. Furthermore, our data do not support a universal mechanism for iron oxidation in all ferritins whereby the C site acts as transit site, as has been recently proposed.

Transferrins. Hen ovo-transferrin, interaction with bicarbonate and iron uptake.

Fe(III) uptake by the iron-delivery and iron-scavenging protein, hen ovotransferrin has been investigated in vitro between pH 6.5 and 9. In the absence of any ferric chelate, apo-ovotransferrin loses two protons with K1a = 50 +/- 1 nM and K2a = 4.0 +/- 0.1 nM. These acid-base equilibria are independent of the interaction of the protein with bicarbonate. The interaction with bicarbonate occurs with two different affinity constants, KC = 9.95 +/- 0.15 mM and KN = 110 +/- 10 mM. FeNAc3 exchanges its Fe(III) with the C-site of the protein in interaction with bicarbonate, direct rate constants k1 = 650 +/- 25 M-1 s-1, reverse rate constant k-1 = (6.0 +/- 0.1) x 10(3) M-1 s-1 and equilibrium constant K1 = 0.11 +/- 0.01. This iron-protein intermediate loses then a single proton, K3a = 3.50 +/- 0.35 nM, and undergoes a first change in conformation followed by a two or three proton loss, first order rate constant k2 = 0.30 +/- 0.01 s-1. This induces a new modification in conformation followed by the loss of one or two protons, first order rate constant k3 = (1.50 +/- 0.05) x 10(-2) s-1. These modifications in the monoferric protein conformation are essential for iron uptake by the N-site of the protein. In the last step, the monoferric and diferric proteins attain their final state of equilibrium in about 15,000 s. The overall mechanism of iron uptake by ovotransferrin is similar but not identical to those of serum transferrin and lactoferrin. The rates involved are, however, closer to lactoferrin than serum transferrin, whereas the affinities for Fe(III) are lower than those of serum transferrin and lactoferrin. Does this imply that the metabolic function transferrins is more related to kinetics than to thermodynamics?

Is hydrogen peroxide produced during iron(II) oxidation in mammalian apoferritins?

The ferritins are a class of iron storage and detoxification proteins that play a central role in the biological management of iron. These proteins have a catalytic site, "the ferroxidase site", located on the H-type subunit that facilitates the oxidation of Fe(II) to Fe(III) by O(2). Measurements during the past 10 years on a number of vertebrate ferritins have provided evidence that H(2)O(2) is produced at this diiron ferroxidase site. Recently reported experiments using three different analytical methods with horse spleen ferritin (HoSF) have failed to detect H(2)O(2) production in this protein [Lindsay, S., Brosnahan, D., and Watt, G. D. (2001) Biochemistry 40, 3340-3347]. These findings contrast with earlier results reporting H(2)O(2) production in HoSF [Xu, B., and Chasteen, N. D. (1991) J. Biol. Chem. 266, 19965-19970]. Here a sensitive fluorescence assay and an assay based on O(2) evolution in the presence of catalase were used to demonstrate that H(2)O(2) is produced in HoSF as previously reported. However, because of the relatively few H-chain ferroxidase sites in HoSF and the reaction of H(2)O(2) with the protein, H(2)O(2) is more difficult to detect in this ferritin than in recombinant human H-chain ferritin (HuHF). The proper sequence of addition of reagents is important for measurement of the total amount of H(2)O(2) produced during the ferroxidation reaction.