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B Faivre

Publications and source records attributed to B Faivre.

41 records · Page 3Linked to original sources
PubMed1988

[Green hair: clinical, chemical and epidemiologic study. Apropos of a case].

A 36-year-old blond woman suddenly developed green tinted hair following exposure to swimming pool water. This was the first green discoloration she noticed, although she had been an active swimmer for several years. Clinical examination showed green tinting toward the distal ends of the most superficial strands of hair. The copper content of plucked green hair measured by atomic absorption was elevated to 3,900 ppm and the copper concentration in water from the swimming pool implicated was 9.94 ppm. Following renewal, the latter value decreased to 107 ppb. Hair examination under polarizing light was normal, and a scanning electronmicroscopic study of hair samples showed a total loss of cuticle with micropits scattered over the hair shaft surface mimicking a "dead tree trunk". Epidemiological investigations showed that the increased copper content of swimming pool water was due to added algaecides without adequate replacement of the water. Hair damage resulting from repeated waving and/or bleaching of the hair turns out to be an important factor in the deposition of copper by inducing an increase in keratin content of cysteic acid and related anionic sulfonate groups which participate in copper adsorption. On the ocassion of this case-report, epidemiological data published by others, together with the chemical and therapeutic aspects of green hair are reviewed.

Adult↗
PubMed1987

In vitro and in vivo study of an antimicrobial activity displayed by the redmouth disease agent, Yersinia ruckeri.

A soluble antimicrobial product has been detected in Yersinia ruckeri cultures. The contract droplets technique and the double agar layer method allowed to assess its bacteriostatic effect and the high susceptibility of other bacterial fish pathogens like Vibrio and Aeromonas. But it did not inhibit other strains of Y ruckeri. No correlation was found between the antimicrobial activity and the virulence of the strains. As mixed infections with A salmonicida and Y ruckeri could be obtained experimentally, the factor does not seem to confer any competitive advantage in fish tissues colonization.

Animals↗
PubMedDate not supplied

[Relationship between arterial pressure evolution and free hemoglobin distribution into vascular wall in guinea pigs].

Free hemoglobin (Hb) present at high concentration in plasma--in case of hemolysis, hemoglobin based oxygen carrier (HBOC) administration or in case of subarachnoid hemorrhage--induce hypertension as result of vasoconstriction. In this context, we studied on an exchange transfusion (ET) model at 50% of hematocrit with a HBOC, the distribution of this Hb inside abdominal aortic wall in guinea pigs in relation with mean arterial pressure (MAP) evolution. MAP was monitored during 180 min after ET and rings of abdominal aorta were taken at different times, when modifications of MAP were important, and analyzed by immunohistochemistry and confocal microscopy. Gelofusine 4%, used as control, did not modify MAP while free Hb increased MAP that reached its maximum (53% of hypertension) at t=17 min after the end of ET. MAP started to decrease (45% of hypertension) at t =60 min after ET, and recovered its baseline value at t=180 min. Confocal analysis of the vessel showed that: at 17 min (when hypertension was maximal), free Hb was present in endothelial cells (EC) and in vasa vasorum; at t=60 min (when hypertension decreased) and at t =10 min (when hypertension disappeared), free Hb was detected still in EC, but inside all abdominal aorta wall too. These results suggest in the first time that free Hb could induce a hypertension by direct interaction with EC but would also be unable to maintain this hypertension in spite of its massive tissue distribution.

Animals↗
PubMedDate not supplied

[Potential mechanism of dextran-conjugated hemoglobin penetration inside arterial wall].

Several reports indicated that cell-free hemoglobin induced vasoconstriction. This phenomenon was due to different pharmacological (NO trapping, vasoactive agents release and endothelial uptake...) and physical (viscosity and oxidative process of cell-free hemoglobin...) factors. We have previously showed that the blood pressure increase would be due to the presence of Dex-BTC-Hb inside arterial wall. However, we do not know how hemoglobin penetrate inside arterial wall. The objective of this study was to examine the new hypothesis of hemoglobin penetration inside arterial wall dependent of endocytosis. For this reason, an endocytosis inhibitor, cytochalasin D, was tested. We measured in anesthetized guinea pigs, the evolution of mean arterial pressure (MAP) and plasma hemoglobin concentration in presence or absence of cytochalasin D (1.6 x 10(-4) M). These measurements were carried out before and after 50% isovolemic exchange transfusion (IET) with two cell-free hemoglobins: Dex-BTC-Hb (300 kDa) and stroma-free hemoglobin (64.5 kDa). The administration of Dex-BTC-Hb or stroma-free hemoglobin induced an immediate increase in MAP that peaked within 17 min after IET and returned to baseline after 120 min. cytochalasin D attenuated the elevation of MAP when administrated before Dex-BTC-Hb but not when administrated before stroma-free hemoglobin. Furthermore, without cytochalasin D, plasma hemoglobin concentration after Dex-BTC-Hb or stroma-free hemoglobin administration decreased significantly 120 min after IET. In presence of cytochalasin D, plasma hemoglobin concentration stayed constant in Dex-BTC-Hb-treated animals but not in stroma-free hemoglobin-treated animals. cytochalasin D inhibits the endocytosis in case of Dex-BTC-Hb but not in case of stroma-free hemoglobin. This would be due to the molecular weight of cell-free hemoglobin. Based on these data, we suggest that endocytosis is one of the mechanisms by which cell-free hemoglobin with high molecular weight penetrated inside vascular endothelial cells. This endocytosis would have an impact on induced hypertension.

Animals↗