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Biomedical subjects

E Brunet

Publications and source records attributed to E Brunet.

29 records · Page 2Linked to original sources
PubMed1988

Preschool vision testing with a new device, the Scolatest.

To determine the reliability of results obtained in preschool children by school nurses with a new device for testing vision, the Scolatest, 153 children aged 4 to 5 years were presented with the Snellen E on the standard American Optical projector and with five letters of the Sheridan test (H, O, V, T and X) on the Scolatest. Another 212 children aged 3 to 4 years were presented with the Allen symbols on the projector and with the Pigassou symbols on the Scolatest. The tests with the projector were given at 6 m by an experienced pediatric orthoptist, those with the Scolatest at 2.5 m by a school nurse. The proportion of good responses was higher with the Pigassou symbols than with the Allen symbols. The results with the Sheridan letters and the Snellen E were similar up to 20/30; beyond 20/30 the Snellen E appeared unreliable. The four vision-testing systems were also presented by a school nurse at 2.5 m on the Scolatest to 102 children aged 4 to 5 years (Snellen E and the five Sheridan letters) and 80 children aged 3 to 4 years (Allen and Pigassou symbols). The proportions of good responses were more comparable. The results suggest that a working distance of 2.5 m should be used in testing vision in preschool children. Visual screening at this distance should test acuity beyond the 20/30 equivalence if results comparable to those at 20 feet with the 20/30 standard requirement are to be obtained.

Child, Preschool↗
PubMed1986

In vivo time course of synthesis and processing of major schizont membrane polypeptides in Plasmodium falciparum.

A rapid method of separating membrane co-sedimentable and soluble components of Plasmodium infected erythrocytes is presented. We propose a nomenclature for major P. falciparum polypeptides, applicable to different isolates and based on their cellular location and stage specificity. For four of these polypeptides (185 kDa = Mp1; 120 kDa = Mp3; 76 kDa = Mp5; 90 kDa= Sp2) supposed to play a role in protective immunity, monospecific antibodies were available. We have studied their fate at the time of merozoïte release and reinvasion, and the possible correlations between these polypeptides, by pulse-chase experiments.

Animals↗
PubMed1984

Cloning of cDNAS that code for Plasmodium chabaudi antigens of the erythrocytic forms and cross-hybridize with P. falciparum.

Several Plasmodium chabaudi antigens are synthesized and the corresponding mRNAs are detected by cell-free translation only during specific stages of the erythrocytic cycle. Ring stage mRNA was used to construct a cDNA library in the plasmid vector pBR 322. The library was screened by differential hybridization with cDNA specific for ring stage parasites or schizonts. Two clones which showed some stage specificity and seven which did not were retained. Three clones were characterized by hybrid-selected translation. Clones 451, 148 and 443 contain sequences homologous to the messages for a 27 kDa stage-specific antigen, a 37 kDa early antigen and a 24 kDa antigen, respectively. The nine clones cross-hybridize to various degrees with cDNA from P. falciparum but cross hybridization intensities do not reflect the strength of immunological cross-reactivity.

Animals↗
PubMed1982

Destruction of Leishmania mexicana amazonensis amastigotes within macrophages in culture by phenazine methosulfate and other electron carriers.

Exposure of macrophages infected with Leishmania mexicana amazonensis to phenazine methosulfate (PMS) resulted in rapid damage and disappearance of the intracellular amastigotes without obvious ill effects to the host cells. The reduction of the percent infection was related to the concentration of PMS and to the duration of the pulse. Most Leishmania disappeared within 2 h of a 2-h pulse with 10 muM of the drug. In contrast, pretreatment of the macrophages with PMS followed by removal of the drug before infection did not result in disappearance of the parasites. The pH of the PMS medium markedly influenced the disappearance of Leishmania: maximum effect was observed at pH 8.0, while the effect was negligible at pH 6.3. The pH effect may be related to pseudobase formation by the PMS cation. Dose-response curves for PMS were similar for resident, elicited, or activated macrophages. Observations by time-lapse cinemicrography documented the explosion-like fragmentation of the amastigotes within 1-2 h of exposure of infected macrophages to the drug. Parasite-derived granules and vacuoles were seen to scatter within the parasitophorous vacuoles. This early damage to the parasites was confirmed by transmission electron microscopic observations. Infected macrophages incubated with PMS displayed detectable vacuolar fluorescence, indicating that PMS or a metabolite of PMS had access to the vacuoles. A series of other electron carriers, including phenyl methanes, phenazines, oxazines, a xanthene, and a naphthoquinone, given continuously for 18 h, also induced the disappearance of the Leishmania. The most potent was crystal violet, active at 70 nM. The presence of apolar substituents enhanced activity and this is probably related to increased permeation of the dyes. Finally, PMS, as well as other electron carriers examined, also reduced the growth of Leishmania promastigotes in culture. The results are compatible with a direct effect of the drugs on the intracellular amastigotes, involving only a permissive participation of the macrophages. We propose that the diverse agents destroy the amastigotes by redox-cycling generation of active oxygen metabolites at or near the parasites. Alternatively, the effect of the drugs could be mediated by toxic free radical reduction species of the drugs or by interference with electron flow or with the intermediary metabolism of Leishmania.

Animals↗
PubMed1980

Progressive-addition lenses in the management of esotropia with a high accommodation/convergence ratio.

In 25 children esotropia due to abnormal synkinesis between accommodation and accommodative convergence was corrected with progressive-addition lenses. Twelve of the children had been wearing conventional bifocals; the other 13 were given progressive lenses for the first time. The near esodeviation was satisfactorily neutralized in most cases, and nearly all the children had some stereopsis. All adapted well and without difficulty to the progressive lenses.

Accommodation, Ocular↗
PubMedDate not supplied

Luminescent cryptands. 3-aroylcoumarin macrobicyclic complexes of europium(III) and terbium(III): the effect of coumarin substitution.

Substituted 3-aroylcoumarins incorporated in a polyethylenoxy cryptand (2.2.2) by the 3-aroyl group were synthesized with the purpose of developing new markers to be used in time-resolved fluorimetric bioaffinity assays based on the unique luminescence properties of Eu(III) and Tb(III) ions. Some spectral properties and luminescence intensities of the complexes were measured in acetonitrile and MeOH. The mechanism of metal sensitization depended on lanthanide and will be discussed in detail.

Bridged Bicyclo Compounds, Heterocyclic↗