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Biomedical subjects

J Petithory

Publications and source records attributed to J Petithory.

At least 19 recordsLinked to original sources

[Encephalopathy and memory disorders during treatments with mefloquine].

Benign psychiatric side effects have been frequently associated with mefloquine therapy. On the other hand, severe psychiatric disorders due to mefloquine are rare but must be detected by physicians. Two such cases are reported. In the first case, excessive curative mefloquine therapy caused an acute psychotic state which ultimately regress without treatment. The second report concerns a transient memory failure following prophylactic mefloquine treatment. The causative role of this compound is being discussed and the importance of a differential diagnosis of neuropsychiatric disorders from toxic or parasitic origin is underlined. Circumstances aggravating such neuropsychiatric side effects and actual recommendations concerning the prescription of mefloquine are recalled.

Adult↗

[First case of human toxocariasis (?) with adult worms in the circulatory system, detected by the presence of embryonated eggs in hemolysis concentration].

Ascarids's eggs were found by blood concentration in a Cameroonese patient with hypereosinophilia. Eggs, similar to those of Toxocara canis or cati, were present in 6 blood concentrations carried out during 7 weeks. These eggs (70-75 x 100-112 microns) contained embryos and hatching of 437-504 microns long larvae was sometimes observed. The presence of adult worms in a well oxygenated localization (e.g.; the left ventricle) was supposed. A pleural effusion was also observed but the low number of eosinophils in the pleural fluid (3%) eliminated the responsibility of the parasite. The treatment by thiabendazole for an associated strongyloidosis was well tolerated but inefficient. On the contrary, the treatment by diethylcarbamazine, well tolerated, induced the disparition of the circulating eggs. This result was confirmed by 6 blood concentrations carried out during 6 months.

Adult↗

Reconstitution of periplasmic transport in inside-out membrane vesicles. Energization by ATP.

The periplasmic histidine permease of Salmonella typhimurium has been reconstituted in inside-out vesicles (IOV) of Escherichia coli by disrupting the cells with a French press in the presence of a high concentration of the periplasmic histidine-binding protein, HisJ. Efflux from IOV, which is equivalent to uptake in whole cells, is induced by ATP. The reconstituted system depends on the presence of the membrane-bound permease proteins, HisQ, HisM, and HisP, and does not function if reconstitution is performed in the presence of a mutant HisJ protein, HisJ5625, that can bind histidine normally but can't interact properly with the membrane complex. Efflux is not induced by the nonhydrolyzable ATP analog, adenyl-5'-yl imidodiphosphate, supporting the contention that ATP hydrolysis is necessary. 8-Azido ATP inactivates IOV, indicating that the ATP effect occurs through the HisP protein, which has previously been shown to be modified by 8-azido ATP (Hobson, A., Weatherwax, R., and Ames, G.F.-L. (1984) Proc. Natl. Acad. Sci. U. S. A. 81, 733-7337). The estimated Km of the vesicles for ATP is about 200 microM. Vanadate, an inhibitor of phosphohydrolase enzymes, inhibits ATP-induced efflux. We conclude that ATP is likely to be the proximal energy source for periplasmic permeases.

Adenosine Triphosphate↗

Spacing mutations between the Escherichia coli pBAD RNA polymerase binding site and the araC (I) induction site.

Mutations in the Escherichia coli promoter PBAD have been constructed which alter the spacing of the adjacent RNA polymerase and araC inducer protein binding sites. While deletion of a single base-pair or small insertions do not detectably affect araC protein binding to DNA and they do not alter the conserved sequence of the RNA polymerase binding site, stimulation of PBAD in vivo is greatly reduced. The experiments suggest that the distance or angle between the two proteins on the DNA is critical for promoter function.

AraC Transcription Factor↗

[ELISA in schistosomiasis. Limits. Possibility of application (author's transl)].

Sera from patients with schistosomiasis and various infections were examined by an enzyme-linked immunosorbant assay technique (ELISA) using soluble antigens prepared from adult worms and eggs of Schistosoma mansoni. Marked false positive reactions were observed in cases of certain parasitic (hydatidosis) and non parasitic diseases (liver cirrhosis). Equivalent results with the techniques of immunofluorescence and immunoenzymology (done on adult sections) were obtained with adult worm antigen read at a higher optic-density limit. At present, this technique might be useful in seroepidemiological surveys; however, further purification of the antigen will increase its sensibility and specificity.

Echinococcosis↗

[A probable laboratory contamination with Plasmodium falciparum].

A student working in a medical biology department presented a severe Plasmodium falciparum malaria, with high thrombopenia, hypercalcemia and hypophosphoremia. The mode of infection seems to be a laboratory contamination with a highly contaminated blood sample through skin excoriations.

Adult↗