Larval Gulf Coast ticks (Amblyomma maculatum) [Acari: Ixodidae] as host for Hepatozoon americanum [Apicomplexa: Adeleorina].

Laboratory-reared larval Gulf Coast ticks (GCTs) (Amblyomma maculatum) were exposed experimentally and found to acquire Hepatozoon americanum infection while feeding on parasitemic dogs. These ticks supported gamogonic and sporogonic development of the apicomplexan, and oocysts from newly molted nymphs were infectious for a dog. Other nymphs from this cohort that were allowed to feed on a blood-parasite naive sheep molted normally; the resulting adult ticks contained oocysts that were infectious for another dog. Merogonic development of H. americanum in the dogs and the resulting lesions/disease appeared similar, irrespective of whether infectious oocysts were derived from nymphal or adult ticks that acquired infection as larvae. In the system previously known, nymphal ticks acquire infection and adults harbor infective oocysts, which vertebrate hosts ingest. Given that larval A. maculatum can acquire infection and nymphs can harbor viable oocysts as demonstrated by this study, the potential variety of vertebrate hosts that can alternate with GCTs in maintaining an endemic cycle is considerably expanded.

Application to drug-food interactions of living cells as in vitro model expressing cytochrome P450 activity: enzyme inhibition by lemon juice.

Classical inhibitors of human cytochrome P450 3A4 activity, such as ketoconazol and quercetin, are tested to prove the efficiency of a new metabolisation model using living entire cells. Grapefruit juice is a well-known potent inhibitor of cytochrome P450 3A4 activity. With regard to the clinical relevance of grapefruit juice-drug interactions, an investigation of other common juices is undertaken with this in vitro model. The CYP3A4 activity is measured by the formation of the 6beta-hydroxytestosterone, which is quantified by an isocratic high performance liquid chromatography. It is demonstrated for the first time that lemon juice significantly inhibits by 60+/-3% the CYP3A4-mediated oxidation. Grapefruit juice inhibits this activity by 82+/-4%. The mechanism of lemon juice inhibition is competitive, whereas it is mixed for grapefruit juice. These results suggest that our in vitro model combined with our analytical method is applicable for the investigation of the inhibition of CYP3A4 not only by chemical inhibitors but also by natural food products.

Ethyl acetate extraction procedure and isocratic high-performance liquid chromatographic assay for testosterone metabolites in cell microsomes.

An isocratic reversed-phase high-performance liquid chromatography (HPLC) method was developed and validated for separation of testosterone and its main metabolites over the nominal range 20 to 40 microg/ml and 280 to 4600 ng/ml, respectively. Mobile phase composition (phosphate buffer-methanol-acetonitrile, 50:38.5:11.5) was optimised by studying the influence of numerous chromatographic parameters. The most critical one was the ratio CH3CN/CH3OH. Good recoveries (around 90% for all compounds) and an improved specificity were assessed by a double ethyl acetate extraction of biological samples. According to the performance criteria tested, the method could be applied to enzymatic inhibition and induction in vitro studies.

Cytotoxicity of polyamines to Amoeba proteus: role of polyamine oxidase.

It has been shown that oxidation of polyamines by polyamine oxidases can produce toxic compounds (H2O2, aldehydes, ammonia) and that the polyamine oxidase-polyamine system is implicated, in vitro, in the death of several parasites. Using Amoeba proteus as an in vitro model, we studied the cytotoxicity to these cells of spermine, spermidine, their acetyl derivatives, and their hypothetical precursors. Spermine and N1-acetylspermine were more toxic than emetine, an amoebicidal reference drug. Spermine presented a short-term toxicity, but a 48-h contact time was necessary for the high toxicity of spermidine. The uptake by Amoeba cells of the different polyamines tested was demonstrated. On the other hand, a high polyamine oxidase activity was identified in Amoeba proteus crude extract. Spermine (theoretical 100%) and N1-acetylspermine (64%) were the best substrates at pH 9.5, while spermidine, its acetyl derivatives, and putrescine were very poorly oxidized by this enzyme (3-20%). Spermine oxidase activity was inhibited by phenylhydrazine (nil) and isoniazid (approximately 50%). Mepacrine did not inhibit the enzyme activity at pH 8. Neither monoamine nor diamine oxidase activity (approximately 10%) was found. It must be emphasized that spermine, the best enzyme substrate, is the most toxic polyamine. This finding suggests that knowledge of polyamine oxidase specificity can be used to modulate the cytotoxicity of polyamine derivatives. Amoeba proteus was revealed as a simple model for investigation of the connection between cytotoxicity and enzyme activity.

Chlordiazepoxide photoisomerization kinetics into oxaziridine. A HPLC study.

It was proved that the N(4)-oxide group included in chlordiazepoxide (CDZ) is involved in its phototoxicity. At a wavelength of 350 nm, CDZ photoisomerizes only into oxaziridine (OXA) which is not available as standard. In the course of cytotoxicity investigations, the optimal CDZ irradiation conditions were established as acetonitrile as solvent, 10 degrees C as temperature of the irradiated solutions and 70-90 min as irradiation time for solutions in the range of 12.2-152.0 microg/ml. The kinetic parameters of the CDZ photodegradation reaction order have been calculated using an appropriate algorithm. In all cases, the first order reversible or irreversible was selected by Akaïke's criteria. The percentage of undecomposed CDZ and OXA generated after irradiation were determined by a reversed HPLC method. The latter also permitted the separation of CDZ major impurities in aqueous solutions (demoxepam and 2-amino-5-chlorobenzophenone) as well as the oxaziridine of demoxepam. In this study, the experimental irradiation conditions allowed us to produce 98% pure OXA from CDZ. This HPLC method could be easily extended to the analysis of the molecules in pharmaceutical studies.

[Infertility associated with polyps of the interstitial portion of the fallopian tubes. Experience with 26 cases treated by microsurgery]. / Infertilité associée à des polypops des portions interstitielles des trompes. Expérience de 26 cas opérés en microchirurgie.

Twenty-six patients with infertility, from two to ten years, associated to 21 bilateral and 5 unilateral (with contralateral salpingectomy) cornual polyps, underwent a microsurgical procedure, either by resection and anastomosis in 19 cases, or a simple polypectomy in 5 cases and a mixed procedure in 2 cases. The rate of patency, at least for one tube, was 88.5%. The rate of intra-uterine pregnancies was 46.4% (10/26 cases, 38.5%, achieved a full term pregnancy). It is concluded that the surgical procedure, either resection of the intra-mural segment of the tube, or a simple polypectomy, must be considered in case of large polyps, after at least three years of infertility.

[Microsurgical tubal anastomosis. A new suture technic]. / Anastomoses tubaires microchirurgicales. Nouvelle technique de suture.

A modification of the conventional tubal anastomosis technique bearing on the suture of the musculo-muscular layer is described. The extra-mucosal suture suggested is the most important point of the operation. The new technique applies to isthmo-isthmic, isthmo-interstitial and isthmo-uterine anastomoses but also to ampullo-isthmic, interstitial or uterine anastomoses. Two separate continuous sutures with a non-absorbent 8/0 or 9/0 thread are performed, one at 4, 6 and 8 hours, the other at 10, 12 and 2 hours, then ligated together. The advantages of this technique is that it is more rapid and less traumatic than others and gives very good anatomical and functional results.

Brugia-like filarial infection acquired in the United States.

A mature male filarial worm was found in sections of an enlarged, painful retroauricular lymph node removed from an 18-year-old resident of New Jersey. On the basis of its morphology and location in an obstructed lymph vessel, the worm was identified as probably a species of Brugia, possibly Brugia beaveri, a parasite of the raccoom. The infection in this case resembled one reported earlier from the same general area of the country, New York City. In the absence of demonstrable microfilaremia in this and other cases of zoonotic filariasis acquired in the United States, specific drug treatment after surgical removal of the worm is usually unnecessary.