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Biomedical subjects

F Deschamps

Publications and source records attributed to F Deschamps.

At least 19 recordsLinked to original sources
PubMed2001

Micellar electrokinetic capillary chromatography quantification of cytosine arabinoside and its metabolite, uracil arabinoside, in human serum.

Cytosine arabinoside (Ara-C) is widely used to induce remission in adult granulocytic leukemia. High doses can be infused in refractory leukemia or in relapse. After injection, Ara-C is quickly metabolized to uracil arabinoside (Ara-U), the main inactive metabolite. We here described a micellar electrokinetic capillary chromatography (MECC) method to simultaneously determine Ara-C/Ara-U in human serum using 6-O-methylguanine as an internal standard. The assay was linear from 6.25 to 200 microg/ml with a quantification limit between 3 and 6 microg/ml. The analytical precision was satisfactory between 2 and 4.3% (within-run) and 3.7 and 7.3% (between-runs). This assay was applied to the analysis of serum from acute granulocytic leukemia patient treated by high doses cytarabine (3 g/m2 body surface).

Antimetabolites, Antineoplastic↗
PubMed2000

Magnetic field desensitizes 5-HT(1B) receptor in brain: pharmacological and functional studies.

It was previously suggested that exposure to magnetic fields (MFs) could generate dysfunction of the CNS. The physiological manifestations described lead us to postulate that these symptoms might be related to a dysfunction of the serotonergic system and particularly of the 5-HT(1B) receptors. Accordingly, MFs could modify the conformation of these receptors altering their functional activities. In rat brain membrane preparations, we showed that the affinity constant of 5-HT for 5-HT(1B) receptors was modified under exposure to MFs since K(d) varied from 4.7+/-0.5 to 12+/-3 nM in control and exposed (2.5 mT) membranes, respectively. This effect was intensity-dependent (the sigmoidal dose-response curve was characterized by an EI(50) of 662+/-69 microT and a maximal increase of 321+/-13% of the control K(d)), reversible, temperature-dependent and specific to the 5-HT(1B) receptors. Similar results have also been obtained with the human 5-HT(1B) receptors. In parallel assays, the functional activity of 5-HT(1B) receptors was investigated. The capacity of a 5-HT(1B) agonist to inhibit the cAMP production was reduced by 37% (53.7+/-3.5% to 33.7+/-4.1%) following exposure to MFs and the cellular activity of the receptors (inhibition of the synaptosomal release of 5-HT) also was markedly reduced (66.5+/-3.2% to 28.5+/-4.2%). These results clearly show that in in vitro assays, MF specifically interacts with 5-HT(1B) receptors, inducing structural changes of the protein that result in a functional desensitization of the receptors. Thus, in vivo, exposure to MFs may lead to physiological changes, particularly in the field of mood disorders where the 5-HT system is strongly involved.

Animals↗
PubMed1999

Comparison of benzo[a]pyrene DNA adduct formation in the skin of two strains of mice selected for resistance (DBA/2) or susceptibility (C3H/HeN) to contact dermatitis.

Two strains of mice were selected for resistance (DBA/2) or susceptibility (C3H/HeN) to contact dermatitis. Benzo[a]pyrene-DNA adduct formations was compared in the two mouse strains by a postlabeling procedure to determine if there was a significant effect. Results showed that adduct profiles in DBA/2 and C3H/HeN dermis were qualitatively similar. The total binding levels were higher in DBA/2 mice on the d 2 and the d 10. DNA adduct formation has been shown to inversely correlate with skin allergy induction. Data suggest that the expression of the genes responsible for the differences in responsiveness to chemical induced contact dermatitis in mouse may play an important role in benzo[a]pyrene-DNA adduct formation.

Animals↗
PubMed1999

Specific expression of the Fusarium transposon Fot1 and effects on target gene transcription.

The Fot1 transposon is active in some strains of the plant pathogenic fungus Fusarium oxysporum. In a high-copy-number strain that contains autonomous elements, we have detected a transcript of 1.7 kb hybridizing to Fot1 in very low amounts. Mapping the 3' and 5' termini of this transcript confirms that it corresponds to a Fot1-specific transcript. In this strain, five independent mutants of the transgene (niaD) encoding nitrate reductase have arisen by insertion of Fot1 into the third intron. The analysis of the effect of Fot1 insertion in these mutants shows that, depending on the orientation of Fot1 relative to niaD, different truncated chimeric niaD-Fot1 transcripts are produced. Mapping the 5' and 3' ends of these transcripts reveals (i) premature polyadenylation at sites present in the 5' and 3' untranslated regions of Fot1, and (ii) initiation of some transcripts in the 3' part of the niaD gene at sites located immediately downstream of the Fot1 insertion. Thus, a novel promoter, associated with the end of Fot1, directs transcriptional activity outwards from the element into the coding sequence of the niaD gene. These effects demonstrate that Fot1 insertion provides an additional general mechanism controlling fungal gene expression.

Alleles↗
PubMed1999

Relationships between work and HIV/AIDS status.

The aim of this study was to assess reasons contributing to a cessation of occupational activities in HIV-infected persons. One hundred patients were studied, 55 of whom were working at the time of the study while 45 were unemployed. Twenty of the patients had been diagnosed as having AIDS and the remaining patients were HIV-positive. The main causes of work cessation were psychological, not physical, symptoms. Disclosure of HIV status to work colleagues or employers does not seem to have an effect on employment.

Adult↗
PubMed1999

Ultrasound-assisted laparoscopic creation of a neovagina by modification of Vecchietti's operation.

BACKGROUND: In performing Vecchietti's operation laparoscopically, it is important to ensure bladder and rectum integrity. We report new techniques of ultrasonography and suture retrieval that simplify and improve the ease and speed of this operation. TECHNIQUE: The pneumoperitoneum is emptied and the bladder filled with 200 mL of sterile water. The ultrasound probe is placed on the suprapubic wall for a sagittal image. The needle progresses medially through the vesicorectal space, with ultrasound guidance, and its emergence into the pelvis is controlled with laparoscopy. The nylon sutures carrying the dilation ball are threaded through the needle and brought back through the abdominal wall. EXPERIENCE: Seven patients with vaginal aplasia had this procedure. There were no complications, and the mean operative time was 43 minutes (range 35-55). Mean vaginal length was 7 cm (range 6-10). Four women defined sexual intercourse as very satisfying and two as moderately satisfying. CONCLUSION: This original technique was used for easy, safe, and rapid creation of neovaginas.

Adolescent↗
PubMed1999

[Prenatal diagnosis of bilateral polycystic kidney disease in a twin pregnancy].

Polycystic renal dysplasia is a lethal malformation when it is bilateral. The authors report a rare case of polycystic dysplasia observed in both foetuses of a twin pregnancy, one of whom survived despite bilateral polycystic kidney disease. These biamniotic monoplacental twins were delivered prematurely at 33 weeks of amenorrhoea. The diagnosis was made by antenatal ultrasound. The first twin presented bilateral renal lesions: right polycystic kidney, segmental polycystic dysplasia of the superior pole of the left kidney on a completely duplicated system. The second twin presented a right polycystic kidney. In the light of this case report, the authors describe the various antenatal presentations of polycystic kidney and the associated urological malformations. Involvement of both foetuses of a twin pregnancy raises a discussion of the aetiopathogenesis of polycystic renal dysplasia.

Adult↗
PubMed1998

Prevalence of respiratory symptoms and increased specific IgE levels in West-African workers exposed to isocyanates.

Respiratory symptoms and immunological effects from chronic exposure to isocyanates (toluene diisocyanate) were studied in a cross survey of workers from West African factories producing paints and polyurethane foam. A questionnaire, a pulmonary function test, immunoglobulin E (IgE) levels, radioallergosorbent test (RAST) and an atmospheric sample to quantify isocyanate exposures were carried out in the workplace for each worker. Ninety-six workers, of whom 44 had occupational isocyanate-induced asthma, were included in the study. Twenty-four viral-infected subjects were excluded from the immunological study. Specific antibodies to isocyanates were detected in two of the symptomatic individuals. This low proportion appeared to be a common feature of this disease. The prevalence of isocyanate-induced asthma in a West African working population appears to be significant in the context of chronic human exposure, as current data are based on excessive acute exposure due to an accident as seen in India.

Adult↗
PubMed1998

Mechanisms of occupational asthma induced by isocyanates.

Isocyanates are some of the most important low molecular weight chemicals associated with occupational asthma. These compounds are often volatile and they are highly reactive on mucous membranes, especially the conjunctivae and respiratory tract. Despite numerous data derived from experimental and clinical investigations, there is no agreement concerning the real mechanisms involved in isocyanate-induced occupational asthma. In fact, the cause of occupational asthma is multifactorial. The aim of this paper is to review the involved physiological causes of isocyanate-induced asthma; the main mechanisms are immunological, pharmacological and/or irritative.

Asthma↗
PubMed1998

[Fetal intraventricular hemorrhage caused by cerebral contusion, and with spontaneous remission. Contribution of MRI].

We report a case of fetal ventricular hemorrhage which occurred at 27.5 weeks gestation and caused by fetal brain contusion after a maternal traumatism. Ultrasound examination evidenced ventriculomegaly and an intraventricular clot which were confirmed by MRI. We discuss the interest of combining ultrasound and MRI of the fetal brain for the investigation and follow-up of fetal brain trauma. The patient gave birth to an eutrophic normal boy. The child is normal at 12 months follow-up.

Accidents, Traffic↗
PubMed1998

[Early prenatal ultrasonographic diagnosis of fetus in fetu].

Fetus in fetu is a very rare abnormality, and is secondary to a pathological diamniotic monochorionic pregnancy. Its discovery is usually postnatal. We report a case of prenatal diagnosis suspected at 16 gestation's week because of a voluminous omphalocele seen at 12 gestation's week.

Adult↗
PubMed1998

[Creation of a neovagina using ultrasonography-assisted laparoscopy (modified Vecchietti technique].

Ultrasonography-assisted laparoscopic creation of a neavagina was performed on 6 patients suffering from vaginal aplasia. As the needle progress through the vesicorectal space, ultrasonography provided an accurate check of the bladder and rectal integrity, and improved the ease of the surgical procedure. Ultrasound can be considered an effective and reliable advance for laparoscopic management of vaginal aplasia.

Adolescent↗
PubMed1997

[Congenital adenomatoid cystic malformation of the lung and renal polycystosis. A fetal case report and review of the literature].

We observed a plurifocal cystic adenomatoid malformation of the lung, Stocker class II, in a 21-week gestation fetus in association with polycystosis of a solitary medial kidney. There was no other notable abnormally. The caryotype could not be obtained. The association of these two congenital malformations is exceptional, only three similar cases have been reported in the literature. Two other cases of pulmonary adenomatoid malformations associated with nephromegaly with renal hyperlobulation have also been described. Whether this is a fortuitous association or not remains to be determined.

Abnormalities, Multiple↗
PubMed1996

Prenatal aspects of giant fetal cranial haemangio-endothelioma.

A case of a large vascular lesion of the skull is reported. The lesion was discovered at 22 weeks' gestation and it rapidly increased in size, reaching 8 cm a month later. Tumor echogenicity was the same as that for soft tissues and colour Doppler examination revealed intense vascularization. Cordocentesis showed features of the Kasabach-Merritt syndrome and very high plasma levels of alpha-fetoprotein. A Caesarean section was performed to avoid dystocia and led to the birth of a baby with cardiac failure in the immediate neonatal period. Biopsies of the mass led to the diagnosis of a non-malignant haemangio-endothelioma. The mass was removed and plastic surgery performed. The baby is alive and well 9 months after the operation.

Adult↗
PubMed1996

Evaluation of urinary D-glucaric acid excretion in workers exposed to butyl glycol.

The biological follow-up of subjects exposed to butyl glycol (BG) is generally accomplished using a standard blood count that is not sensitive enough to reveal early intoxication by this molecule. For this reason we have used an indirect test for evaluating the induction of hepatic enzymes, the measurement in urine of D-glucaric acid (DGA), which reflects the activity of the glucuronic acid enzyme pathway. This study was performed on 17 foundry workers exposed to BG emissions coming from paints used in cataphoresis. The airborne concentration of BG was less than 0.3 times the average limit exposure value. This study shows that BG emissions at low concentrations are able to increase the activity of the enzymes of the glucuronic acid pathway. DGA urinary excretion increased by 165% in winter (p < .01) and by 85% (p < .05) in summer when the doors are open and the BG concentration lower. DGA urinary excretion is significantly higher in smoking than in nonsmoking exposed workers. None of these workers had a perturbed blood count. This study shows that the urinary level of DGA provides a good test for the follow-up of exposure to BG in the electrophoresis painting plant, and that the exposed smoking workers seem to be more sensitive to BG exposure than do the nonsmokers. In conclusion, the measurement of urinary DGA might be considered as a useful test for the surveillance of subjects exposed to vapors containing BG.

Adult↗
PubMed1996

Erythema multiforme due to pyrazinamide.

Drug-induced erythema multiforme is reported with many antimicrobial and antipyretic medications. We present one patient who experienced erythema multiforme and urticaria after administration of pyrazinamide for treatment of cutaneous tuberculosis. The side-effects of pyrazinamide include hepatic or dermatologic disorders, but erythema multiforme has not yet, to our knowledge, been described. Clinical features and discontinuation and reintroduction of the drug led us to consider pyrazinamide the cause of the erythema multiforme, but allergologic studies remained negative, except for the presence of circulating immune complexes. The mechanism of this eruption remains obscure, and definite withdrawal of pyrazinamide seems to be the best therapeutic choice.

Aged↗
PubMed1996

[Choledochal cyst. Prenatal diagnosis and early neonatal management].

Cysts of the main bile duct occur rarely. Antenatal diagnosis has improve med management. We demonstrate the difficulties in identifying intra-abdominal liquid collections at antenatal examinations and discuss the differential diagnosis. Certain diagnosis is established when a communication between the bile duct and the cyst can be visualized. After sonography confirmation post-natally, early surgical cure is required and has radically changed the prognosis of this condition.

Adult↗