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Biomedical subjects

F Simon

Publications and source records attributed to F Simon.

At least 127 records · Page 7Linked to original sources
PubMed1994

[Bone and joint sites of African histoplasmosis (Histoplasma duboisii). Apropos of a case and review of the literature].

The authors report a case of disseminated African histoplasmosis with bone and joint involvement in a black 28-year-old citizen of the Central African Republic who presented with a 17-month history of multiple osteoarticular lesions (sternoclavicular joints, humerus, ribs), cutaneous lesions (face, scalp, thorax), and lymphadenopathy. Clinical manifestations resolved rapidly under treatment with ketoconazole (600 mg/d for 10 days then 400 mg/day for nine months). Persistent yeast cells were then found upon examination of a lymph node biopsy specimen. The characteristics and diagnosis of osteoarticular lesions due to African histoplasmosis are discussed on the basis of a review of the literature. Bone and joint lesions due to African histoplasmosis have not yet been reported in patients with the acquired immunodeficiency syndrome. However, the expanding epidemic of human immunodeficiency virus infection in Africa can be expected to result in an increase in the incidence of African histoplasmosis. Imidazole derivatives are easier to use on a long-term basis than amphotericin B and have significantly improved our ability to treat African histoplasmosis.

AIDS-Related Opportunistic Infections↗
PubMed1994

[Aorto-esophageal fistula. Apropos of a case].

One case of aortoesophageal fistula is presented. This pathology is rare: most of aortoenteric fistulas are in the duodenojujunum. Clinical presentation is rarely as clear as the Chiari triad describes it: mild thoracic pain, sentinel arterial hemorrhage and exsanguination. Esophagoscopy, computed tomography and arteriography are helpful for diagnosis. Issue is fatal without surgery but patients are often too old to tolerate it.

Aged↗
PubMed1994

[A case of nasal entomophtoral phycomycosis observed in an arid African region (Somalia)].

On the African continent, rhinophycomycosis entomophtorae, a deep mycosis due to Conidiobolus coranatus, has been encountered mainly in wet forest areas. Only one case, which involved a Tchadian, has been reported in a dry zone. The present report describes a case observed in a 30-year-old Somalian, who lived all his life in the rural zone of Dinsoor where the climate is hot (temperature between 22 degrees C and 30 degrees C) and dry (annual rainfall less than 400 mm). In this patient, diagnosis was based on the presence of a characteristic bifocal deformation of the central region of the face and on histological findings typical of rhinophycomycosis entomophtorae. This case underlines the fact that this deep mycosis can occur outside of wet forest areas in Africa. Thus practitioners should not rule this diagnosis out simply on the basis of climatic conditions.

Adult↗
PubMed1993

Mammalian PC-12 cell genetically engineered for human cytochrome P450 2E1 expression.

The stable expression of the human cytochrome CYP2E1 (P450 alcohol) was performed in the mammalian cell line PC-12. This cell line expressed cytochrome b5 (58 +/- 12 pmol/mg microsomal protein vs 528 +/- 80 pmol/mg in microsomal human liver) and a high level of NADPH: cytochrome P450 reductase (140 +/- 20 nmol.min-1.mg microsomal protein-1 vs 68 +/- 48 nmol.min-1.mg-1 in microsomal human liver). An expression plasmid was constructed using the cDNA for the human CYP2E1 mRNA and the Rous sarcoma virus (RSV) promoter. This plasmid was co-transfected with the plasmid RSVneo into PC-12 cells. Clones were selected for resistance to the neomycin analog, G418, and then screened for expression of the CYP2E1 isozyme by testing for 6-hydroxylation of chlorzoxazone, a specific substrate for CYP2E1. Expression of CYP2E1 was confirmed in one clone, DB-7, by Western blot analysis and by measurement of monooxygenase activities which were not detectable in PC-12 cells. Chlorzoxazone 6-hydroxylation, n-butanol oxidation and dimethylnitrosamine N-demethylation were localized in microsomes (62, 60 and 63 pmol.min-1.mg microsomal protein-1, respectively) and were inhibited by carbon monoxide and diethyldithiocarbamate, both inhibitors of P450 enzymes. Although the level of the enzyme activities was about a tenth of that measured in human liver microsomes, CYP2E1 expressed in DB-7 cells has catalytic competence similar to human liver CYP2E1. DB-7 cells metabolized acetaminophen and this metabolic activation was shown to be toxic to these cells by release of lactate dehydrogenase. Construction of recombinant cell lines expressing CYP2E1 provides a useful tool for studying the catalytic properties of this enzyme and the consequent cytotoxic effects of substrates metabolized by this enzyme.

1-Butanol↗
PubMed1993

Cellular and plasma viral load in patients infected with HIV-2.

OBJECTIVE: To determine circulating viral load in HIV-2-infected individuals. METHODS: Viral load was determined in 40 HIV-2-infected adults using standardized quantitative cell and qualitative plasma viraemia assays. We also tested for proviral HIV-2 DNA using single and nested polymerase chain reaction (PCR) in fresh lymphocytes from 27 subjects. The results were compared, on the basis of the CD4+ lymphocyte count, with our published data for HIV-1 infection. RESULTS: HIV-2 was isolated from peripheral blood mononuclear cells (PBMC) from 19 individuals and plasma from four patients. The rate of cell and plasma viraemia positivity correlated with the CD4+ cell count and HIV-2 virus load increased as the CD4+ cell count fell. The cellular HIV-2 load in the patients with a CD4+ count < 200 x 10(6)/l was similar to reported values for HIV-1, but the HIV-2 isolation rate from the plasma of these individuals was significantly lower than for HIV-1. When the CD4+ count was between 200 and 500 x 10(6)/l, the rate of HIV-2 isolation from plasma and the cellular virus load were both significantly lower than for HIV-1. When the CD4+ count was > 500 x 10(6)/l, HIV-1 and HIV-2 were undetectable in plasma and HIV-1 was isolated from PBMC in significantly more cases than HIV-2. By single PCR, amplification were positive in 14 out of 27 subjects and there was a correlation between positivity and CD4+ cell count. By nested PCR, only four of the 27 subjects, all with a high CD4+ count, remained negative. CONCLUSIONS: Differences in viral load between individuals infected with HIV-2 and those infected with HIV-1 could partly account for reported differences in the pathogenicity of the two viruses.

Adult↗
PubMed1993

[Concordant and nonconcordant attributes in Latin anatomic nomenclature].

Comparison of the original edition of anatomical nomenclature published in 1955 with its revised version dating from 1965, 1975 and 1985 confirmed the distinct trend of preferring the concordant attribute over the nonconcordant one in the later editions, i.e. adjectives rather than the genitive. Some changes, however, defy explanation and neither can the further development be predicted. The author considers it as unfavorable that the unwritten rule on using the adjective or the genitive in expressing localization in anatomical nomenclature is being abolished. (Ref. 9).

Anatomy↗
PubMed1993

Evolution of chloroquine resistance in central and west Africa.

The evolution of in vitro chloroquine susceptibility of clinical isolates of Plasmodium falciparum obtained from travellers returning to France was studied between 1986 and 1991 using the isotopic semi-microtest. Based on the analysis of 1,147 interpretable tests on isolates originating from Central and West Africa, the study showed that the proportion of chloroquine-resistant falciparum malaria remained stable between 1986 and 1988 and has diminished between 1989 and 1991. The diminution of chloroquine-resistant imported malaria may be associated, at least in part, with a better compliance of French travellers with the recommendation to use either mefloquine or a combination of chloroquine and proguanil since 1989 and an increasing proportion of African immigrants who tend to neglect regular chemoprophylaxis during the visit to their countries. The reason for the stabilisation of chloroquine resistance is unknown, and this phenomenon may be temporary, necessitating a continuous surveillance of drug susceptibility.

Africa, Central↗
PubMed1993

Antibody avidity measurement and immune complex dissociation for serological diagnosis of vertically acquired HIV-1 infection.

Differences in avidity between HIV-1 antibodies transmitted passively and antibodies synthesized by children born to HIV-1-positive mothers can be measured using a commercially available competitive enzyme immunoassay kit. The avidity determination method is based on the competition between an anti-HIV-1-peroxidase-labeled antibody at a stable and known concentration and the anti-HIV-1 antibodies (IgA, IgG, IgM) present in the child's serum at various and increasing dilutions. The shift in the competition/dilution curves between serum samples taken at the third and the sixth month of the child's life showed either the loss or the synthesis of anti-HIV-1 antibodies. The antibody avidity determination combined with a test detecting free or complexed p24 antigen is a workable and inexpensive serological method for the follow-up of children born to seropositive mothers. Combining these two complementary methods, HIV-1 infection has been established at 6 months of age in 13 of 13 infants, and positive results were confirmed by coculture and by PCR. An HIV-1 infection was excluded at 6 months of age in 17 of 17 infants, results otherwise confirmed by virological and clinical follow-up. These new and convenient approaches to the diagnosis of vertically acquired HIV-1 could be used worldwide, including in developing countries.

AIDS Serodiagnosis↗
PubMed1992

The phase of PVEP in Maxwellian view: influence of contrast, spatial and temporal frequency.

The temporal phase of the pattern reversal VEP has been investigated using stimulation with laser interference fringes in Maxwellian view. VEP phase was almost constant as function of spatial frequency (2-30 c/deg, 6.5 r/sec, 51 subjects). The phase function however shows a small phase increase at low spatial frequencies consistent with the existence of multiple temporal mechanisms. Contrast variation yields a smaller phase increase with decreasing contrast than conventional stimulation. The phase is linear as function of reversal rate (2-31 r/sec) for low and high spatial frequencies. The indication of more than one temporal mechanism has also been found when the test field diameter was varied. With decreasing test field size the phase increases at 6.5 r/sec, but decreases at 18 r/sec (for 12 c/deg).

Adult↗