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Biomedical subjects

S Mousset

Publications and source records attributed to S Mousset.

At least 37 records · Page 2Linked to original sources

[Value of correlated immunofluorescence and immunoperoxidase study of monoclonal markers in 2 adult cases of histiocytosis X].

Two cases of adult histiocytosis X have been studied using monoclonal antibodies on skin sections by two techniques: indirect immunofluorescence and immunoperoxidase. This study confirm: --that histiocytosis X express two specific antigens Ia and T6, --the relations between Langerhans cell and histiocytosis X. Especially, it suggests that histiocytosis X cell would be a dedifferentiated cell with receptors OKT4 and OKT10.

Adult↗

[Rothmund-Thompson syndrome with glaucoma. Endocrine study].

Two cases of Rothmund-Thomson syndrome in siblings are described. The elder patient, whose case was best documented and who was followed for several years, had the characteristic skin changes of poikiloderma congenitale with small stature and mental deficiency. Upon ophthalmologic examination, this patient was shown to have bilateral glaucoma which was treated surgically, while the cataract typically found in Rothmund-Thomson syndrome was lacking. Primary hypogonadism was confirmed by endocrinologic investigations; anterior pituitary hormones were normally released. With reference to this observation differential diagnosis is discussed; the medical literature is reviewed.

Abnormalities, Multiple↗

[Histiocytosis X with partial antehypophyseal deficiencies. 2 cases].

Diabetes insipidus is the most common endocrine disturbance associated with chronic multifocal form of histiocytosis X. Involvement of the hypothalamus can lead to growth hormone deficiency and short stature in children. Two cases with hypogonadism, growth hormone deficiency and diabetes insipidus are reported. In a 22-year-old man plasma testosterone was low and increased after administration of human chorionic gonadotrophin. Cutaneous and lytic bone lesions disappeared after treatment with Vinblastin. Partial diabetes insipidus was treated with clofibrate. A 59-year-old woman was found to have low pituitary gonadotrophins that failed to rise after administration of gonadotropin-releasing hormone and hyperprolactinemia. Fatal outcome was associated with polyuria, bone, cutaneous, gut and hypothalamic infiltration by histiocytes. There was no direct involvement of the anterior pituitary gland.

Adult↗

[Wells' syndrome or eosinophilic cellulitis. Apropos of 2 cases. Review of the literature].

In 1971, four cases of a new dermatosis were described by Wells, under the name of recurrent granulomatous dermatitis with eosinophilia. In 1978, eight additional cases were reported by Wells and Smith and three authors suggested a shorter title: eosinophilic cellulitis for this syndrome. Since then, four additional cases were published in the literature. We report here two additional cases. From these eighteen upto now published cases, there is no doubt that this dermatosis, as initially described by Wells, is a distinct entity. Clinical course is characterized by sudden eruption of large infiltrated, itchy and/or painful plaques. Blisters are often associated. During the two or three weeks following the initial rash, the inflammatory aspect disappears. Lesions become indurated, and may resemble morphea. Spontaneous resolution occurs after about six weeks. Recurrences are constantly observed. Histologic features are a striking eosinophilic infiltrate associated with eosinophilic deposits constituting flame figures. Blood eosinophilia is present in most cases. Etiology of this entity remains unknown.

Adult↗

Induction of DNA single-strand breaks by T2 toxin, a trichothecene metabolite of fusarium: effect on lymphoid organs and liver.

T2 toxin, a trichothecene metabolite produced by Fusarium species, contaminates cereals harvested and stored under damp and cold conditions. These substances are responsible for Alimentary Toxic Aleukia (ATA), a severe human disease, and numerous animal intoxications. The action of T2 toxin on DNA was studied by using Parodi's alkaline elution technique coupled with a microfluorimetric determination of DNA. In vivo the effect of the toxin was studied on liver, spleen and thymus, and in vitro on a primary culture of rat hepatocytes and on splenic and thymic lymphocytes stimulated by PHA. Under our experimental conditions, in vivo and in vitro, no damage was observed for the hepatic DNA. By contrast, the DNA of lymphoid organs was severely damaged by the toxin. In vitro, T2 toxin induced severe damage to the DNA molecule with low concentrations (5 ng/ml culture) and for short exposure (2 h). In vivo, a moderate amount of DNA breaks was observed in splenic and thymic lymphocytes 3 h after administration of T2 toxin to mice (3 mg/kg). Reversibility occurred 24 h later under these conditions in vivo, indicating DNA repair. The results agree with the preferential cytotoxicity of T2 toxin for lymphoid cells. The relation between DNA damage, mutagenicity and carcinogenic properties of T2 toxin is discussed.

Animals↗

Presence of benzo[a]pyrene metabolizing activities in isolated rat liver nucleoli.

A benzo[a]pyrene (B[a]P) hydroxylase activity and epoxide hydrolase (EH) activity have been found in rat liver nucleoli obtained from untreated (C) and 3-methylcholanthrene (3-MC) pretreated rats. A comparison of the enzyme activities was made in rat nuclei and nucleoli. Light and electron microscopic observations of nucleolar preparations did not reveal significant contamination either by intact nuclei or by nuclear membranes, and glucose 6-phosphatase, a marker of microsomal activity, was not detected in our nucleolar preparations. NADPH cytochrome c-reductase could be measured in C and 3-MC nuclei and very low but detectable activity was found in the nucleoli. Nucleolar preparations revealed significant hydroxylating activity, which was inducible by 3-MC in nuclei but not in nucleoli. The presence of EH in nucleoli was demonstrated with phenanthrene 9,10-oxide and B[a]P 4,5-oxide, but the nucleolar activities were lower than those obtained using intact nuclei. The addition of 1,1,1-trichloropropene 2,3-oxide completely inhibited EH activity. Furthermore the presence of covalently-bound metabolites of B[a]P formed in isolated nucleoli was demonstrated by cytofluoromicroscopy.

Animals↗

Immunosuppressive properties of a factor isolated from adult rat liver.

We have isolated from normal and regenerating rat liver a protein fraction 80,000 molecular weight which inhibits the multiplication of LF hepatoma cells in culture and decreased the 3H-thymidine incorporation into liver DNA in two thirds hepatectomized rats. In the present work, we have shown that this factor possess some immunosuppressive properties. It inhibits the blastogenic response to mitogens for both splenic and thymic cells, in vitro as well as in vivo; the synthesis of SRBC-antibodies is also impaired. Thus this factor which acts upon liver homeostasis seems to play a role as modulator of the immune response.

Animals↗

[Contamination of cow's milk during ingestion of small quantities of aflatoxin].

Sixteen cows, some in the early and the rest in the late lactation period, were given daily, during a eight day period a ration of peanut meal naturally contaminated by aflatoxin. The analysis for aflatoxin M1 of the milk obtained from these cows indicates the following points: --the level of aflatoxin M1 is not influenced by the volume of the daily milk secretion; --the quantity of this hydroxy-derivative expressed as a percentage of the parent toxin varies from 0.14 to 0.34 in the animals in the late lactation period, and from 0.66 to 0.95 in the cows producing some twenty litres of milk per day; --in order to achieve a tolerance limit of 20 ng/kg of aflatoxin M1, in the milk, the daily ingestion of the mycotoxin by cows should not exceed 90--100 micrograms per animal.

Aflatoxin B1↗

Effect of an inhibiting factor isolated from rat liver on DNA polymerases in regenerating rat liver.

We partially purified an inhibitory factor (LIFE), isolated from 105,000 g supernatant of a saline adult rat liver homogenate. LIF stopped in vitro cell multiplication by blocking the G1--S transition, and reduced in vivo [3H]thymidine incorporation into liver DNA in two-thirds hepatectomized rats. This reduction in DNA synthesis was observed at 24 hr after hepatectomy, even when the LIF was injected before the beginning of the S phase, 10 hr after hepatectomy, i.e. when DNA polymerase activity had not yet increased. Under these experimental conditions, LIF in vivo treatment prevented alpha DNA polymerase activity from increasing after partial hepatectomy, so that enzyme activity at 24 hr in LIF-treated rats decreased compared to the controls. No direct inhibitory effect of LIF on alpha DNA polymerase was detected. LIF did not affect beta DNA polymerase. These results suggest that LIF plays a part in controlling liver growth.

Animals↗

Characterization of a soluble simian-virus-40 transcription complex.

We have previously described the isolation, from nuclei of monkey cells infected with Simian virus 40 (SV40), of a nucleoprotein complex which is able to achieve viral transcription. This complex contains SV40 DNA and RNA polymerase II molecules which have initiated transcription during the viral development. We show here, by molecular hybridization experiments, that most of the templates active in SV40 transcription can be dissociated from host DNA. In conditions where supercoiled SV40 DNA form I sediments at 21 S, the transcription complex has a sedimentation coefficient of about 25 S. Inhibition of viral DNA synthesis by cytosine arabinonucleoside or chloroquine does not affect the activity of the transcription complex, which suggests that replicating molecules are not required for viral RNA synthesis and that SV40 DNA form I could serve as template for late SV40 transcription. A large fraction of the RNA synthesized in vitro remains associated with the SV40 DNA template in cesium sulfate density gradient. The RNA chains produced by the complex are heterogeneous in size, most of them being as large or larger than the viral genome.

Cell Line↗