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Biomedical subjects

R Laurent

Publications and source records attributed to R Laurent.

At least 109 records · Page 6Linked to original sources
PubMed1986

Free fatty acids and fatty acids of triacylglycerols in normal and hyperkeratotic human stratum corneum.

The content of the free fatty acids and the fatty acids of triacylglycerols has been measured in human plantar stratum corneum from normal and hyperkeratotic subjects with palmoplantar keratoderma. Fatty acids of triacylglycerols in normal tissues showed a characteristic pattern with a relative abundance of short-chain length and unsaturated fatty acids. Free fatty acid fraction was characterized by the predominance of saturated compounds. The relative amount of short-chain and monoene fatty acids in the hyperkeratotic stratum corneum was increased. These results seem to show a defect in the maturation of fatty acids in the living epidermis and present new evidence that the abnormality of lipid metabolism can influence the process of desquamation in stratum corneum.

Adult↗
PubMed1986

Genetic susceptibility to scleroderma-like syndrome in symptomatic and asymptomatic workers exposed to vinyl chloride.

We have previously reported a genetic susceptibility to a scleroderma-like disorder in a group of workers exposed to polyvinyl chloride and this susceptibility could be mapped to the major histocompatibility complex area of the 6th chromosome. To date no genetic studies have been reported comparing affected with unaffected workers. We report such data and discuss it in the light of our previous findings in vinyl chloride exposed patients and in patients with classical scleroderma. Our results suggest that susceptibility to this disorder is increased in the presence of HLA-DR5 or of a gene in linkage disequilibrium with it and an antigen associated with the haplotype A1 B8, while DR3 favours progression of the disease.

Chemical Industry↗
PubMed1985

Estrone- and dehydroepiandrosterone-sulfatase activities in human female epidermis.

Estrone (E1)-sulfatase and dehydroepiandrosterone (DHEA)-sulfatase activities were studied in human female epidermis. Skin specimens were obtained by abdominal or plantar biopsies. The apparent Michaelis-Menten constants for E1 and DHEA sulfatases were 35.2 microM and 8.7 microM, respectively. A substrate inhibition was only observed for DHEA sulfatase. Both sulfatases had an elevated temperature optimum (65 degrees C). The effect of inorganic salts was also tested. In normal epidermis, E1-sulfatase activity was constantly higher than DHEA-sulfatase activity, but no correlation between these activities was observed. On the other hand, E1- and DHEA-sulfatase activities were lower in plantar than in abdominal epidermis. In plantar epidermis of palmoplantar keratoderma, large variations in E1-sulfatase activity, but no significant variation in DHEA-sulfatase activity, were observed. In human epidermis, the findings were consistent with the existence of two different sulfatases: E1 sulfatase and DHEA sulfatase. It would also appear that sulfatase activities are not linked to the abnormal shedding of plantar stratum corneum in palmoplantar keratoderma.

Abdomen↗
PubMed1985

Composite keratohyaline granules in palmoplantar keratoderma: an ultrastructural study.

We report the results of an ultrastructural study of the hyperkeratotic epidermis in 23 cases of palmoplantar keratoderma (PPK) comprising 8 inherited keratoderma, 8 keratoderma climactericum in menopausal women and 7 symptomatic keratoderma. In all but one of the cases of inherited PPK and keratoderma climactericum, composite keratohyalin (KH) granules were found in granular cells of the interductal epidermis, which were similar to those found in the rat and in some other conditions. In the cases of symptomatic keratoderma, e.g. secondary to eczema, the appearance of the KH granules did not differ from that of granules observed in two normal plantar skin samples. While the real role played by these granules is unknown, they could constitute a differentiation marker of intraepidermal duct cells, and their abundance in PPK suggest that intraepidermal sweat ducts may play a part in PPK histogenesis.

Adult↗
PubMed1985

[Epidemiologic characteristics of 21 peranesthetic anaphylactoid accidents observed in a population of 12,855 surgically treated patients].

A study of anaphylactoid reactions (AR) observed between September 1982 and September 1983 was carried out in the surgical departments of a French regional hospital. The patients who had presented clinical symptoms suggesting an AR (bronchospasm, collapse, tachycardia, with or without skin rash) during a general anaesthesia were included in this study. A precise history of previous anaesthesias and allergy was taken; allergological testing was carried out six to eight weeks after the AR. It included intradermal skin tests (ST) and a human basophil degranulation test (HBDT) with the suspected drugs. Out of 12,855 patients operated on under general anaesthesia in the hospital, 21 AR were seen during the year under study, in 18 women and 3 men, of median age 27 years (extreme values: 11 and 62). The median number of previous anaesthesias was 2 (extreme values: 0--in 4 cases- and 22). Cardiocirculatory abnormalities were the most frequent clinical symptoms of the AR: they consisted of decreased arterial pressure in 13 cases, with 8 cases of vascular collapse. Respiratory symptoms were less frequent but severe bronchospasm was observed in 5 cases. Skin rashes were seen simultaneously in 13 out of the 21 observations. A history of allergy was found in 11 patients. Total IgE serum concentration averaged 134 kU X 1(-1) (extreme values: 32-378). Results of histamine-sensitivity skin tests were not significantly different from those observed in a control group. Calcemia and magnesemia were in the normal range. One to four drugs were tested in each patient: 41 tests combining ST and HBDT were carried out.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Role of an anti-estrogen, tamoxifen, in the treatment of metastatic malignant melanoma].

The hormone-dependence of malignant melanoma is brought to mind by some epidemiological facts (rarely found in children, more frequently in females, higher frequency in case of prolonged use of oral contraceptives from an early age). On the other hand, estrogen receptors can be found in about 30 p. 100 of malignant melanomas. Starting from this hypothesis of a sub-population of hormone-dependent malignant melanomas, it seemed of interest to us to study the efficiency of an anti-estrogen, namely Tamoxifen (Nolvadex) in the management of metastatic malignant melanoma. It was used at a 40 mg daily dose-regimen on four patients (three post-menopausal females, one male) with multiple estrogen positive cutaneous metastases. In post-menopausal women, two cases of total regression were observed, associated with a distinct increase in progesterone receptors while under treatment and with a return to the initial stage when the treatment was stopped. This phenomenon can be explained by a double self-contradictory effect of the drug, already well known in other hormone-dependent cancers such as those of the breast or the endometrium, namely an anti-estrogen result on the tumoral growth and an estrogen result as attested by the synthesis of progesterone receptors. Certain malignant melanomas therefore behave as endocrine-dependent tumours and may so answer an anti-hormone treatment through a competitive fixation on estrogen-receptors. Our clinical results are in agreement with such a theory since Tamoxifen is at best effective on cutaneous metastases of post-menopausal women. The overall efficiency on all metastases is of the order of 10.6 p 100 (complete or partial regression).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

[Fatty acids in normal and pathological stratum corneum of humans].

Fatty acids of triacylglycerols and free fatty acids have been studied in normal and hyperkeratotic human plantar stratum corneum. The results emphasize a decrease of long-chain fatty acids (greater than C18) in the hyperkeratotic tissues. Possible explanation for these findings are discussed in relation to the fatty acids metabolism in living epidermis.

Chromatography, Gas↗
PubMed1984

A comparison of indoprofen and indomethacin in the treatment of ankylosing spondylitis.

A double-blind, crossover trial was carried out to compare the effectiveness and tolerance of indoprofen with indomethacin in the treatment of ankylosing spondylitis. Nineteen patients entered the study and 1 was withdrawn for reasons unrelated to therapy. Patients received 4-weeks' treatment in random order, with 200 mg indoprofen 4-times daily and 25 mg indomethacin 4-times daily. Most subjective and objective clinical measurements of disease activity showed a comparable degree of improvement with either drug although few statistically significant changes were observed. There was no statistically significant difference between treatments and, although gastro-intestinal side-effects occurred more commonly with indoprofen, patients known to be intolerant of indomethacin had been excluded from this trial.

Adult↗
PubMed1983

[Systemic manifestations and diseases related to positive serology for Yersinia pseudotuberculosis. Apropos of 9 observations].

A series of 9 cases of systemic affections associated with positive serology for yersinia pseudotuberculosis is reported. The clinical presentation of four cases was classical reactive arthritis with or without erythema nodosa; in two cases the patients had sacroileitis or Reiter's syndrome. The other three patients had unusual presentations: one Löfgren's syndrome, one cutaneous leukocytoclasis vasculitis with polyarthritis and glomerulonephritis, and one rhizomelic pseudopolyarthritis. Four patients (45 p. 100) had a positive HLA B27 antigen. In the absence of absolute bacteriological proof of cause and effect the authors discuss the relationship between these syndromes and Yersinia pseudotuberculosis infection. Although a Yersinia infection has not been formally established as the cause, there is some indirect evidence pointing to the reality of systemic Yersinia pseudotuberculosis infection.

Adult↗
PubMed1983

Humoral and cell-mediated immunity to human papillomavirus type 1 (HPV-1) in human warts.

The humoral and cell-mediated immune response to human papillomavirus type 1 (HPV-1) has been studied in 162 patients carrying papillomas of various clinical types: deep plantar wart or myrmecia, common wart, flat wart, and anogenital wart. Circulating antibodies were detected by immunodiffusion and microcomplement fixation, using purified HPV-1 particles as type-specific antigen. A significant association between myrmecia and anti-HPV-1 antibodies was found (39% of the cases). Cell-mediated immunity was evaluated by a study of delayed hypersensitivity (DH). The main capsid components of HPV-1 (HPV-1 CP), consisting mostly of a polypeptide of molecular weight 54,000, were injected intradermally. In addition to the type-specific antigens, HPV-1 CP contain other antigenic determinants shared by various types of human papilloma-viruses and masked in intact viral particles. The DH tests to HPV-1 CP showed no differences between the carriers of different papilloma types, confirming the presence of common antigenic determinants. Moreover, they gave rise to an increase or to new anti-HPV-1 antibody production mostly in myrmecia carriers (78% and 33% of the cases, respectively), and to new DH to HPV-1 CP in all groups of papilloma carriers (33% to 56%, depending on the clinical papilloma type).

Adolescent↗
PubMed1983

Chronic arthritis associated with the presence of intrasynovial rubella virus.

In this report we present 21 instances in which live rubella virus was isolated from synovial fluid obtained from 6 cases of inflammatory oligoarthritis or polyarthritis over a period of 2 years in the absence of firm clinical evidence of rubella. In 3 cases (cases 1, 2, 6,) a persistent oligoarthritis predominantly affecting the knee joints occurred in 2 adult women and one man, lasting to date 27, 29, and 18 months respectively, and in one of these cases virions were found in cells of the synovial membrane. In case 3 a boy of 9 presented with an illness indistinguishable from the systemic variety of juvenile chronic arthritis (Still's disease). In case 4 a young man with persistent monoarthritis was found to have ankylosing spondylitis, and in case 5 a progressive erosive polyarthritis developed 5 years after an attack of rubella complicated by rubella arthritis. The virus was identified by a variety of virological techniques and infection confirmed by immunofluorescence and (in one case) electron microscopy.

Adult↗
PubMed1983

[Skin manifestations of Still's disease in adults. Apropos of 4 cases].

The authors report four new cases of Still's disease in adult. Each time, the clinical picture associated the following triad: fever, joint involvement and skin rashes. The latter consisted in non-pruritic but sensitive maculo-papular and disseminated lesions, the mean course of which lasted 24 to 48 hours and were readily accompanied by the two other components of the basic clinical triad. Laboratory investigations were non-specific but constantly included a polymorphonuclear leucocytosis and a raised ESR, the mean value of which reached 80 mm in the 1st hour. Antinuclear factors were not demonstrated, but circulating immune complexes were found on several occasions in three out of the four reported cases. Histopathological changes observed were those of a superficial and mid cutis edema, associated with a diffuse or perivascular infiltrate in which either mononuclears or polymorphonuclears were prominent. Dermal vessels involvement appeared rather weak, including swelling of the walls by edema with focal fibrinoid necrosis. Direct immunofluorescence showed mainly IgG, IgA and C3 vascular deposits. Based on these data, an immune pathology is discussed, besides the more classic infections pathogenesis.

Adult↗
PubMed1982

[Herpes gestationis: immunologic findings].

The treatment of herpes gestationis has been considerably changed in recent years by progress in electron microscopy and immunology. Herpes gestationis, a rare polymorphic vesiculo-bullous pruriginous dermatosis, occurs during pregnancy or the post-partum period. It evolves by acute periods of several weeks, and relapses during later pregnancies or on taking oestro-progestagens. Histologically, the bulla is situated at the dermo-epidermic junction. The epidermal oedema is both intra and extra-cellular. The ultrastructural studies show the importance of the oedema and the changes in the plasma membrane of the basal cells in the onset of the vesicles and the bullae. The immunological inquiry gives diagnostic certainly when one discovers under indirect immuno-fluorescence, a specific serum factor, the herpes gestationis factor. These ultrastructural and immunological data suggest a relationship between herpes gestationis and bullous pemphigus (Lever's disease). In treatment, the possible pathogenic role of prolactin suggests the use of bromocriptin during the postpartum period. The efficacy and innocuity of vitamin B6 make corticosteroids rarely necessary.

Adult↗
PubMed1982

Two anatomoclinical types of warts with plantar localization: specific cytopathogenic effects of papillomavirus. Type I (HPV-1) and type 2 (HPV-2).

In this study, the clinical and histopathological aspects of 50 plantar warts are reported in relation to the type of papillomavirus present in the lesions, as detected by immunofluorescence tests, using specific guinea pig fluorescein-labelled IgG. Warts of plantar localization are not caused by the same human papillomavirus (HPV) since they are found to be associated with both HPV type 1 (HPV-1) and HPV type 2 (HPV-2). HPV-1 is always associated with deep and painful plantar warts (myrmecia), whereas HPV-2 is found to be associated with superficial, painless plantar warts (vulgaris or often mosaic type). Histologically, these two types of plantar warts are quite different. In myrmecia (HPV-1), characterized by an endophytic growth, large eosinophilic, keratohyaline-like granules are observed in the cytoplasm and nucleus of infected, often vacuolated cells. These granules appear early in stratum spinosum and are very numerous in stratum granulosum. In the mosaic type (HPV-2), the histopathological aspect is not different from that of common warts; these lesions have an exophytic growth and are characterized by foci of clear vacuolized cells which are found in stratum granulosum. Their cytoplasm contains round, basophilic keratohyalin granules which often have a heterogenous aspect. These differences are observed in other localizations of morphologically related warts associated with HPV-1 and HPV-2 and seem to be related to a specific cytopathogenic effect of HPV-1 an HPV-2 in human papillomas.

Cytopathogenic Effect, Viral↗
PubMed1982

[Papular mucinosis associated with lupus erythematosus. A case presentation and review of the literature].

A 36-year-old woman presented with a widespread papulonodular eruption followed by cutaneous and systemic manifestations of lupus erythematosus. Both conditions, papular mucinosis and lupus erythematosus were investigated by histopathology, immunofluorescence and electron microscopy. Referring to seven other cases reported in the literature, the possible relationship between lupus erythematosus and cutaneous mucinosis is discussed. It seemed that the cutaneous deposits of mucine were secondary to lupus erythematosus and not a simultaneous occurrence of the two diseases.

Adult↗
PubMed1981

Isolation of rubella virus from synovial fluid in five cases of seronegative arthritis.

A cytopathic agent indistinguishable from rubella virus was isolated from the synovial fluid of five patients (two male and three female). In two patients isolations were made on two separate occasions, and in two others on five separate occasions. The patients ranged in age from 9-58 years, and they presented with a variety of clinical syndromes. In particular, none had clinical features suggestive of recent rubella infection; but most cases had very high serum rubella haemagglutination inhibition titres. The identity of the cytopathic agent was shown by a variety of virological techniques to be rubella virus.

Adult↗