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Biomedical subjects

M Melis

Publications and source records attributed to M Melis.

At least 73 records · Page 4Linked to original sources
PubMed1993

Influence of labour on epidermal growth factor receptor distribution of the human chorion at term gestation.

Chorion was obtained from 10 healthy pregnant women at term gestation who were delivered either vaginally (n = 5) or by elective repeat caesarean section before the onset of labour (n = 5). Epidermal growth factor (EGF) receptors in chorionic tissue were evaluated by means of freeze fracture technique (label fracture). They were found to be significantly less, but more frequently coupled, in specimens obtained after labour than before the onset of labour. These findings suggest that a functional activation of EGF receptors in human chorion might occur during labour.

Binding Sites↗
PubMed1993

[Deltamethrin-piperonyl butoxide (Launol) in the treatment of scabies. Clinical experience with 33 patients].

Deltametrin is an effective but not well tolerated treatment of scabies. The association with piperonil-butoxide allows shorter treatment periods, thereby reducing its adverse effects. We used this combination in the treatment of 33 patients with active scabies. Two treatment modalities were used with four or five applications, during 7 or 8 days respectively and patients were assessed two weeks later. Treatment was effective and well tolerated in 32 of the 33 patients and no differences were observed between the two modalities. It is concluded that this is an effective therapy for scabies.

Adolescent↗
PubMed1993

[Dissecting pseudomembranous celiocytic vaginitis caused by HPV in a HIV positive patient].

The Authors describe a case of dessicant pseudomembranous vaginitis caused by HPV types 6, 11, 16 and 18 in a 44-year-old HIV seropositive woman. A material mixed with blood, simulating a spontaneous abortion because of its quantity and consistency, was ejected vaginally. A spontaneous abortion was excluded on the basis of a pelvic echographic exam and on the beta-HCG plasma level. Histologic examination of the ejected material demonstrated an epithelium of the vaginal mucosa in which was found a marked and extensive koilocytosis of intermedial and parabasal layers. The vaginal mucosa in this patient differed from the commonly observed koilocytosis and condylomatous proliferation histological aspects seen in vaginal HPV lesions. In the context of the epithelium, by means of confluence of voluminous koilocytotic elements, pseudocystic lacunar spaces of varying dimensions definable as "koilocytotic pseudocysts" were observed. Within the vaginal epithelium, along a line of reduced resistance, a massive and extensive dessication resulted in a laminar detachment of the overlying epithelial stratum. Regarding the association between HIV and HPV infection, it is known that seropositive patients with immunodeficiencies are at high risk of infection by a variety of pathogens and, among these, different types of HPV. The viral association in this case undoubtedly promoted the extension and seriousness of the lesion and its exceptional complication.

AIDS-Related Opportunistic Infections↗
PubMed1993

Cytoprotective drugs in the prevention of ethanol-induced experimental gastric mucosal damage: a morphological study.

Various so-called "cytoprotective" agents (sucralfate, carbenoxolone, 16,16-dimethyl-PGE2, sulglycotide and Maalox TC) have been tested on rats, with the aim of quantifying their capability to prevent ethanol-induced gastric mucosal damage. Rats fasted for 48 hours received 1 ml of 80% ethanol by oral gavage, after prior oral treatment with placebo or one of the above-mentioned drugs u.i.d. for 5 consecutive days. Six hours after ethanol administration, the animals were sacrificed and the stomach was removed and processed for computerized macroscopic assessment of the damaged surface and for structural (light microscopy) and ultrastructural (scanning and transmission electron microscopy) studies. The results obtained demonstrate that ethanol injury caused extensive mucosal necrosis of the glandular region of the stomach, an event that was effectively reduced in rats treated with 16,16-dm-PGE2, carbenoxolone or sulglycotide. These drugs appeared to preserve the mucosa, with morphology comparable to that of normal noninjured rats - in contrast to the other drugs investigated. These data confirm the cytoprotective properties of sulglycotide in particular, which was the most potent agent for preventing the development of ethanol-induced acute lesions of the gastric mucosa.

16,16-Dimethylprostaglandin E2↗
PubMed1992

The monoclonal antibody ER-BMDM1 recognizes a macrophage and dendritic cell differentiation antigen with aminopeptidase activity.

Here we describe the reactivity of monoclonal antibody (mAb) ER-BMDM1, directed against a 160-kDa cell membrane-associated antigen (Ag) with amino-peptidase activity. The aminopeptidase recognized by ER-BMDM1 is present on various mouse macrophage (M phi) and dendritic cell (DC) subpopulations as well as on microvillous epithelia. Analysis of ER-BMDM1 Ag expression in in vitro models of M phi maturation revealed that the Ag is expressed at increasing levels upon maturation of M phi. In vivo, high level expression of the ER-BMDM1 Ag occurs after the monocytic stage of maturation, since bone marrow cells and peripheral blood monocytes are essentially ER-BMDM1 negative. Analysis of isolated-resident and elicited M phi populations showed that ER-BMDM1 recognizes a specific subpopulation of mature M phi: only some resident peritoneal and alveolar M phi are ER-BMDM1 positive, whereas virtually all thioglycollate-elicited peritoneal exudate M phi bind the mAb. In lymphoid organs, a subpopulation of M phi is recognized as well as interdigitating cells (IDC) located in T cell areas. Phenotypic analysis of isolated DC--the in vitro equivalents of IDC--from spleen and lymph nodes confirmed that the majority of this important antigen-presenting cell population expresses the ER-BMDM1 aminopeptidase. The molecular characteristics of the ER-BMDM1 Ag suggest that it may represent the mouse homolog of human CD13.

Aminopeptidases↗
PubMed1992

Antitumour activity of mononuclear phagocytes: role of tumour necrosis factor alpha.

Tumour necrosis factor alpha (TNF) is a cytokine produced by mononuclear phagocytes (MP) originally discovered for its cytotoxic activity on tumour cell targets. It was subsequently demonstrated that, in addition to its oncolytic potential, TNF exerts a wide variety of activities on the host defensive system against malignancies. This article briefly reviews the current concepts on the role of TNF in the antitumour activity of MP.

Cytotoxicity, Immunologic↗
PubMed1991

High-performance liquid chromatographic determination of dinitroaniline herbicides in soil and water.

A high-performance liquid chromatographic method for the simultaneous determination of the dinitroaniline herbicides dinitramine, ethalfluralin, trifluralin, pendimethalin and isopropalin in soil and surface water is reported. The soil was extracted with diethyl ether and analysed without any clean-up. The water was analysed after purification and concentration on a C18 cartridge. The average recoveries were in the range 89-104%. The detection limits for the five herbicides were 0.02 mg/kg in dry soil and 0.5 micrograms/l in surface water.

Aniline Compounds↗
PubMed1991

Effect of indomethacin on the kinetics of tumour necrosis factor alpha release and tumour necrosis factor alpha gene expression by human blood monocytes.

In this investigation we have examined the effects of indomethacin, an inhibitor of the cyclooxygenase pathway of arachidonic acid, upon the kinetics of the release of tumour necrosis factor alpha (TNF) and of the expression of TNF gene by lipopolysaccharide (LPS)-stimulated human blood monocytes (BM). Following stimulation of BM with LPS, TNF was released within 2 h, reached peak values at 8 h and declined at subsequent time-points (24 and 48 h). Indomethacin (10(-5) M) slightly stimulated the production of TNF at 2, 4, and 8 h and prevented the decline of TNF observed at 24 and 48 h. This effect was related to the persistence of TNF synthesis, as demonstrated by kinetic evaluation of the expression of TNF gene performed by dot-blot analysis. The effects of indomethacin on TNF release and TNF gene expression were due to the inhibition of endogenous prostaglandin (PG)E2 production. In the absence of indomethacin, PGE2 release by the LPS-stimulated BM began concomitantly with the decline of TNF production by the same cells under the same stimulus. Indomethacin completely blocked PGE2 release at any time-point. Exogenous PGE2 suppressed the release of TNF and the expression of TNF gene in a dose-dependent fashion. Exogenous PGE2 completely reversed the effects of indomethacin on TNF production at 24 h. These findings suggest that indomethacin may significantly alter the kinetics of TNF release and TNF gene expression by LPS-stimulated BM. These effects are related, at least in part, to the inhibition of the production of endogenous PGE2, an important self-driven regulatory factor of the kinetics of TNF production.

Dinoprostone↗
PubMed1991

Increased expression of leukocyte function associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) by alveolar macrophages of patients with pulmonary sarcoidosis.

Leukocyte function associated antigen-1 (LFA-1) and its ligand intercellular adhesion molecule-1 (ICAM-1) are cell adhesion molecules that play an important role in the capacity of monoculear phagocytes (MPs) to present antigens to T lymphocytes. Since in pulmonary sarcoidosis (PS) this capacity is increased at sites of disease activity, we studied the expression of LFA-1 and ICAM-1 on peripheral blood monocytes (BMs) and alveolar macrophages (AM) obtained by bronchoalveolar lavage (BAL) from normal subjects (n = 7) and patients with PS (n = 14). To accomplish this, immunocytochemical stainings were made on cytocentrifuge preparations using anti-LFA-1 (anti-CD 11a) and anti-ICAM-1 (anti-CD 54) monoclonal antibodies (MoAbs). Normal and sarcoid BMs displayed a high percentage of positivity with both MoAbs with no difference between study groups (LFA-1: control BM 87.8 +/- 8.8 percent; sarcoid BM 84.7 +/- 9.5 percent; ICAM-1: control BM 80.8 +/- 10 percent; sarcoid BM 88.0 +/- 4.2 percent; p = NS for all comparisons). In both groups the percentage of cells expressing LFA-1 and ICAM-1 molecules among AMs was lower than among autologous BMs (LFA-1: control AM 46.5 +/- 13.2 percent, p less than 0.001 vs control BM; sarcoid AM 64.2 +/- 15.9; p less than 0.001 vs sarcoid BM) (ICAM-1: control AM 42.7 +/- 8.5 percent, p less than 0.001 vs control BM; sarcoid AM 72.1 +/- 10.6, p less than 0.001 vs sarcoid BM). AMs from patients with PS showed a higher degree of positivity for LFA-1 and ICAM-1 than normal AMs (p less than 0.02 and p less than 0.001, respectively). The positivity for LFA-1 and ICAM-1 molecules on sarcoid AMs was not correlated with the positivity for two different BM-associated markers (ie, the CD 11b and the CD 14 molecules) and was not correlated with the percentage of T lymphocytes in BAL, selected as a marker of the intensity of the alveolitis. These results suggest that the increased ability of sarcoid AMs to induce the proliferation of T lymphocytes may be related, at least in part, to the increased expression of LFA-1 and ICAM-1 molecules on their surfaces.

Antigen-Presenting Cells↗
PubMed1991

Scanning electron microscopy observations of nasal mucosa in patients affected by retinitis pigmentosa.

A controlled study of the ciliated epithelium of olfactory mucosa was performed on 25 patients affected by retinitis pigmentosa and in 5 healthy subjects. Scanning Electron Microscopy showed a significant lack of ciliated epithelial cells. These cells probably represent undifferentiated ciliated cells. These morphological alterations of the olfactory mucosa might correspond to similar changes in the outer segment of retinal photoreceptors in retinitis pigmentosa.

Humans↗
PubMed1991

[Monitoring of erection function in patients with prostatic carcinoma treated with Casodex].

This study evaluates the sleep-related erections in 5 patients with locally advanced prostate cancer (T3NOMO) during 6 months treatment with Casodex by multinight continuous monitoring of penile tumescence and rigidity. Mean serum LH, Testosterone and Estradiol levels shown a no statistically significant increase at the six months control. We found no significant modifications in the number of NPT episodes, maximum penile circumference and rigidity time before and after therapy. Penile arterial flow and neurologic examination were also unmodified. All patients had a stable disease and unchanged performance status after 6 months. This pure antiandrogen in a men with prostate cancer does not seem to interfere with self reported libido and erectile capability.

Androgen Antagonists↗
PubMed1990

Determination of heavy metals in animal tissues.

During studies on the accumulation of heavy metals in animal organs and tissues, only small samples (0.5-2 g) rich in lipids and having low concentrations of metals are often available. This may lead to loss of metals in the various steps of the analytical procedure. A modified procedure of mineralization for the determination of Pb, Cd and Zn is described, as well as suitable analytical procedures used by the Authors for the determination by atomic absorption spectrophotometry. Results showed that the loss of metals is minimized with these procedures.

Animals↗
PubMed1990

Murine macrophage precursor characterization. I. Production, phenotype and differentiation of macrophage precursor hybrids.

This study reports on the earliest stages of mononuclear phagocyte differentiation. A crucial question in this developmental process is whether mature macrophage (M phi) heterogeneity is already appointed at the precursor cell level. For this purpose, we produced clonal populations of mononuclear phagocytes from bone marrow culture by somatic cell hybridization with two hypoxanthine, aminopterin, thymidine-sensitive myeloid cell lines. A panel of 22 stable hybrids was obtained from these fusions. Differentiation stage analysis of the hybrids indicated that all cell lines had immature mononuclear phagocyte characteristics. The hybrids exhibited typical myeloid morphology and mainly nonadherent growth. Mature M phi features, such as expression of the cell surface antigens Mac-1, Mac-2 and F4/80, phagocytosis of latex beads, and expression of nonspecific esterase and acid phosphatase activity, were virtually absent. The immature M phi markers Thy-1, MIV25 and MIV52, on the other hand, were readily expressed, although heterogeneity was observed among different hybrid cell lines. We then analyzed the differentiation potential of seven hybrids by culture of the cells in the presence of post-lipopolysaccharide serum supplemented with interferon-gamma and found that the expression of mature M phi characteristics was induced. However, the various hybrids showed divergent patterns of mature M phi marker induction. R0C2 cells, for instance, showed extensive morphological and phenotypical differentiation without concomitant induction of phagocytosis. In contrast, W1C4 cells showed significant induction of phagocytosis without simultaneous increase of phosphatase and esterase activity. R1C1 cells were unique in the strong induction of Ia antigen expression. Together, our data indicate that (a) early M phi differentiation stages can be rescued by somatic cell hybridization, and that (b) the obtained cell lines are able to mature according to divergent differentiation programs.

Acid Phosphatase↗
PubMed1990

Murine macrophage precursor characterization. II. Monoclonal antibodies against macrophage precursor antigens.

The aim of the present study was the phenotypical analysis of early stages in macrophage (M phi) differentiation. For this purpose, we produced a panel of syngeneic rat hybridomas, which secreted antibodies (mAb) against M phi precursor antigens. As immunogens we used immortalized M phi precursors (P.J. M. Leenen et al., Eur. J. Immunol. 1990, 20: 15). We screened the obtained mAb in the following in vitro models of M phi differentiation: (a) a panel of M phi cell lines ordered in a linear differentiated sequence; (b) immature and mature mononuclear phagocytes obtained from bone marrow (BM) culture; (c) a panel of M phi precursor hybrids, and (d) differentiated and control M phi precursor hybrid cells. Four mAb, ER-MP12, ER-MP20, ER-MP54 and ER-MP58, were selected. These mAb recognize antigens which disappear in the course of M phi differentiation. Next, we investigated whether these mAb also recognized M phi precursors in normal BM. For this purpose, ER-MP-positive and -negative BM fractions were isolated using a fluorescence-activated cell sorter. Fractions were cultured in M phi-colony-stimulating factor-containing conditioned medium, and the resulting mature M phi progeny was quantified using the MTT assay. The present experiments indicate that ER-MP12 and ER-MP20 detect a subpopulation of BM M phi precursors, whereas ER-MP58 stains virtually all M phi precursors. Biochemical analysis of radioiodinated antigens revealed that these mAb recognize different molecules. ER-MP12 and ER-MP20 bound to single-chain (glyco)proteins of 140 kDa and 14 kDa, respectively. ER-MP54 precipitated multiple polypeptides, of which the major chains have an apparent molecular mass of 90, 80-85 and 70-75 kDa. Based on the molecular mass of the recognized antigens and the mAb specificities we conclude that ER-MP12, ER-MP54 and ER-MP58 recognize hitherto unknown antigens of murine M phi precursor cells. The antigen detected by ER-MP20 is most likely identical to Ly-6C.

Animals↗
PubMed1990

Differential inhibition of macrophage proliferation by anti-transferrin receptor antibody ER-MP21: correlation to macrophage differentiation stage.

Monoclonal antibodies (mAbs) directed against the transferrin receptor are known to inhibit proliferation of cells due to iron deprivation. Some cell types, however, escape from growth inhibition by a mechanism which is unclear at present. This mechanism is the subject of the present study. We investigated the differential growth inhibition caused by anti-transferrin receptor mAb ER-MP21 in connection with the differentiation of murine macrophages (M phi). Therefore, we applied two models of M phi differentiation, namely, culture of bone marrow cells in the presence of M-CSF and a panel of M phi cell lines ordered in a linear differentiation sequence. In both models we observed that proliferation of M phi precursors was strongly inhibited by ER-MP21. In contrast, proliferation of more mature stages of M phi differentiation was hardly affected. Remarkably, iron uptake by M phi precursor and mature M phi cell lines was inhibited by ER-MP21 to the same extent. However, mature M phi cell lines showed an iron uptake two- to threefold higher than that of M phi precursor cell lines. These observations strongly suggest that mature M phi escape from ER-MP21-mediated growth inhibition, because these cells take up more iron than is actually needed for proliferation. Furthermore, we found that enhanced iron uptake by mature M phi is not necessarily accompanied by a higher cell surface expression of transferrin receptors, thus suggesting an increased recycling of transferrin receptors in mature M phi.

Animals↗