RÉSUMÉ
To evaluate the effect of body mass on the hormonal and semen profiles of subfertile men with oligozoospemia, sperm concentration and reproductive hormone levels were compared in two body mass index (BMI) groups: underweight or normal weight patients (BMI = 25 kg/m2) vs. overweight or obese patients (BMI > 25 kg/m2). The mean BMI was 27 +/- 4.6 kg/m2. The testosterone/estradiol ratio was significantly reduced in the high BMI group as compared to the low BMI group (17 +/- 4 vs. 12 +/- 3; p < 0.05). A similar difference was found in the sperm concentration (11.2 +/- 3.16 x 10(6)/ml vs. 8.1 +/- 2.6 x 10(6)/ml). A nonsignificant difference was found in the LH/FSH ratio (1.41 +/- 0.64 vs. 1.63 +/- 0.72). We concluded that obesity and the consequent estrogen excess decrease the sperm concentration by influencing the hypothalamo-pituitary system.
Sujet(s)
Poids/physiologie , Oestradiol/métabolisme , Oligospermie/physiopathologie , Testostérone/métabolisme , Adulte , Indice de masse corporelle , Hormone folliculostimulante/métabolisme , Humains , Hormone lutéinisante/métabolisme , Mâle , Obésité/complications , Oligospermie/étiologieRÉSUMÉ
The aim of this study was to examine the relationship of semen parameters, sexual function-related hormones and waist/hip ratio. Eighty-one selected patients presenting with infertility were examined. Weight, height, waist circumference and hip circumference were measured, and reproduction-related hormone levels were determined. Semen was analysed by conventional methods. Semen volume, sperm concentration, motility, total sperm count, total motile sperm cell number, rapid progressive motile sperm count and reproduction-related hormone levels [follicle-stimulating hormone, luteinizing hormone, prolactin, testosterone, 17beta-oestradiol and sexual hormone-binding globulin (SHBG)]. Significant correlations were found: (i) weight, waist circumference and hip circumference versus testosterone level, SHBG level, and testosterone/17beta-oestradiol ratio; (ii) hip circumference versus sperm concentration; (iii) waist circumference and hip circumference versus sperm count, total motile sperm cell number and rapid progressive motile sperm count; (iv) weight versus total sperm count and total motile sperm cell number; (v) waist circumference and hip circumference versus prolactin level (positively) and SHBG (negatively); (vi) waist circumference and waist/hip ratio versus semen volume. It can be concluded that the waist/hip ratio is correlated with the reproductive hormone levels. Although both the waist circumference and hip circumference correlated with the semen characteristics, the waist/hip ratio did not.
Sujet(s)
Répartition du tissu adipeux , Infertilité masculine/physiopathologie , Sperme/physiologie , Mobilité des spermatozoïdes/physiologie , Adulte , Indice de masse corporelle , Oestradiol/sang , Humains , Mâle , Adulte d'âge moyen , Prolactine/sang , Globuline de liaison aux hormones sexuelles/analyse , Numération des spermatozoïdes , Testostérone/sangRÉSUMÉ
This study was conducted to determine a possible relationship between regular cell phone use and different human semen attributes. The history-taking of men in our university clinic was supplemented with questions concerning cell phone use habits, including possession, daily standby position and daily transmission times. Semen analyses were performed by conventional methods. Statistics were calculated with SPSS statistical software. A total of 371 were included in the study. The duration of possession and the daily transmission time correlated negatively with the proportion of rapid progressive motile sperm (r = -0.12 and r = -0.19, respectively), and positively with the proportion of slow progressive motile sperm (r = 0.12 and r = 0.28, respectively). The low and high transmitter groups also differed in the proportion of rapid progressive motile sperm (48.7% vs. 40.6%). The prolonged use of cell phones may have negative effects on the sperm motility characteristics.
Sujet(s)
Téléphones portables , Sperme/physiologie , Mobilité des spermatozoïdes/physiologie , Adolescent , Adulte , Sujet âgé , Humains , Mâle , Adulte d'âge moyen , Numération des spermatozoïdesRÉSUMÉ
A total of 274 men (aged: 26 +/- 4.9 years) with normozoospermia were enrolled into this study. Their body mass index (BMI: kg/m2) varied between 17 and 39. According to BMI, the patients were divided into four groups: Group 1: 17-20, Group 2: 20.1-25, Group 3: 25.1-30 and Group 4: 30.1-39. Twenty-nine subjects were found in the first, 96 in the second, 91 in the third and 58 men in the fourth group. Sperm concentration was significantly lower in the obese group (29 x 10(6)/ml, p < 0.05) than in the group of BMI 17-20, 20-25 and 25-30. In advance, in the obese group, sperm count continuously decreased with aging. We conclude that obesity is associated with a lower sperm count in case of normozoospermia.
Sujet(s)
Poids , Numération des spermatozoïdes , Adolescent , Adulte , Vieillissement , Indice de masse corporelle , Enfant , Humains , Mâle , Adulte d'âge moyen , Obésité/physiopathologie , Valeurs de référenceRÉSUMÉ
The fluid mosaic membrane model proved to be a very useful hypothesis in explaining many, but certainly not all, phenomena taking place in biological membranes. New experimental data show that the compartmentalization of membrane components can be as important for effective signal transduction as is the fluidity of the membrane. In this work, we pay tribute to the Singer-Nicolson model, which is near its 30th anniversary, honoring its basic features, "mosaicism" and "diffusion," which predict the interspersion of proteins and lipids and their ability to undergo dynamic rearrangement via Brownian motion. At the same time, modifications based on quantitative data are proposed, highlighting the often genetically predestined, yet flexible, multilevel structure implementing a vast complexity of cellular functions. This new "dynamically structured mosaic model" bears the following characteristics: emphasis is shifted from fluidity to mosaicism, which, in our interpretation, means nonrandom codistribution patterns of specific kinds of membrane proteins forming small-scale clusters at the molecular level and large-scale clusters (groups of clusters, islands) at the submicrometer level. The cohesive forces, which maintain these assemblies as principal elements of the membranes, originate from within a microdomain structure, where lipid-lipid, protein-protein, and protein-lipid interactions, as well as sub- and supramembrane (cytoskeletal, extracellular matrix, other cell) effectors, many of them genetically predestined, play equally important roles. The concept of fluidity in the original model now is interpreted as permissiveness of the architecture to continuous, dynamic restructuring of the molecular- and higher-level clusters according to the needs of the cell and as evoked by the environment.
Sujet(s)
Membrane cellulaire/physiologie , Fluidité membranaire , Modèles biologiques , Animaux , Membrane cellulaire/composition chimique , Phénomènes chimiques , Chimie physique , Diffusion , Transfert d'énergie par résonance de fluorescence , Double couche lipidique , Lipides membranaires/physiologie , Microdomaines membranaires/physiologie , Protéines membranaires/physiologie , Microscopie électronique , Transduction du signalRÉSUMÉ
A total of 1,144 infertile women were treated by artificial donor insemination. Unsuccessful ovulation induction was found in 96 of these cases. The obese women (BMI: 28-36) had a relative risk of unsuccessful ovulation induction of 2.7 (95% confidence interval (CI) = 2.1-3.4) compared with women lower or normal body weight (BMI: 20-24). The effect was smaller in women with a BMI 25-27 or < 19 (relative risk (RR) = 1.4, 95% CI = 0.9-2.1 and 1.5, 95% CI = 0.8-2.5), respectively. During the AID treatment 412 pregnancies occurred. Pregnancy rate achieved by insemination was 28% (50 pregnancies per 178 cases, BMI 16-19), 42% (251/599, BMI 20-24), 33% (92/286, BMI 25-27), and 21% (19/81, BMI 28-36), respectively, in the different BMI groups.
Sujet(s)
Poids , Insémination artificielle avec donneur , Indice de masse corporelle , Femelle , Humains , Obésité , Grossesse , Issue de la grossesse , SuperovulationRÉSUMÉ
Endometriosis is one of the most frequent benign diseases in gynecology. It is the cause of the pelvic pain and infertility in more than 35% of women of reproductive age. The most appropriate treatment for endometriosis is the combination of surgery and adjuvant medical therapy with GnRH agonists. The authors demonstrate the results of 33 artificial intrauterine homolog inseminations after a 6-month GnRH analog therapy.
Sujet(s)
Endométriose/traitement médicamenteux , Hormone de libération des gonadotrophines/usage thérapeutique , Insémination artificielle avec conjoint , Adulte , Dysménorrhée/étiologie , Dyspareunie/étiologie , Endométriose/complications , Endométriose/diagnostic , Femelle , Humains , Infertilité féminine/étiologie , Infertilité féminine/thérapie , Laparoscopie , GrossesseRÉSUMÉ
The glycosylphosphatidylinositol-anchored receptor CD14 plays a major role in the inflammatory response of monocytes to lipopolysaccharide. Here, we describe that ceramide, a constituent of atherogenic lipoproteins, binds to CD14 and induces clustering of CD14 to co-receptors in rafts. In resting cells, CD14 was associated with CD55, the Fcgamma-receptors CD32 and CD64 and the pentaspan CD47. Ceramide further recruited the complement receptor 3 (CD11b/CD18) and CD36 into proximity of CD14. Lipopolysaccharide, in addition, induced co-clustering with Toll-like receptor 4, Fcgamma-RIIIa (CD16a) and the tetraspanin CD81 while CD47 was dissociated. The different receptor complexes may be linked to ligand-specific cellular responses initiated by CD14.
Sujet(s)
Céramides/métabolisme , Protéines de Drosophila , Antigènes CD14/métabolisme , Lipopolysaccharides/pharmacologie , Microdomaines membranaires/métabolisme , Protéines membranaires , Monocytes/métabolisme , Antigènes CD/métabolisme , Antigènes CD47 , Protéines de transport/métabolisme , Humains , Inflammation/métabolisme , Ligands , Antigène macrophage 1/métabolisme , Glycoprotéines membranaires/métabolisme , Récepteurs de surface cellulaire/métabolisme , Antigène CD81 , Récepteur de type Toll-4 , Récepteurs de type TollRÉSUMÉ
The existence of small- and large-scale membrane protein clusters, containing dimers, oligomers and hundreds of proteins, respectively, has become widely accepted. However, it is largely unknown whether the internal structure of these formations is dynamic or static. Cell fusion was used to perturb the distribution of existing membrane protein clusters, and to investigate their mobility and associations. Scanning near-field optical microscopy, confocal and electron microscopy were applied to detect the exchange of proteins between large-scale protein clusters, whereas photobleaching fluorescence energy transfer was used to image the redistribution of existing small-scale membrane protein clusters. Large-scale clusters of major histocompatibility complex (MHC)-I exchanged proteins with each other and with MHC-II clusters. Similarly to MHC-I, large-scale MHC-II clusters were also dynamic. Exchange of components between small-scale protein clusters was not universal: intermixing did not take place in the case of MHC-II homoclusters; however, it was observed for homoclusters of MHC-I and for heteroclusters of MHC-I and MHC-II. These processes required a fluid state of the plasma membrane, and did not depend on endocytosis-mediated recycling of proteins. The redistribution of large-scale MHC-I clusters precedes the intermixing of small-scale clusters of MHC-I indicating a hierarchy in protein association. Investigation of a set of other proteins (alpha subunit of the interleukin 2 receptor, CD48 and transferrin receptor) suggested that a large-scale protein cluster usually exchanges components with the same type of clusters. These results offer new insight into processes requiring time-dependent changes in membrane protein interactions.
Sujet(s)
Fusion cellulaire , Antigènes d'histocompatibilité de classe II/métabolisme , Antigènes d'histocompatibilité de classe I/métabolisme , Agrégation des récepteurs/physiologie , Récepteurs de surface cellulaire/métabolisme , Lignée cellulaire , Membrane cellulaire/composition chimique , Membrane cellulaire/métabolisme , Transfert d'énergie , Colorants fluorescents/métabolisme , Or colloïdal/métabolisme , Humains , Microdomaines membranaires , Microscopie , Microscopie de fluorescence/méthodes , Récepteurs à l'interleukine-2RÉSUMÉ
BACKGROUND: A multicentre epidemiological survey was carried out in order to determine the prevalence of, and risk factors for, persistent cervical human papillomavirus (HPV) infection in women in Hungary. METHODS AND RESULTS: A total of 728 women were examined for the prevalence of HPV. The estimated overall rate of HPV infection was 17%. In univariate analysis the strongest predictors were young age (< or =24 years), unmarried family status, smoking, a pathological Papanicolaou (Pap) smear, having a condyloma and previous gynaecological cancer in the family (age and marital status being the most important predictors). In multiple regression analysis, young age (< or =24 years)(odds ratio = 1.86, 95% confidence interval = 1.19-2.90, P < 0.01), smoking (1.78, 1.17-2.71, P < 0.05), an abnormal Pap smear (6.92, 2.68-17.84, P < 0.001), having a condyloma (4.22, 1.42-12.58, P < 0.01) and living in a region where the unemployment rate is relatively high (1.56, 1.24-2.82, P < 0.01) were associated risk factors for HPV infection. CONCLUSIONS: The prevalence of HPV infection in young women in Hungary is high. Screening for HPV is suggested only in women with an unfavourable gynaecological history who are < or =24 years old.
Sujet(s)
Dépistage de masse , Infections à papillomavirus/diagnostic , Infections à virus oncogènes/diagnostic , Adulte , Études transversales , Femelle , Enquêtes de santé , Humains , Hongrie , Papillomaviridae , Infections à papillomavirus/épidémiologie , Infections à papillomavirus/étiologie , Prévalence , Facteurs de risque , Infections à virus oncogènes/épidémiologie , Infections à virus oncogènes/étiologieRÉSUMÉ
Fluorescence resonance energy transfer (FRET) data, in accordance with lateral mobility measurements, suggested the existence of class I HLA dimers and oligomers at the surface of live human cells, including the B lymphoblast cell line (JY) used in the present study. Intra- and intermolecular class I HLA epitope distances were measured on JY B cells by FRET using fluorophore-conjugated Ag-binding fragments of mAbs W6/32 and L368 directed against structurally well-characterized heavy and light chain epitopes, respectively. Out-of-plane location of these epitopes relative to the membrane-bound BODIPY-PC (2-(4,4-difluoro-5-(4-phenyl-1,3-butadienyl)-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-1-hexadecanoyl-sn-glycero-3-phosphocholine) was also determined by FRET. Computer-simulated docking of crystallographic structures of class I HLA and epitope-specific Ag-binding fragments, with experimentally determined interepitope and epitope to cell surface distances as constraints, revealed several sterically allowed and FRET-compatible class I HLA dimeric and tetrameric arrangements. Extension of the tetrameric class I HLA model with interacting TCR and CD8 resulted in a model of a supramolecular cluster that may exist physiologically and serve as a functionally significant unit for a network of CD8-HLA-I complexes providing enhanced signaling efficiency even at low MHC-peptide concentrations at the interface of effector and APCs.
Sujet(s)
Antigènes CD8/composition chimique , Transfert d'énergie/immunologie , Antigènes HLA/composition chimique , Antigènes d'histocompatibilité de classe I/composition chimique , Modèles moléculaires , Récepteurs aux antigènes des cellules T/composition chimique , Cellules présentatrices d'antigène/composition chimique , Cellules présentatrices d'antigène/immunologie , Lymphocytes B/composition chimique , Lymphocytes B/immunologie , Lignée de cellules transformées , Membrane cellulaire/composition chimique , Membrane cellulaire/immunologie , Simulation numérique , Cristallographie aux rayons X/méthodes , Déterminants antigéniques des lymphocytes B/composition chimique , Antigène HLA-A2/composition chimique , Humains , Fragments Fab d'immunoglobuline/composition chimique , Cartographie peptidique , Spectrométrie de fluorescence/méthodes , bêta-2-Microglobuline/composition chimiqueRÉSUMÉ
Streptomyces strains isolated from the Kuwait Burgan oil field were defined as S. griseoflavus, S. parvus, and S. plicatus utilised n-hexadecane, n-octadecane (purified fractions of mineral oil), kerosene, and crude oil as sole carbon and energy sources. The strains were incubated with n-alkanes and increase of the fatty acid content with chain length equivalent to the employed n-alkanes was observed. Signal transducing GTP-binding proteins (GBPs) play an important role in n-alkane uptake in streptomycetes. Specific activators of GBPs increased the uptake of hydrocarbons. Using the hydrophobic fluorescent dye diphenylhexatrien (DPH) as a probe, it was found that the microviscosity of the hydrophobic inner region of the cellular membrane is significantly lower in hydrocarbon utilisers than in non-utilisers. This difference probably reflects differences in the fatty acid composition of the strains. When cultures were grown in n-alkane containing media, electron microscopy revealed that the hydrocarbon utilisers showed less-electron dense areas as inclusions in the cytoplasm. Soil samples inoculated with Streptomyces strains eliminated hydrocarbons much faster than those not containing these strains, serving as control. When inorganic medium was supplied with n-hexadecane-1-14C as sole carbon and energy source, radioactive CO2 was detected. Since streptomycetes have not been used until now for oil elimination, though they are known as abundant soil bacteria tolerating extreme conditions, their possible use for bioremediation of hydrocarbon contaminated soils is discussed.
Sujet(s)
Alcanes/métabolisme , 1,6-Diphényl-hexa-1,3,5-triène/analogues et dérivés , Streptomyces/métabolisme , Dépollution biologique de l'environnement , Membrane cellulaire/composition chimique , Membrane cellulaire/physiologie , Perméabilité des membranes cellulaires , 1,6-Diphényl-hexa-1,3,5-triène/métabolisme , Acides gras/analyse , Colorants fluorescents/métabolisme , Protéines G/métabolisme , Hydrocarbures/métabolisme , Streptomyces/ultrastructureRÉSUMÉ
Immunogold staining and electron microscopy show that IL-2 receptor alpha-subunits exhibit nonrandom surface distribution on human T lymphoma cells. Analysis of interparticle distances reveals that this clustering on the scale of a few hundred nanometers is independent of the presence of IL-2 and of the expression of the IL-2R beta-subunit. Clustering of IL-2Ralpha is confirmed by confocal microscopy, yielding the same average cluster size, approximately 600-800 nm, as electron microscopy. HLA class I and II and CD48 molecules also form clusters of the same size. Disruption of cholesterol-rich lipid rafts with filipin or depletion of membrane cholesterol with methyl-beta-cyclodextrin results in the blurring of cluster boundaries and an apparent dispersion of clusters for all four proteins. Interestingly, the transferrin receptor, which is thought to be located outside lipid rafts, exhibits clusters that are only 300 nm in size and are less affected by modifying the membrane cholesterol content. Furthermore, transferrin receptor clusters hardly colocalize with IL-2Ralpha, HLA, and CD48 molecules (crosscorrelation coefficient is 0.05), whereas IL-2Ralpha colocalizes with both HLA and CD48 (crosscorrelation coefficient is between 0.37 and 0.46). This coclustering is confirmed by electron microscopy. The submicron clusters of IL-2Ralpha chains and their coclustering with HLA and CD48, presumably associated with lipid rafts, could underlie the efficiency of signaling in lymphoid cells.
Sujet(s)
Antigènes CD/analyse , Cholestérol/physiologie , Antigènes HLA/analyse , Lymphome T/anatomopathologie , Lipides membranaires/physiologie , Protéines tumorales/analyse , Récepteurs à l'interleukine-2/analyse , Lymphocytes T/métabolisme , Antigène CD48 , Humains , Immunohistochimie , Fluidité membranaire , Microscopie confocale , Microscopie immunoélectronique , Cellules cancéreuses en cultureRÉSUMÉ
Campath-1H, a humanized mAb undergoing clinical trials for treatment of leukemia, transplantation and autoimmune diseases, produces substantial lymphocyte depletion in vivo. The antibody binds to CD52, a highly glycosylated molecule attached to the membrane by a glycosylphosphatidylinositol anchor. Cross-linked Campath-1H is known to activate T cells in vitro. We have investigated the molecular basis for these effects by comparing the protein tyrosine phosphorylation signals induced by Campath-1H and the CD3 mAb OKT3 in primary T cells, and in CD45(+)TCR(+), CD45(-)TCR(+) and CD45(+)TCR(-) Jurkat subclones transfected with CD52. Our results show that Campath-1H triggers similar tyrosine phosphorylation events as OKT3 in both primary T cells and in the CD45(+)TCR(+) Jurkat sub-clone, albeit at quantitatively lower levels. However, no phospholipase C gamma 1 activation nor calcium signals were detected in response to CD52 ligation. The CD52-mediated induction of protein tyrosine phosphorylation was absolutely dependent upon the expression of both the TCR and the CD45 phosphotyrosine phosphatase at the cell surface. Cross-linking of Campath-1H was essential for signal transduction in all cells investigated. Fluorescence resonance energy transfer was used to demonstrate CD52 homo-association at the cell surface in Jurkat T cells in a TCR- and CD45-independent manner, and CD52-TCR association in CD45(+)TCR(+) cells. We propose a model to explain the activating effects of Campath-1H in which CD52 mAb cross-linking causes the trapping of TCR polypeptides within molecular complexes at the cell surface, thereby inducing signals via the TCR by a process which depends on the CD45-mediated regulation of the p56(lck) and p59(fyn) tyrosine kinases.
Sujet(s)
Anticorps monoclonaux/physiologie , Anticorps antitumoraux/physiologie , Antigènes CD/physiologie , Antigènes néoplasiques , Glycoprotéines/physiologie , Antigènes CD45/physiologie , Récepteurs aux antigènes des cellules T/physiologie , Transduction du signal/immunologie , Lymphocytes T/enzymologie , Lymphocytes T/immunologie , Alemtuzumab , Anticorps monoclonaux humanisés , Antigènes CD/métabolisme , Antigène CD52 , Calcium/physiologie , Signalisation calcique/immunologie , Cellules cultivées , Glycoprotéines/métabolisme , Humains , Inositol 1,4,5-trisphosphate/immunologie , Isoenzymes/immunologie , Cellules Jurkat , Phospholipase C gamma , Récepteurs aux antigènes des cellules T/métabolisme , Transduction du signal/génétique , Lymphocytes T/métabolisme , Transfection , Type C Phospholipases/immunologieRÉSUMÉ
Platelet function is influenced by the platelet thiol-disulfide balance. Platelet activation resulted in 440% increase in surface protein thiol groups. Two proteins that presented free thiol(s) on the activated platelet surface were protein-disulfide isomerase (PDI) and glycoprotein 1balpha (GP1balpha). PDI contains two active site dithiols/disulfides. The active sites of 26% of the PDI on resting platelets was in the dithiol form, compared with 81% in the dithiol form on activated platelets. Similarly, GP1balpha presented one or more free thiols on the activated platelet surface but not on resting platelets. Anti-PDI antibodies increased the dissociation constant for binding of vWF to platelets by approximately 50% and PDI and GP1balpha were sufficiently close on the platelet surface to allow fluorescence resonance energy transfer between chromophores attached to PDI and GP1balpha. Incubation of resting platelets with anti-PDI antibodies followed by activation with thrombin enhanced labeling and binding of monoclonal antibodies to the N-terminal region of GP1balpha on the activated platelet surface. These observations indicated that platelet activation triggered reduction of the active site disulfides of PDI and a conformational change in GP1balpha that resulted in exposure of a free thiol(s).
Sujet(s)
Plaquettes/métabolisme , Glycoprotéines de membrane plaquettaire/métabolisme , Protein Disulfide-Isomerases/sang , Anticorps/immunologie , Plaquettes/enzymologie , Membrane cellulaire/enzymologie , Membrane cellulaire/métabolisme , Humains , Masse moléculaire , Activation plaquettaire , Agrégation plaquettaire , Protein Disulfide-Isomerases/immunologie , Thiols/sang , Thiols/composition chimique , Facteur de von Willebrand/métabolismeRÉSUMÉ
The partition coefficient, surface activity and membrane fluidizing/disordering effects of CH-103, a beta-adrenergic receptor antagonist, were compared to those of propranolol and practolol as reference compounds. Changes in membrane fluidity were followed by measuring the steady-state fluorescence anisotropy of bull sperm cells with 1-[4-(trimethylammonium)-phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) as a fluorescence probe. The octanol/buffer (pH 7.0) partition coefficients for CH-103, propranolol and practolol were 32.9, 5.08 and 0.013, respectively; the surface activity of the compounds decreased in the same order. CH-103 and propranolol significantly increased the fluidity of the membrane in a concentration-dependent manner, whereas practolol reduced fluidity. These physicochemical parameters correlated with the effects of these drugs on rat sarcolemmal Ca2+, Mg(2+)-ATPase, a manifestation of their nonspecific membrane activity. Our results suggest that the physicochemical properties of CH-103, similarly to those of propranolol, are the main determinants of its nonspecific membrane activity.
Sujet(s)
Antagonistes bêta-adrénergiques/pharmacologie , Aminoalcools/pharmacologie , Fluidité membranaire/effets des médicaments et des substances chimiques , Practolol/pharmacologie , Propranolol/pharmacologie , Animaux , Bovins , Phénomènes chimiques , Chimie physique , Polarisation de fluorescence , Techniques in vitro , Mâle , Sperme/cytologie , Sperme/effets des médicaments et des substances chimiques , Propriétés de surface , Tension superficielleRÉSUMÉ
ErbB2 (HER2, Neu), a member of the epidermal growth factor (EGF) receptor tyrosine kinase family, is often overexpressed in breast cancer and other malignancies. ErbB2 homodimerizes but also presents as a common auxiliary subunit of the EGF and heregulin receptors (erbB1 or EGFR; and erbB3-4, respectively), with which it heteroassociates. ErbB2 is generally regarded as an orphan (ligand-less) receptor with a very potent kinase domain activated either via its associated partners or constitutively as a consequence of discrete mutations. It follows that the extent and regulation of its cell surface interactions are of central importance. We have studied the large-scale association pattern of erbB2 in quiescent and activated cells labeled with fluorescent anti-erbB2 monoclonal antibodies using scanning near-field optical microscopy (SNOM). ErbB2 was found to be concentrated in irregular membrane patches with a mean diameter of approx. 0.5 microm in nonactivated SKBR3 and MDA453 human breast tumor cells. The average number of erbB2 proteins in a single cluster on nonactivated SKBR3 cells was about 10(3). Activation of SKBR3 cells with EGF, heregulin as well as a partially agonistic anti-erbB2 monoclonal antibody led to an increase in the mean cluster diameter to 0.6-0.9 microm, irrespective of the ligand. The EGF-induced increase in the erbB2 cluster size was inhibited by the EGFR-specific tyrosine kinase inhibitor PD153035. The average size of erbB2 clusters on the erbB2-transfected line of CHO cells (CB2) was similar to that of activated SKBR3 cells, a finding correlated with the increased base-line tyrosine phosphorylation of erbB2 in cells expressing only erbB2. We conclude that an increase in cluster size may constitute a general phenomenon in the activation of erbB2.
Sujet(s)
Microscopie à force atomique/méthodes , Récepteurs à activité tyrosine kinase/métabolisme , Récepteur ErbB-2/métabolisme , Animaux , Cellules CHO , Cricetinae , Activation enzymatique , Antienzymes/pharmacologie , Récepteurs ErbB/antagonistes et inhibiteurs , Humains , Microscopie confocale , Quinazolines/pharmacologie , Cellules cancéreuses en cultureRÉSUMÉ
The human papillomaviruses (HPV) are regarded as one of the important agents of cervical carcinoma. A multicentre study was organized to determine the prevalence of HPV in the fertile female population in Hungary. Parallel with the clinical sample collection, a questionnaire interview was performed to acquire data on the life style, socioeconomic status, sexual practice, etc. 1200 women were examined colposcopically and cervix samples were collected for cytology and the detection of HPV DNA. 17.4% of the samples were HPV-infected. 3.9% of the patients had acquired low-risk, and 10.1% 10.2% high-risk HPV types; 3.4% of the women were at the same time infected with both low-risk and high-risk HPV types. Simultaneously performance of cytology and the HPV hybrid capture assay contribute to recognise and treat the precancerous status and risk factors.
Sujet(s)
Hybridation d'acides nucléiques , Papillomaviridae/isolement et purification , Infections à papillomavirus/diagnostic , Tumeurs du col de l'utérus/virologie , Adolescent , Adulte , Femelle , Humains , Adulte d'âge moyen , Infections à papillomavirus/virologie , Tumeurs du col de l'utérus/diagnosticRÉSUMÉ
PURPOSE: Our purpose was to measure sperm creatine phosphokinase (CK) activity, which reflects cytoplasmic retention in immature spermatozoa, in normospermic and oligozospermic Hungarian men. METHODS: A study of 109 randomly selected men in a university-based andrology laboratory was done. RESULTS: CK activity differed between normospermic and oligozospermic men (0.21 +/- 0.02 vs. 1.19 +/- 0.15 CK IU/10(8) sperm; n = 56 and n = 53; mean +/- standard error of the mean, respectively). There was an inverse correlation between sperm concentration and CK activity (r = -0.70; n = 109). However, 28% of men in the range with less than 10 million sperm/ml had normal sperm CK activity (below the mean + 2 standard deviations of the group with greater than 30 x 10(6) sperm/ml), whereas 36% of men in the group with 20-30 million sperm/ml and 5% in the group with greater than 30 million sperm/ml had elevated CK activities, indicating that the incidence of mature and immature spermatozoa in specimens is independent from the sperm concentrations. CONCLUSIONS: The improved facility of sperm CK activity measurements, compared with sperm concentrations, in the assessment of sperm maturity was confirmed in a Hungarian population. The CK measurements aid the selection of the most efficient treatment for couples with male-factor or unexplained infertility, particularly when considering the options of intrauterine insemination, varicocelectomy followed by a waiting period, or ovulation workup/induction in wives of men who are oligozospermic but may have fertile sperm.