Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 73
Filter
1.
Nature ; 551(7679): 187-191, 2017 11 09.
Article in English | MEDLINE | ID: mdl-29088701

ABSTRACT

Forest edges influence more than half of the world's forests and contribute to worldwide declines in biodiversity and ecosystem functions. However, predicting these declines is challenging in heterogeneous fragmented landscapes. Here we assembled a global dataset on species responses to fragmentation and developed a statistical approach for quantifying edge impacts in heterogeneous landscapes to quantify edge-determined changes in abundance of 1,673 vertebrate species. We show that the abundances of 85% of species are affected, either positively or negatively, by forest edges. Species that live in the centre of the forest (forest core), that were more likely to be listed as threatened by the International Union for Conservation of Nature (IUCN), reached peak abundances only at sites farther than 200-400 m from sharp high-contrast forest edges. Smaller-bodied amphibians, larger reptiles and medium-sized non-volant mammals experienced a larger reduction in suitable habitat than other forest-core species. Our results highlight the pervasive ability of forest edges to restructure ecological communities on a global scale.


Subject(s)
Biodiversity , Forests , Amphibians/anatomy & histology , Animals , Birds/anatomy & histology , Body Size , Geographic Mapping , Mammals/anatomy & histology , Population Dynamics , Reptiles/anatomy & histology
2.
Allergol Immunopathol (Madr) ; 46(5): 491-498, 2018.
Article in English | MEDLINE | ID: mdl-29342409

ABSTRACT

BACKGROUND: Allergy to cats is a frequent cause of sensitization to indoor allergens and currently there are few alternatives to specific immunotherapy with cat native extracts. The objective is to develop and characterize a new allergoid to increase the tools available for use in clinical practice. METHODS: The allergoid cat dander extract (ACD) was developed from a native cat dander extract (NCD) by modification with glutaraldehyde, and the optimal process control was determined by SDS-PAGE, DOT BLOT and determination of free amine groups. The ACD was characterized in protein profile by SDS-PAGE, size exclusion chromatography (SEC) and peptide footprint. The allergenic profile of ACD was determined by immunoblot, IgE CAP inhibition and IgG competition ELISA. The major allergen content in NCD was obtained by the ELISA sandwich protocol and was extrapolated to ACD. RESULTS: The control process determined the optimal development of the allergoid. The ACD obtained contains 182.28µg/mg of protein and 11.90µg/mg of Fel d 1. SDS-PAGE and SEC confirmed the presence of high molecular weight proteins in ACD, and the peptide footprint showed the presence of Fel d 1 and Fel d 7. The high degree of polymerization was evidenced with the determination of the reduction of lysine residues in the allergoid, resulting 91.96%. The ACD showed a significant loss of allergenicity respect to NCD, while the IgG-binding capacity was maintained. CONCLUSIONS: The ACD obtained presents a good safety profile, so would be a good alternative for treatment of cat allergy.


Subject(s)
Dander/immunology , Desensitization, Immunologic/methods , Hypersensitivity/immunology , Hypersensitivity/prevention & control , Allergens/chemistry , Allergens/immunology , Animals , Cats , Humans
3.
Sensors (Basel) ; 15(10): 26143-69, 2015 Oct 15.
Article in English | MEDLINE | ID: mdl-26501278

ABSTRACT

Sustainable mobility requires a better management of the available infrastructure resources. To achieve this goal, it is necessary to obtain accurate data about road usage, in particular in urban areas. Although a variety of sensor alternates for urban traffic exist, they usually require extensive investments in the form of construction works for installation, processing means, etc. Wireless Sensor Networks (WSN) are an alternative to acquire urban traffic data, allowing for flexible, easy deployment. Together with the use of the appropriate sensors, like Bluetooth identification, and associate processing, WSN can provide the means to obtain in real time data like the origin-destination matrix, a key tool for trend monitoring which previously required weeks or months to be completed. This paper presents a system based on WSN designed to characterize urban traffic, particularly traffic trend monitoring through the calculation of the origin-destination matrix in real time by using Bluetooth identification. Additional sensors are also available integrated in different types of nodes. Experiments in real conditions have been performed, both for separate sensors (Bluetooth, ultrasound and laser), and for the whole system, showing the feasibility of this approach.

4.
Heliyon ; 10(4): e26363, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38420453

ABSTRACT

A gains optimizer of a fuzzy controller system for an Unmanned Aerial Vehicle (UAV) based on a metaheuristic algorithm is developed in the present investigation. The contribution of the work is the adjustment by the Genetic Algorithm (GA) to tune the gains at the input of a fuzzy controller. First, a typical fuzzy controller was modeled, designed, and implemented in a mathematical model obtained by Newton-Euler methodology. Subsequently, the control gains were optimized using a metaheuristic algorithm. The control objective is that the UAV consumes the least amount of energy. With this basis, the Genetic Algorithm finds the necessary gains to meet the design parameters. The tests were performed using the Matlab-Simulink environment. The results indicate an improvement, reducing the error in tracking trajectories from 30% in some tasks and following trajectories that could not be completed without a tuned controller in other tasks.

5.
Rev Clin Esp ; 212(10): 475-81, 2012 Nov.
Article in Spanish | MEDLINE | ID: mdl-23044423

ABSTRACT

BACKGROUND AND OBJECTIVE: Clinical practice guidelines recommend achieving concentrations of LDL cholesterol less than 100 mg/dl (and in some cases less than 70 mg/dl) in patients with coronary artery disease and/or diabetes mellitus type 2 (DM2). We have examined the compliance with these objectives in patients treated in Spain with these conditions. METHODS: Cross-sectional epidemiological study. Data were obtained during the visit of the study or, in their absence, based on data contained in the medical record by 874 doctors of the 17 autonomous communities in Spain. Demographic information, risk factors, cardiovascular and prescribed treatments were collected. RESULTS: In the final analysis 6.988 (62.7% male) patients were included. 2586 (37%) had coronary disease, 2654 (38%) DM2 and 1748 (25%) both conditions. 65% had metabolic syndrome. Vascular risk factors median number was 4. 57% and 86% showed a concentration of LDL cholesterol >100 and >70 mg/dl respectively. The proportion patients with LDL concentration >100 mg/dl was 4% greater in the DM2 (62.4%) than in coronary patients (57.1%; p0.0001). Concentration of triglycerides >150 mg/dl was higher in patients with DM2 (50.5%) than in coronary patients (43.5%; p0.0001). The proportion of patients with LDL>70 mg/dl was similar in the coronary group and in the DM2 Group (88.4% and 87.0%, respectively). More than half of patients with coronary heart disease (57.5%) or DM2 (55.7%) showed inadequate levels of HDL (<40 mg/dl men; <50 mg/dl women). CONCLUSIONS: More than a half of patients with diabetes mellitus and/or coronary artery disease enrolled in the CODIMET study do not achieve the recommended LDL cholesterol target for high cardiovascular risk patients.


Subject(s)
Cholesterol, LDL/blood , Coronary Disease/blood , Diabetes Mellitus, Type 2/blood , Guideline Adherence/statistics & numerical data , Adult , Aged , Aged, 80 and over , Biomarkers/blood , Combined Modality Therapy , Coronary Disease/complications , Coronary Disease/therapy , Cross-Sectional Studies , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/therapy , Diet Therapy , Female , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Hypolipidemic Agents/therapeutic use , Male , Middle Aged , Practice Guidelines as Topic , Spain , Treatment Outcome
6.
Nano Lett ; 9(11): 3743-8, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19751066

ABSTRACT

Controlled nanoscale self-assembly of magnetic entities in semiconductors opens novel perspectives for the tailoring of magnetic semiconductor films and nanostructures with room temperature functionality. We report that a strongly directional self-assembly in growth direction in Mn-alloyed Ge is due to a stacking of individual Ge(1-x)Mn(x) clusters. The clusters represent the relevant entities for the magnetization of the material. They are formed of a core-shell structure displaying a Mn concentration gradient. While the magnetic moments seem to be carried by the shells of the clusters, their core is magnetically inactive.

7.
Ultramicroscopy ; 109(5): 502-9, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19059722

ABSTRACT

Statistical analysis of atom probe data has improved dramatically in the last decade and it is now possible to determine the size, the number density and the composition of individual clusters or precipitates such as those formed in reactor pressure vessel (RPV) steels during irradiation. However, the characterisation of the onset of clustering or co-segregation is more difficult and has traditionally focused on the use of composition frequency distributions (for detecting clustering) and contingency tables (for detecting co-segregation). In this work, the authors investigate the possibility of directly examining the neighbourhood of each individual solute atom as a means of identifying the onset of solute clustering and/or co-segregation. The methodology involves comparing the mean observed composition around a particular type of solute with that expected from the overall composition of the material. The methodology has been applied to atom probe data obtained from several irradiated RPV steels. The results show that the new approach is more sensitive to fine scale clustering and co-segregation than that achievable using composition frequency distribution and contingency table analyses.

8.
Ultramicroscopy ; 109(5): 535-40, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19028011

ABSTRACT

Aberrations in the ion trajectories near the specimen surface are an important factor in the spatial resolution of the atom probe technique. Near the boundary between two phases with dissimilar evaporation fields, ion trajectory overlaps may occur, leading to a biased measurement of composition in the vicinity of this interface. In the case of very small second-phase precipitates, the region affected by trajectory overlaps may extend to the centre of the precipitate prohibiting a direct measurement of composition. A method of quantifying the aberrant matrix contribution and thus estimating the underlying composition is presented. This method is applied to the Fe-Cu-alloy system, where the precipitation of low-nanometre size Cu-rich precipitates is of considerable technical importance in a number of materials applications. It is shown definitively that there is a non-zero underlying level of Fe within precipitates formed upon thermal ageing, which is augmented and masked by trajectory overlaps. The concentration of Fe in the precipitate phase is shown to be a function of ageing temperature. An estimate of the underlying Fe level is made, which is at lower levels than commonly reported by atom probe investigations.

9.
Ultramicroscopy ; 109(5): 619-24, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19135308

ABSTRACT

The surface composition of an Au-62at%Pd alloy has been studied by means of a catalytic atom probe (CAP) before and after exposures to nitric oxide (NO) at temperatures ranging from 300 to 573K for 20min. Subsequent CAP analysis at 100K revealed a considerable surface enrichment in Pd (to approximately 80at%) after exposure at 573K. This is correlated with the occurrence of NO dissociation, and the formation of strong Pd-O bonds at the surface. Blank experiments in ultra-high vacuum reflect the surface composition of the bulk material, in excellent agreement with electron microprobe analysis. At 573K, no detectable surface segregation occurs in the absence of NO adsorption for the times and temperatures studied. However, classical Metropolis Monte-Carlo simulations performed with a semi-empirical potential on the Au(40)Pd(60) (111), (110) and (100) systems show surface enrichment of gold at equilibrium. This suggests that the temperatures of the clean surface segregation experiments are too low to reach equilibrium within times of the order of hours.

10.
Ultramicroscopy ; 107(9): 720-5, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17391844

ABSTRACT

Specimen heating is shown to occur in the laser-pulsed 3-dimensional atom probe (3DAP), even in the case of femtosecond pulse lengths. This can have an impact on the spatial resolution of 3DAP analysis, due to surface diffusion, and peak temperatures must be kept sufficiently low to avoid these effects. Similarly, mass resolution can be limited in the analysis of low thermal conductivity materials, due to the slower cool-down of the specimen after the pulse. In such cases, the use of lower repetition frequencies and specimens with large shank angles is shown to improve mass resolution and reduce the noise and degradation in quantitative accuracy resulting from increases in base temperature.

11.
Ultramicroscopy ; 107(9): 705-12, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17485173

ABSTRACT

In this paper, we present calculations and experimental results obtained using post deceleration of ions in a scanning atom probe (SAP) geometry to improve the mass resolution. Various electrode geometries, tip to electrode distances in the range 50-170 microm and three different pulse shapes have been evaluated. Experimental mass resolutions of 750 FWHM and 200 FWTM have been achieved reproducibly for the 184W3+ peak without the use of a reflectron lens. 3D finite element electrostatics software has been used to simulate the ion trajectories through the instrument and thus to calculate the variations in velocities for the different electrode configurations. The observed trends are found to agree well with experimental results.

12.
Ultramicroscopy ; 107(9): 808-12, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17449183

ABSTRACT

Hardness measurements confirm that the martensitic microstructure of an alloy steel, AISI/SAE 4340, is significantly more resistant to softening, compared to the martensitic microstructure of a high-purity Fe-0.4% C alloy, at tempering temperatures, 300-400 degrees C, just above the temperatures where cementite replaces transition carbides in the martensitic matrix. Three-dimensional atom probe (3DAP) analyses of the 4340 steel show that Si rejection from the cementite is first detected after low-temperature tempering for times of 1 h. After 10-h tempering at 400 degrees C, Mn and Cr contents are increased, and Ni contents decreased, in cementite according to their carbide- and non-carbide-forming tendencies, respectively. The results are discussed with respect to the diffusivity of the substitutional alloying elements in the 4340 steel, and the effect that such diffusion-controlled redistribution would have on maintaining fine distributions of cementite that resist softening during tempering.

13.
Mol Biol Cell ; 9(11): 3107-18, 1998 Nov.
Article in English | MEDLINE | ID: mdl-9802900

ABSTRACT

We have shown previously that interleukin-4 (IL-4) protects TS1alphabeta cells from apoptosis, but very little is known about the mechanism by which IL-4 exerts this effect. We found that Akt activity, which is dependent on phosphatidylinositol 3 kinase, is reduced in IL-4-deprived TS1alphabeta cells. Overexpression of wild-type Akt or a constitutively active Akt mutant protects cells from IL-4 deprivation-induced apoptosis. Readdition of IL-4 before the commitment point is able to restore Akt activity. We also show expression and c-Jun N-terminal kinase 2 activation after IL-4 deprivation. Overexpression of the constitutively activated Akt mutant in IL-4-deprived cells correlates with inhibition of c-Jun N-terminal kinase 2 activity. Finally, TS1alphabeta survival is independent of Bcl-2, Bcl-x, or Bax.


Subject(s)
Apoptosis , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Interleukin-4/metabolism , Mitogen-Activated Protein Kinases , Protein Serine-Threonine Kinases , Proto-Oncogene Proteins/metabolism , Animals , Cell Line , Enzyme Activation , JNK Mitogen-Activated Protein Kinases , Mice , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt , Up-Regulation
14.
Cell Death Differ ; 6(1): 87-94, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10200552

ABSTRACT

A variety of environmental stresses, as well as inflammatory cytokines, induce activation of c-Jun N-terminal kinases. We describe here that IL-2 deprivation-induced apoptosis in TS1alphabeta cells does not modify c-Jun protein levels and correlates Bcl-2 downregulation and an increase in JNK1, but not JNK2, activity directly related to the induction of apoptosis. Indeed, downregulation of JNK1 expression using antisense oligonucleotides inhibits apoptosis induced by IL-2 withdrawal. Overexpression of Bcl-2 promotes cell survival and blocks JNK1 activation as well as apoptosis caused by IL-2 deprivation. This suggests that inhibition of the JNK1 signaling pathway may be a mechanism through which Bcl-2 promotes cell survival and prevents apoptosis triggered by growth factor withdrawal.


Subject(s)
Apoptosis , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Interleukin-2/deficiency , Mitogen-Activated Protein Kinases , Proto-Oncogene Proteins c-bcl-2/metabolism , T-Lymphocytes/metabolism , Animals , Cell Line , Down-Regulation , Enzyme Activation , Flow Cytometry , Gene Expression Regulation , JNK Mitogen-Activated Protein Kinases , Mice , Mitogen-Activated Protein Kinase 9 , Oligonucleotides, Antisense/pharmacology , Protein Kinases/metabolism , Signal Transduction
15.
Ultramicroscopy ; 102(2): 151-9, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15590138

ABSTRACT

Field ion microscope images have been used to measure the local evaporation field of a Al3Zr particle in 7050 Al alloy. Using the matrix Al evaporation field (19 V/nm) as a reference, the evaporation field of Al3Zr has been estimated to be 36 V/nm, similar to the theoretical value for the field evaporation of Al2+ or Zr3+ ions. A strong local magnification effect from the large difference in evaporation fields between the particle and matrix has been found to cause a severe distortion of the apparent particle morphology in a three-dimensional atom probe reconstruction when using parameters based on the Al matrix. Use of the measured evaporation field for Al3Zr has allowed accurate reconstruction of the morphology of the particle. A simple worst-case analysis predicts that trajectory overlaps increase with increasing cross-section of particle, and the calculated overlaps agree well with experimental estimates of approximately 1.4-2.0 nm for variations in the particle cross-section from 7 to 12 nm. The chemical composition of Al3Zr in a 7050 Al alloy has been measured to be 64.8-67.7 at% Al, 23.6-24.8 at% Zr, 6.9-9.1 at% Zn, 0.4-0.7 at% Cu, 0.5-1.2 at% Mg, with a (Al+Zn)/Zr ratio close to 3. Specimen analysis temperatures of either 25 or 80 K show little effect on the measured chemical compositions of the particle.


Subject(s)
Alloys/analysis , Aluminum/chemistry , Microscopy , Trace Elements/chemistry , Electron Probe Microanalysis , Models, Theoretical
16.
Data Brief ; 5: 626-41, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26958619

ABSTRACT

Atom Probe Tomography (APT) analysis and hardness measurements were used to characterize the early stages of precipitation in an Al-0.51 at%Mg-0.94 at%Si alloy as reported in the accompanying Acta Materialia paper [1]. The changes in microstructure were investigated after single-stage or multi-stage heat treatments including natural ageing at 298 K (NA), pre-ageing at 353 K (PA), and automotive paint-bake ageing conditions at 453 K (PB). This article provides and a detailed report on the experimental conditions and the data analysis methods used for this investigation. Careful design of experimental conditions and analysis methods was carried out to obtain consistent and reliable results. Detailed data on clustering for prolonged NA and PA treatments have been reported.

17.
Rev Esp Anestesiol Reanim ; 62(2): 81-9, 2015 Feb.
Article in English, Spanish | MEDLINE | ID: mdl-25048999

ABSTRACT

OBJECTIVE: Assess the effectiveness of priming the extracorporeal circulation system with albumin-mannitol combined with ultrafiltration during extracorporeal circulation to reduce post-operative bleeding and transfusion requirements in heart surgery, as well as its impact on the fluid balance, coagulation and hematocrit parameters, re-operation for bleeding, ICU, and hospital length of stay. MATERIAL AND METHODS: A total of 134 patients scheduled for heart surgery were randomized to receive Ringer's lactate 1,500mL in the priming reservoir (group C), or mannitol 20% 250mL, albumin 20% 150mL and Ringer's lactate 1,100mL combined with ultrafiltration (group T). Bleeding volume, transfusions, fluid balance, coagulation, and hematology parameters were determined until 48h in the post-operative period. RESULTS: There was a reduction of postoperative bleeding in group T, 1,165±789mL vs 992±662mL (P=.17), and red blood cell concentrate transfusions, 694±843mL vs 413±605mL (P=.03). Intra-operative and post-operative fluid balance was significantly less positive in group T, with an overall balance of 2,292±2,152mL vs 5,388±2,834mL (P<.001). There were higher values of hemoglobin and hematocrit, intraoperative (P<.001), on admission to ICU (P=.001), and at 6h (P=.05) in group T, and lower INR at 6h (P=.01) and 24h (P=.02). Re-operation rate and length of stay in ICU were higher in group C, but not statiscally significant. CONCLUSIONS: The priming of extracorporeal reservoir with mannitol, albumin, and Ringer's lactate, combined with ultrafiltration, significantly improves intra- and post-operative fluid balance, resulting in a reduction in blood transfusions, with no significant decrease in post-operative bleeding, re-operation bleeding rate, and length of stay in the ICU.


Subject(s)
Albumins/pharmacology , Blood Transfusion/statistics & numerical data , Cardiac Surgical Procedures , Extracorporeal Circulation/methods , Isotonic Solutions/pharmacology , Mannitol/pharmacology , Postoperative Hemorrhage/prevention & control , Aged , Aged, 80 and over , Albumins/administration & dosage , Blood Coagulation Tests , Blood Loss, Surgical , Colloids/administration & dosage , Crystalloid Solutions , Female , Hematocrit , Hemoglobins/analysis , Humans , Isotonic Solutions/administration & dosage , Length of Stay/statistics & numerical data , Male , Mannitol/administration & dosage , Middle Aged , Postoperative Hemorrhage/therapy , Ringer's Lactate , Tranexamic Acid/therapeutic use , Ultrafiltration , Water-Electrolyte Balance/drug effects
18.
Antiviral Res ; 64(2): 137-41, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15498610

ABSTRACT

In the present study, the protective effect of 1T1, a lambda-carrageenan extracted from the red seaweed Gigartina skottsbergii was evaluated in a murine model of herpes simplex virus type 2 (HSV-2) genital infection. Six to eight-week-old female BALB/c mice were intravaginally inoculated with a lethal dose of HSV-2 (MS strain) and pre- or post-infection treated with different doses of a 10mg/ml solution of 1T1. A single topical administration of 1T1 shortly before infection of BALB/c mice with HSV-2 protected 9 out of 10 mice from HSV-2-induced lesions and mortality, compared with only 10% survival in control mice. In addition, 1T1 produced a total blockade in virus shedding in the vaginal secretions. When 1T1 pre-treatment was reinforced with a second dose 2h after infection, total protection was observed even when the prophylactic administration had taken place at 60min before infection. The irreversible virucidal action of 1T1 against herpes virus seems to be responsible of its protective effect against virus replication and mortality following vaginal HSV-2 infection.


Subject(s)
Antiviral Agents/administration & dosage , Carrageenan/administration & dosage , Herpes Genitalis/prevention & control , Vaginal Diseases/prevention & control , Animals , Chlorocebus aethiops , Female , Herpes Genitalis/mortality , Herpes Genitalis/physiopathology , Herpesvirus 2, Human , Mice , Mice, Inbred BALB C , Vagina/virology , Vaginal Diseases/mortality , Vaginal Diseases/physiopathology , Vaginal Diseases/virology , Vero Cells , Virus Shedding
19.
Antiviral Res ; 43(2): 93-102, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10517311

ABSTRACT

The lambda-carrageenan 1T1, the kappa/iota-carrageenan 1C1 and the mu/nu-type 1C3, isolated from the red seaweed Gigartina skottsbergii, proved to be potent and selective inhibitors of herpes simplex virus (HSV) types 1 and 2. The antiviral IC50 values determined by virus yield inhibition assay in different cell lines ranged from 0.4 to 3.3 microg/ml, and no cytotoxic effects, measured by trypan blue exclusion on stationary or proliferating cells, tetrazolium salt method or cell protein synthesis, were observed. Time of addition and attachment studies suggested that the main target for antiviral action of the three carrageenans was virus adsorption, whereas no effect on virus internalization, or early or late protein synthesis was detected. However, the lambda-carrageenan 1T1 was still significantly inhibitory when added any time after adsorption. The pretreatment of virions with the carrageenans showed that 1C1 and 1C3 lacked direct inactivating effect at concentrations near the antiviral IC50 but 1T1 exerted virucidal action. The cyclization of 1T1 to afford the derivative 1T1T1 maintained the antiviral activity but eliminated the virucidal properties. Thus, the structure of 1T1 seems to be responsible for its differential behavior from 1C1 and 1C3, probably allowing a more stable binding to HSV, leading to virion inactivation. In contrast, 1C1 and 1C3 fail to bind with high affinity to virus alone, but are able to interfere with the interaction between HSV particles and the cell.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Carrageenan/chemistry , Carrageenan/pharmacology , Simplexvirus/drug effects , Adsorption , Animals , Antiviral Agents/isolation & purification , Carrageenan/isolation & purification , Carrageenan/toxicity , Cell Line , Cell Survival/drug effects , Chlorocebus aethiops , Herpesvirus 1, Human/drug effects , Herpesvirus 1, Human/physiology , Herpesvirus 2, Human/drug effects , Herpesvirus 2, Human/physiology , Humans , Inhibitory Concentration 50 , Seaweed/chemistry , Simplexvirus/physiology , Vero Cells , Virion/drug effects , Virus Replication/drug effects
20.
J Reprod Immunol ; 14(3): 213-23, 1988 Dec.
Article in English | MEDLINE | ID: mdl-3225814

ABSTRACT

The horseradish peroxidase (HRP), a glycoprotein rich in mannose and N-acetylglucosamine residues has been used as a ligand to detect receptors for N-glycosidic linked oligosaccharides of glycoproteins in the human spermatozoon. Specific binding of HRP occurred to the membrane and the binding sites were visualized with 3,3'-diaminobenzidine-H2O2 (DAB-H2O2) reagent, and by fluorescence when the FITC-peroxidase was used. This specific binding was suppressed by alpha-D-methyl-mannoside and human chorionic gonadotropin, decreased by follicle stimulating and luteinizing hormones and slightly diminished by N-acetylglucosamine. The distribution of the N-linked oligosaccharide specific receptors for glycoproteins in the different zones of the membrane of the spermatozoon was determined by counting the spermatozoa labeled in those zones. The pattern of the distribution is similar to that found for N-linked oligosaccharides containing glycoproteins of the same membrane. The similarity of these distributions together with the general model for cell-to-cell recognition suggest that the sperm-egg interaction mechanism could consist of dual interactions by double binding receptors.


Subject(s)
Glycoproteins/metabolism , Oligosaccharides/metabolism , Platelet Glycoprotein GPIb-IX Complex , Platelet Membrane Glycoproteins , Receptors, Immunologic/metabolism , Spermatozoa/metabolism , Cell Membrane/metabolism , Histocytochemistry , Horseradish Peroxidase/metabolism , Humans , Male
SELECTION OF CITATIONS
SEARCH DETAIL