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2.
Trials ; 22(1): 935, 2021 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-34924004

RESUMEN

BACKGROUND: Trials involving adults who lack capacity to provide consent rely on proxy or surrogate decision-makers, usually a family member, to make decisions about participation. Interventions to enhance proxy decisions about trial participation are now being developed. However, a lack of standardised outcome measures limits evaluation of these interventions. The aim of this study was to establish an agreed standardised core outcome set (COS) for use when evaluating interventions to improve proxy decisions about trial participation. METHODS: We used established methods to develop the COS including a consensus study with key stakeholder groups comprising those who will use the COS in research (researchers and healthcare professionals) and patients or their representatives. Following a scoping review to identify candidate items, we used a modified two-round Delphi survey to achieve consensus on core outcomes, with equivocal items taken to a consensus meeting for discussion. The COS was finalised following an online consensus meeting in October 2020. RESULTS: A total of 28 UK stakeholders (5 researchers, 10 trialists, 3 patient/family representatives, 7 recruiters and 3 advisors/approvers) participated in the online Delphi survey to rank candidate items from the scoping review (n = 36) and additional items proposed by participants (n = 1). Items were broadly grouped into three categories: how family members make decisions, their experiences of making decisions, and the personal aspects that influence the decision. Following the Delphi survey, 27 items were included and ten items exhibited no consensus which required discussion at the consensus meeting. Sixteen participants attended the meeting, including additional patient/family representatives invited to increase representation from this key group (n = 2). We reached consensus for the inclusion of 28 outcome items, including one selected at the consensus meeting. CONCLUSIONS: The study identified outcomes that should be measured as a minimum in all evaluations of interventions to enhance proxy decisions about trials. These relate to the process of decision-making, proxies' experience of decision-making, and factors that influence decision-making such as understanding. Further work with people with impairing conditions and their families is needed to explore their views about the COS and to identify appropriate outcome measures and timing of measurement. TRIAL REGISTRATION: The study is registered on the COMET database ( https://www.comet-initiative.org/Studies/Details/1409 ).


Asunto(s)
Personal de Salud , Evaluación de Resultado en la Atención de Salud , Adulto , Consenso , Humanos , Consentimiento Informado , Investigadores
3.
J Exp Med ; 157(5): 1471-82, 1983 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-6304225

RESUMEN

125I-labeled rat preputial gland beta-glucuronidase was shown by light and electron microscopic radioautography to accumulate within the parasitophorous vacuoles of in vitro derived bone marrow macrophages infected with Leishmania mexicana amazonensis. beta-glucuronidase uptake was mediated by the mannose receptor, since the penetration of the ligand was inhibited by mannan. Uptake was detected as soon as 4 h after incubation of infected cells with the ligand, and increased at 24 and 48 h. The label persisted in the vacuoles for at least 24 h after a 24-h pulse with the ligand, a finding compatible with the relatively long half-life of labeled beta-glucuronidase in normal macrophages. Parasitophorous vacuoles were also labeled in macrophages exposed to the ligand only before infection, indicating that secondary lysosomes containing the ligand fused with the parasitophorous vacuoles. Another mannosylated ligand, mannose-BSA, which, in contrast to beta-glucuronidase, is rapidly degraded in macrophage lysosomes, did not detectably accumulate in the vacuoles. The results support and extend information previously obtained with electron opaque tracers that emphasizes the phagolysosomal nature of Leishmania parasitophorous vacuoles. In addition, the results suggest that appropriate mannosylated molecules may be used as carriers for targeting of leishmanicidal drugs to the parasitophorous vacuoles of infected macrophages.


Asunto(s)
Glucuronidasa/metabolismo , Lectinas Tipo C , Leishmaniasis/enzimología , Macrófagos/parasitología , Lectinas de Unión a Manosa , Receptores de Superficie Celular , Animales , Autorradiografía , Cricetinae , Femenino , Cinética , Leishmaniasis/parasitología , Macrófagos/metabolismo , Macrófagos/ultraestructura , Manosa/metabolismo , Receptor de Manosa , Mesocricetus , Ratones , Ratones Endogámicos , Albúmina Sérica/metabolismo , Vacuolas/enzimología , Vacuolas/parasitología
4.
Cancer Res ; 39(10): 4091-7, 1979 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-476645

RESUMEN

Macromomycin is shown to inhibit the biosynthesis of RNA, DNA, and protein in cultured cells of KB, HBL-100, SW-613, MCF-7, and A1Ab. There was no substantial increase in cell numbers in cultures containing macromomycin (5 microgram/ml), but after 24 to 48 hr the cells were two to three times the diameter of control cells with concomitant increase in cell protein. The ultrastructural changes induced by macromomycin in KB cells demonstrate an increase in nuclear size without similar changes in the size of other cytoplasmic subcellular units. It was of interest to note the general proliferation of cellular organelles and the increased occurrence of annulate lamellae followed, after prolonged treatment, by the appearance of larger numbers of lipid droplets and lysosomes; vacuoles developed to a significant extent after the cells detached from the monolayer. A1Ab cells show ultrastructural changes similar to those of KB cells when treated with macromomycin.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Núcleo Celular/efectos de los fármacos , ADN/biosíntesis , Biosíntesis de Proteínas , ARN/biosíntesis , Recuento de Células , División Celular/efectos de los fármacos , Células Cultivadas , Humanos , Microscopía Electrónica , Organoides/efectos de los fármacos , Péptidos/farmacología
5.
Cancer Res ; 40(2): 225-31, 1980 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7356505

RESUMEN

Cesalin rapidly inhibits the incorporation of uridine and thymidine into KB, MCF-7, HBL-100, and HTC cells but has no measurable effect on AlAb cells. Protein syntheiss is inhibited only after the effect on DNA and RNA is observed. After 12 to 48 hr, the cells in cultures containing cesalin increasingly lose adhesion to the flask surface and float in the medium. Both the inhibition of nucleotide incorporation and the inhibition of the cell growth, used as assays for cytotoxicity, show a varying sensitivity of these cell lines to cesalin, with AlAb cells being the most resistant and KB cells being the most sensitive. The ultrastructural changes induced by cesalin in KB cells demonstrate alteration in the nucleolus, increase in rough endoplasmic reticulum, extensive blebbing of the plasma membrane, and invagination of the nuclear membrane. The blebbing of the plasma membrane decreases after 24 hr with the appearance of a highly disorganized nuclear structure and numerous vacuoles containing insoluble fragments.


Asunto(s)
ADN de Neoplasias/biosíntesis , Neoplasias Experimentales/tratamiento farmacológico , Proteínas de Plantas/farmacología , ARN Neoplásico/biosíntesis , Línea Celular , Membrana Celular/ultraestructura , Retículo Endoplásmico/ultraestructura , Humanos , Microscopía Electrónica , Neoplasias Experimentales/metabolismo , Neoplasias Experimentales/ultraestructura , Membrana Nuclear/ultraestructura
6.
Cancer Res ; 46(8): 4217-20, 1986 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-3524802

RESUMEN

We have devised a method utilizing a monoclonal antibody-toxin conjugate (LICR-LON-Fib75/abrin A-chain) for ridding bone marrow of infiltrating breast cancer cells to rescue patients with autologous bone marrow following high dose therapy. Initially we examined the activity of this conjugate in vitro. Five of seven human breast cancer cell lines were killed following exposure at 10(-8) M for 2 h; this concentration only reduced bone marrow colony formation to 83% (range, 50-100%) of control bone marrow. We then examined the pattern of bone marrow recovery after high dose melphalan (200 mg/m2) in patients with advanced breast cancer who were in remission following combination chemotherapy. To do this we compared the time of recovery of the blood count in three patients who received treated marrow and seven who received untreated marrow. Mean time to recovery of the peripheral white count (greater than 1.5 X 10(9)/liter) was 16.7 days (treated) and 18.3 days (untreated), respectively. Mean time to recovery of peripheral platelet count (greater than 50 X 10(9)/liter) was 23.7 days (treated) and 18.9 days (untreated), respectively. Patients continued in remission for 1-greater than 14 mo after high dose melphalan, and remission duration was similar in patients who received treated (6.2 mo) and untreated (7.3 mo) bone marrow. These findings indicate that treatment of bone marrow with LICR-LON-Fib75/abrin A-chain conjugate does not significantly impair bone marrow recovery, and it is, therefore, possible to rescue breast cancer patients with bone marrow that has been cleansed of infiltrating cancer cells. This may have an application in patients with poor-risk primary breast cancer who have micrometastases and who may benefit from intensive therapy, but it has minimal application in patients with more advanced disease.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Trasplante de Médula Ósea , Neoplasias de la Mama/terapia , Abrina/administración & dosificación , Abrina/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Médula Ósea/efectos de los fármacos , Médula Ósea/patología , Línea Celular , Femenino , Humanos , Melfalán/uso terapéutico , Metástasis de la Neoplasia , Ensayo de Tumor de Célula Madre
7.
Biochim Biophys Acta ; 535(2): 356-69, 1978 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-678557

RESUMEN

The interaction of ovalbumin and its asparaginyl-carbohydrate fractions with concanavalin A was studied. Relative affinities were obtained by competitive binding studies using p-nitrophenyl alpha-D-mannopyranoside. Ovalbumin was separated into two fractions, I and II, by chromatography on concanavalin A-Sepharose. Ovalbumin and its fractions I and II interacted with concanavalin A in solution with binding affinities at 10 degrees C of 2 . 10(5) M-1, 3 . 10(4) M-1 and 2 . 10(6) M-1, respectively. The seven asparaginyl-carbohydrate fractions, obtained by fractionation on Dowex 50W-X2 (H+) and Durrum DA-4 (borate)columns, bound to concanavalin A with approximately the same affinity as native ovalbumin, suggesting that the sugar residues for binding in the isolated carbohydrates are exposed in the native protein. The binding of ovalbumin to concanavalin A was minimal after treatment with alpha-D-mannosidase in spite of the fact that only one half of the available mannose residues were hydrolyzed when compared to those removed by similar treatment of the asparaginyl-carbohydrate before fractionation. It is concluded that those alpha-D-mannosyl residues in ovalbumin that are required for binding to concanavalin A are accessible to alpha-D-mannosidase while the residual mannosyl groups are "buried" from interaction with concanavalin A and the enzyme.


Asunto(s)
Concanavalina A/metabolismo , Ovalbúmina/metabolismo , Asparagina , Unión Competitiva , Carbohidratos , Glicoproteínas , Manósidos/farmacología , Nitrobencenos/farmacología , Unión Proteica/efectos de los fármacos
8.
Biochim Biophys Acta ; 601(1): 101-12, 1980 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-7407156

RESUMEN

125-I-labelled cesalin binds to KB cells and plasma membranes in a specific and saturable manner. At 0 degrees C the cesalin specifically bound to cells is completely displaceable by excess unlabelled cesalin, but at 37 degrees C only 50% can be removed after incubation for 2 h. The extent of binding to plasma membranes has the following characteristics: it is increased following treatment of membranes with cholate; treatment with trypsin has no effect on binding and neither is the bound 125-I-labelled cesalin removed following digestion with trypsin; binding is not inhibited by several carbohydrates but is decreased to about one half by concanavalin A. In addition it is found that some degradation of cesalin occurs with KB cells, the specific binding to which is not enhanced by chloroquine, a lysosomotropic agent. No loss of binding in cells is seen after 4 h exposure to cesalin, suggesting no reduction in the receptors by internalization. The data are consistent with a mechanism in which 125I-labelled cesalin is rapidly bound at 37 degrees C to a receptor on cell membranes through which the biological activity is effected. Slowly, some change in the bound cesalin occurs that prevents its complete displacement from the cells.


Asunto(s)
Membrana Celular/metabolismo , Proteínas de Plantas/metabolismo , Carcinoma , Línea Celular , Membrana Celular/efectos de los fármacos , Humanos , Cinética , Neoplasias de la Boca , Unión Proteica , Tripsina/farmacología
9.
Trends Pharmacol Sci ; 10(11): 458-62, 1989 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2692258

RESUMEN

Receptor-mediated endocytosis is the process whereby binding of a ligand to a cell-surface receptor is followed by internalization of the receptor-ligand complex. After reaching an acidic intracellular endosomal compartment, receptors and ligands are sorted along different pathways for delivery to lysosomes, transport across the cell, or return to the cell surface. Since the first description of receptor-mediated endocytosis in 1974, more than 50 ligands have been found to use receptors to gain access to the interior of the cell, and more than 15 receptors have been purified and sequenced. However, as Virginia Shepherd describes, there are still many unanswered questions concerning sorting signals involved in receptor-ligand routing and the proposed functions of receptor-mediated endocytosis.


Asunto(s)
Endocitosis , Receptores de Droga/fisiología , Animales , Humanos
10.
Cell Mol Biol (Noisy-le-grand) ; 51(7): 607-19, 2005 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-16359611

RESUMEN

J.C. Bose (1858-1937) was one of the world's first biophysicists. He was the first person to use a semi conducting crystal to detect radio waves, and the ingenious inventor of a portable apparatus for generating and detecting microwaves (approximately 1 cm to 5 mm radio waves, frequency 12-60 GHz), as well as inventing many instruments now routinely used in microwave technology. Bose extended his specialist knowledge of the physics of electromagnetic radiation into insightful experiments on the life-processes of plants. He became a controversial figure in the west. He invented unique, delicate instruments for simultaneously measuring bioelectric potentials and for quantifying very small movements in plants. He worked with touch-sensitive plants, including Mimosa pudica, with plants that perform spontaneous movements, including the Indian telegraph plant Desmodium, and with plants and trees that did not make obvious rapid movements. Bose concluded that plants and animals have essentially the same fundamental physiological mechanisms. All plants co-ordinate their movements and responses to the environment through electrical signalling. All plants are sensitive explorers of their world, responding to it through a fundamental, pulsatile, motif involving coupled oscillations in electric potential, turgor pressure, contractility, and growth. His overall conclusion that plants have an electromechanical pulse, a nervous system, a form of intelligence, and are capable of remembering and learning, was not well received in its time. A hundred years later, concepts of plant intelligence, learning, and long-distance electrical signalling in plants have entered the mainstream literature.


Asunto(s)
Fenómenos Fisiológicos de las Plantas , Semiconductores , Fenómenos Biomecánicos , Estimulación Eléctrica , Fenómenos Electromagnéticos/historia , Historia del Siglo XIX , Historia del Siglo XX , India , Fenómenos Fisiológicos del Sistema Nervioso , Desarrollo de la Planta , Plantas/anatomía & histología , Semiconductores/historia , Transducción de Señal
11.
J Leukoc Biol ; 64(3): 345-50, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9738661

RESUMEN

The mannose receptor is a single polypeptide transmembrane glycoprotein expressed on the surface of macrophages that binds and internalizes soluble and particulate ligands. Physiological ligands for this receptor are pathogens, such as mycobacteria, and extracellular acid hydrolases and peroxidases. Expression of the mannose receptor is tightly linked to the functional state of the macrophage: the receptor appears during differentiation, is increased by macrophage deactivating agents, and is reduced in the presence of macrophage activating agents. Studies of the mechanisms underlying these regulatory processes have been hampered by the lack of a stable cell line that expresses a functional and appropriately regulated mannose receptor. In this study we describe expression and modulation of the mannose receptor by the rat alveolar cell line NR8383. Similar amounts of the mannose receptor ligand horseradish peroxidase were internalized by both NR8383 cells and alveolar macrophages. In addition, NR8383 cells expressed immunoreactive mannose receptor protein and mannose receptor mRNA as detected by Northern analysis. Regulation studies showed that mannose receptor expression was regulated at the levels of activity, protein, and mRNA in NR8383 cells similarly to regulation in primary rat macrophages. In addition, NR8383 cells could be successfully transfected with a luciferase reporter gene, providing the transfectable, mannose receptor-positive macrophage cell line. These results support the hypothesis that NR8383 cells potentially represent the best current macrophage cell line for studying various aspects of macrophage function, and are particularly critical in studies of regulation of the mannose receptor, a key receptor in host defense and immune regulation.


Asunto(s)
Lectinas Tipo C , Macrófagos Alveolares/ultraestructura , Lectinas de Unión a Manosa , Receptores de Superficie Celular/fisiología , Animales , Línea Celular , Dexametasona/farmacología , Fibroblastos/metabolismo , Fibroblastos/ultraestructura , Expresión Génica , Genes Reporteros , Glucocorticoides/farmacología , Interferón gamma/farmacología , Macrófagos Alveolares/efectos de los fármacos , Macrófagos Alveolares/metabolismo , Receptor de Manosa , Ratones , ARN Mensajero/metabolismo , Ratas , Receptores de Superficie Celular/biosíntesis , Receptores de Superficie Celular/efectos de los fármacos , Transfección
12.
Immunol Res ; 23(2-3): 111-20, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11444377

RESUMEN

Resident alveolar macrophages play a key role in the initial defense against inhaled pathogens. Surface molecules bind opsonized as well as nonopsonized microbes and mediate their internalization by the macrophage. The recent discovery that specific C-type lectins can bind to the surface of a wide range of pathogens has led to the hypothesis that these lectins are involved in the initial phases of microbe recognition by the macrophage. Studies in our laboratory focus on the role of the lung-specific lectin surfactant associated protein A (SP-A) in host defense against pulmonary pathogens. SP-A contains a carbohdyrate recognition domain that appears to bind specifically to exposed carbohydrate residues on the surface of microorganisms. This lectin-microorganism interaction leads to entry of specific pathogens into macrophages and activation of intracellular pathways, resulting in the production of antimicrobial mediators such as nitric oxide. Many studies, including those involving SP-A-deficient mice, underscore the importance of this protein in pulmonary innate immunity. However, the intramacrophage mechanisms underlying the effects of SP-A are still unclear. This article describes our current knowledge of SP-A and its interactions with immune cells and pathogens with a focus on recent findings from our laboratory regarding SP-A interactions with mycobacteria.


Asunto(s)
Pulmón/microbiología , Macrófagos Alveolares/fisiología , Proteolípidos/fisiología , Surfactantes Pulmonares/fisiología , Animales , Proteínas de la Membrana Bacteriana Externa/metabolismo , Fenómenos Fisiológicos Bacterianos , Quimiotaxis , Humanos , Inmunidad Innata , Mediadores de Inflamación/metabolismo , Lectinas/química , Lectinas/fisiología , Macrófagos Alveolares/metabolismo , Glicoproteínas de Membrana/metabolismo , Ratones , Mycobacterium/fisiología , Proteínas Opsoninas/fisiología , Fagocitosis , Proteolípidos/química , Proteína A Asociada a Surfactante Pulmonar , Proteínas Asociadas a Surfactante Pulmonar , Surfactantes Pulmonares/química , Receptores de Superficie Celular/metabolismo , Transducción de Señal
13.
Invest Ophthalmol Vis Sci ; 32(6): 1779-84, 1991 May.
Artículo en Inglés | MEDLINE | ID: mdl-2032800

RESUMEN

Recent work demonstrated that a mannose receptor is involved in the phagocytosis of rod outer segments by the rat retinal pigment epithelium (RPE). In this study the binding of soluble mannose-containing ligands by human RPE explants is described. In addition, the authors report the isolation of a mannose receptor from human RPE and describe its relationship to the macrophage mannose receptor. Epithelial explants bound the soluble ligand 125I-mannose bovine serum albumin (BSA) by a mannose-specific process. The protein involved in mannose recognition was extracted from human tissue and purified using ligand-affinity chromatography. The protein that bound to the affinity column had a molecular weight of 175 kD by sodium dodecyl sulfate gel electrophoresis and migrated with the same mobility as the human macrophage mannose receptor. Antibodies directed against the macrophage receptor crossreacted with the mannose receptor from human RPE by immunoblot analysis. Binding specificity studies demonstrated that mannose and mannan inhibited ligand binding to the purified receptor by 65% and 90%, respectively; galactose had no effect. Using immunogold labeling of human RPE cells in explant culture, antimacrophage mannose receptor was localized at the apical plasma membrane. These results suggest that human RPE expresses a mannose receptor on its apical surface (as does the rat RPE) and that this receptor is similar to the human macrophage mannose receptor.


Asunto(s)
Lectinas Tipo C , Lectinas de Unión a Manosa , Manosa/metabolismo , Epitelio Pigmentado Ocular/metabolismo , Receptores de Superficie Celular , Receptores Inmunológicos/aislamiento & purificación , Cromatografía de Afinidad , Reacciones Cruzadas , Electroforesis en Gel de Poliacrilamida , Humanos , Immunoblotting , Ligandos , Macrófagos/metabolismo , Mananos , Receptor de Manosa , Peso Molecular , Receptores Inmunológicos/metabolismo
14.
Invest Ophthalmol Vis Sci ; 29(5): 742-8, 1988 May.
Artículo en Inglés | MEDLINE | ID: mdl-3366565

RESUMEN

We report here the presence of a mannose-specific receptor on apical membranes of rat retinal pigment epithelial (RPE) cells. For pinocytic studies, 125I-Mannose-BSA (125I-Man-BSA) was incubated with RPE explants from normal (Long Evans) and dystrophic (pigmented RCS) rat retinas. Normal RPE bound 36.1 ng of ligand and, in the presence of mannan competitor, the amount bound was 18.3 ng. In a similar assay, total ligand uptake by dystrophic RPE was 25.9 ng with 9.8 ng specific for mannose recognition. Comparing the amounts of ligand bound, dystrophic RPE recognized 55% of the amount recognized by normal RPE. The presence of the mannose receptor was localized on both normal and dystrophic RPE apical plasma membranes by autoradiographic techniques using 125I-Man-BSA. Normal RPE showed a greater number of silver grains present at the apical cell membrane as compared to dystrophic RPE. Silver grains were significantly reduced when incubation with the ligand was carried out in the presence of a mannan competitor. Further, in phagocytic studies, latex beads coated with mannan were used as phagocytic particles. Normal RPE phagocytized 4.52 mannan-beads per cell profile by a mannose-specific mechanism, whereas dystrophic RPE did not recognize mannan-beads. Our data suggest that RPE cells express surface receptors which recognize both soluble and particulate mannose ligands. The pinocytic and autoradiographic studies suggest that normal RPE binds more soluble ligand than does dystrophic RPE. If the mannose receptors mediate both pinocytosis and phagocytosis, a possible reduction in number of soluble mannose binding sites on the dystrophic RPE may be related to the diminished phagocytic recognition of particulate ligand by the dystrophic RPE.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Lectinas Tipo C , Lectinas de Unión a Manosa , Fagocitosis , Epitelio Pigmentado Ocular/fisiología , Pinocitosis , Receptores de Superficie Celular , Receptores Inmunológicos/fisiología , Animales , Autorradiografía , Radioisótopos de Yodo , Manosa/metabolismo , Receptor de Manosa , Epitelio Pigmentado Ocular/metabolismo , Epitelio Pigmentado Ocular/ultraestructura , Ratas , Receptores Inmunológicos/metabolismo , Degeneración Retiniana/metabolismo , Degeneración Retiniana/patología , Degeneración Retiniana/fisiopatología
15.
Invest Ophthalmol Vis Sci ; 29(2): 291-7, 1988 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-2962963

RESUMEN

The retinal pigment epithelium (RPE) phagocytizes the tips of photoreceptor outer segments (OS) during normal eye function. It is not known what ligand on OS is recognized by the RPE for removal from the interphotoreceptor matrix. It is possible that a sugar residue on a cell surface glycoconjugate of either the OS or RPE mediates the phagocytic interaction. Pinocytic experiments with a soluble mannose 6-phosphate ligand (125I-labelled mannosidase) showed that similar quantities of ligand were bound by RPE explants from Long Evans rat retinas and from Royal College of Surgeons (RCS/p+) rat retinas known to be defective in the phagocytosis of OS. The addition of mannose 6-phosphate reduced the total counts of bound alpha-mannosidase by 23% in both normal and dystrophic RPE explants. Mannose 6-phosphate receptors were visualized on normal and dystrophic RPE plasma membranes by immunocytochemical techniques. Further, phagocytosis was studied using phosphomannan-coated beads as phagocytic particles. Dystrophic RPE phagocytized phosphomannan-coated beads by a mannose 6-phosphate specific mechanism as shown by a significant reduction in the number of these coated beads taken up in the presence of the competing sugar. In contrast, normal RPE showed no uptake of phosphomannan-coated beads. Our findings indicate that a mannose 6-phosphate receptor is on the apical plasma membrane of rat RPE. This receptor may not be involved in normal OS phagocytic recognition, but may function in the trafficking of lysosomal enzymes by RPE cells.


Asunto(s)
Proteínas Portadoras/metabolismo , Membrana Celular/metabolismo , Epitelio Pigmentado Ocular/metabolismo , Animales , Inmunohistoquímica , Microscopía Electrónica , Microesferas , Fagocitosis , Epitelio Pigmentado Ocular/citología , Epitelio Pigmentado Ocular/ultraestructura , Pinocitosis , Ratas , Ratas Endogámicas , Receptor IGF Tipo 2
16.
Invest Ophthalmol Vis Sci ; 32(5): 1464-70, 1991 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1901835

RESUMEN

A 175-kD mannose-specific receptor has been described in macrophages which appears to mediate pinocytosis and phagocytosis. A mannose-specific receptor has also been found on retinal pigment epithelial cells (RPE). Its role was examined in the phagocytosis of photoreceptor outer segments (ROS) by the RPE. All testing was done on cultured RPE cells challenged with fluorescein isothiocyanate (FITC)-labeled ROS for 4 hr at 37 degrees C. Total (internalized and bound) and phagocytized (internalized) ROS were quantified, and the effects of several experimental conditions on ROS phagocytosis were examined. Incubation of RPE cells in the presence of rabbit anti-serum (1:100) raised against the rat alveolar macrophage mannose receptor (anti-Mr) showed a 80% reduction in ROS phagocytosis compared with RPE in the presence of ROS alone. Anti-Mr preabsorbed with purified human mannose receptor protein (4 micrograms) showed no reduction in ROS phagocytosis. Incubation of RPE with preimmune serum showed no reduction in ROS phagocytosis. When FITC-labeled ROS (1.8 X 10(7)) were preincubated with purified mannose receptor, there was a 93% reduction in phagocytosis. Immunoblots of solubilized rat RPE microvillus membranes stained with the anti-Mr showed a single stained band at the 175-kD region, and immunolocalization studies showed specific labeling along RPE microvilli. These results suggest that a mannose-specific receptor is involved in retinal phagocytosis.


Asunto(s)
Lectinas Tipo C , Lectinas de Unión a Manosa , Fagocitosis , Receptores de Superficie Celular , Receptores Inmunológicos/fisiología , Segmento Externo de la Célula en Bastón/inmunología , Animales , Células Cultivadas , Fluoresceína-5-Isotiocianato , Fluoresceínas , Immunoblotting , Receptor de Manosa , Epitelio Pigmentado Ocular/inmunología , Ratas , Ratas Endogámicas , Tiocianatos
17.
Bone Marrow Transplant ; 16(5): 707-9, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8547869

RESUMEN

A prospective study was undertaken to compare the total nucleated cell (TNC), mononuclear cell (MNC), CD34+ cell, and CFU-GM yields of two different cell separators. A Haemonetics MCS-3P and a Cobe Spectra machine were used to leukapherese 10 patients with malignant diseases on 4 consecutive days after mobilization with G-CSF. All patients were harvested twice on each machine for a fixed period of time. The blood volume processed (10.47 vs 3.79 l, P < 0.001), MNC yield (2.66 vs 0.90 x 10(8)/kg; P < 0.001), MNC yield rate (1.66 vs 0.55 x 10(6)/kg/min; P < 0.001), MNC purity (81 vs 42%; P < 0.001), CFU-GM yield (18.1 vs 5.5 x 10(4)/kg; P = 0.001), and CFU-GM yield rate (11.27 vs 3.42 x 10(2)/kg/min; P = 0.001) were significantly higher with the Spectra. The CD34+ cell yields and yield rates were comparable. Although CFU-GM and MNC yields per unit blood volume processed were comparable for both machines, there was a trend for higher CD34+ yields per unit volume processed with MCS-3P. We conclude that Spectra is faster than MCS-3P with more blood processed per unit time resulting in higher cell yields, but yields per unit volume processed are comparable for both machines. The choice of machine for a given patient depends upon convenience, venous access and the time available.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Leucaféresis/instrumentación , Adulto , Antígenos CD34/análisis , Humanos , Persona de Mediana Edad , Estudios Prospectivos
19.
Bone Marrow Transplant ; 20(10): 843-6, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9404924

RESUMEN

Eighteen patients with poor risk Ewing's sarcoma (including 11 patients with metastatic disease at presentation) received consolidation therapy of busulphan and melphalan with autologous stem cell rescue. There were nine females. The median age at diagnosis was 14.2 years (range 2.75-30 years). There was one early death due to cytomegalovirus pneumonitis. One patient developed a single generalised convulsion during busulphan therapy. Severe renal toxicity was not encountered. One patient developed veno-occlusive disease of the liver (VOD) which eventually resolved. With a median follow up of 2 years, 13 patients survive including six with initial metastatic disease. We conclude that high-dose busulphan/melphalan is well-tolerated and should be evaluated for efficacy in a larger series of patients with high risk Ewing's sarcoma.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Óseas/terapia , Trasplante de Células Madre Hematopoyéticas , Sarcoma de Ewing/terapia , Adolescente , Adulto , Anticonvulsivantes/uso terapéutico , Neoplasias Óseas/tratamiento farmacológico , Neoplasias Óseas/patología , Busulfano/administración & dosificación , Busulfano/efectos adversos , Niño , Preescolar , Clonazepam/uso terapéutico , Terapia Combinada , Contraindicaciones , Supervivencia sin Enfermedad , Femenino , Enfermedad Veno-Oclusiva Hepática/etiología , Humanos , Masculino , Melfalán/administración & dosificación , Metástasis de la Neoplasia , Fenitoína , Inducción de Remisión , Sarcoma de Ewing/tratamiento farmacológico , Sarcoma de Ewing/patología , Convulsiones/inducido químicamente , Convulsiones/prevención & control , Análisis de Supervivencia , Acondicionamiento Pretrasplante/efectos adversos , Resultado del Tratamiento
20.
Bone Marrow Transplant ; 20(6): 435-43, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9313875

RESUMEN

A single centre series of 195 consecutive newly diagnosed untreated myeloma patients under 70 years, seen between September 1986 and March 1994, were analysed to assess the impact of current intensive treatment methods upon remission rate, response rate and subsequent outcome. They were predominantly an unselected population based group of patients (other than by age) that could be used by purchasers of health care as a model for outcome assessment. All patients were scheduled to receive a care plan which included a sequential package of treatment consisting initially of courses of infusional chemotherapy using vincristine, adriamycin and methyl prednisolone (VAMP) and 90 of these also received cyclophosphamide (C-VAMP). Thirty-eight patients received verapamil in addition to C-VAMP(V-C-VAMP). After VAMP all patients were planned to receive high-dose treatment with melphalan and an autograft (marrow or blood) and 112 received this treatment; a further 29 patients received modified high-dose treatment with melphalan alone (23) or busulfan (6) and 54 (28%) did not proceed to high-dose treatment because of refusal, resistant disease, poor performance or treatment-related death. The patients who received melphalan or busulfan alone instead of high-dose melphalan/autografts did so because of increasing age (P = 0.001) and a raised creatinine (P = 0.05). The complete remission rate was 53% for the whole group and 74% for those receiving high-dose melphalan and an autograft. From July 1988, the sequential therapy package included continuous three times weekly interferon (IFN) after high-dose treatment as maintenance therapy, initially as part of a controlled randomised trial and then for all suitable patients. Fifty-seven patients received IFN. The median overall survival (OS) and progression-free survival (PFS) from first treatment for the whole group of 195 patients is 4.5 years and 25 months, respectively. The 112 patients receiving the melphalan autografts fared significantly better than the rest of the patients with OS and PFS (from high-dose treatment) of 6.6 years and 27 months, respectively (P < 0.005), and the 57 patients also receiving IFN have a OS yet to reach a median at 8 years and a PFS of 44 months, significantly better than non IFN high-dose patients (P < 0.0036). However, although we showed benefit for selected patients in studies and trials (particularly with IFN) during the 8-year period of the series, this did not translate into overall PFS benefit in our study for unselected cohorts of patients for 1986-1988 (64 patients) 1989-1992 (100 patients) and 1992-1994 (34 patients) in spite of progressive increases in the proportion of patients receiving IFN (respectively 6, 35 and 58%). This is likely to be due to the dilution of benefit to specific patients by the overall number of patients involved. Outcome data from unselected patients are now expected by purchasers and presented in this way, help qualify the activity impact of advances made from research trials for the treatment of population-based cancer problems.


Asunto(s)
Mieloma Múltiple/terapia , Evaluación de Resultado en la Atención de Salud , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Recuento de Células Sanguíneas/efectos de los fármacos , Trasplante de Médula Ósea/mortalidad , Femenino , Trasplante de Células Madre Hematopoyéticas/mortalidad , Humanos , Interferón-alfa/uso terapéutico , Masculino , Persona de Mediana Edad , Mieloma Múltiple/sangre , Mieloma Múltiple/tratamiento farmacológico , Recurrencia Local de Neoplasia , Vigilancia de la Población , Derivación y Consulta , Inducción de Remisión , Análisis de Supervivencia , Verapamilo/uso terapéutico
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