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1.
ScientificWorldJournal ; 2014: 403683, 2014.
Article in English | MEDLINE | ID: mdl-25386596

ABSTRACT

La Rioja is the region where the top rated wines from Spain come from and also the origin of one of the most prestigious wines in the world. It is worldwide recognized, not only for the quality of the vine, but also for the many factors involved in the process that are controllable by the farmer, such as fertilizers, irrigation, etc. Likewise, there are other key factors, which cannot be controlled that play, however, a crucial role in the quality of the wine, such as temperature, radiation, humidity, and rainfall. This research is focused on two of these factors: temperature and irradiation. The objective of this paper is to be able to recognize these factors, so as to ensure a proper decision criterion when selecting the best location for new vineyard plantations. To achieve this objective, a mesoscale model MM5 is used, and its performance is assessed and compared using different parameters, from the grid resolution to the physical parameterization of the model. Finally, the study evaluates the impact of the different parameterizations and options for the simulation of meteorological variables particularly relevant when choosing new vineyard sites (rainfall frequency, temperature, and sun exposure).


Subject(s)
Agriculture , Models, Theoretical , Vitis/growth & development , Wine , Humidity , Solar System , Temperature
2.
Int J Surg ; 12(6): 572-7, 2014.
Article in English | MEDLINE | ID: mdl-24735893

ABSTRACT

AIMS: A complete clinical response after neoadjuvant chemotherapy (NACT) in breast cancer patients hinders the localization of the residual lesion and the removal of a minimum amount of breast tissue. The aim of the present work is to report our single-centre experience with intraoperative ultrasound-guided (IOUS) excision performed by surgeons in these patients. PATIENTS AND METHODS: From January 2008 to December 2012, IOUS excisions were performed on 58 patients with a previous intralesional ultrasound-detectable metallic marker and non-palpable breast cancer after NACT. The specimen margins were estimated by ultrasonography and macroscopic pathologic examination. Successful lesion removal, specimen weight, and analysis of the results as regards margins were evaluated, and the need for breast-conserving re-excision and mastectomy was considered. RESULTS: After NACT the average ultrasound/mammography and MRI diameters were 11.7 mm (0-30) and 9.1 mm (0-40) respectively. In all cases, the residual lesion or tissue around the marker was removed. The average weight of the specimens was 26.4 g (6-84), being lower in cases of complete response according to ultrasound (p < 0.05). In 4 patients (6.8%), breast-conserving re-excision was carried out, and in 3 patients (5.2%) a secondary mastectomy was performed, two of which had invasive lobular carcinoma. CONCLUSIONS: The emplacement of a readily echodetectable metal marker before NACT makes IOUS excision feasible in an increasing number of complete clinical responses, with the excision of small amounts of breast tissue and a high percentage of conservative breast surgery. This technique requires surgeons to be trained, but has the advantage of a reduced use of other hospital services, better planning of operating theatres, and less discomfort for patients, which means that it is attractive and indeed recommendable.


Subject(s)
Breast Neoplasms/surgery , Mastectomy, Segmental/methods , Neoadjuvant Therapy/methods , Adult , Aged , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Carcinoma, Lobular/diagnostic imaging , Carcinoma, Lobular/drug therapy , Carcinoma, Lobular/pathology , Carcinoma, Lobular/surgery , Chemotherapy, Adjuvant/methods , Feasibility Studies , Female , Humans , Intraoperative Care/methods , Middle Aged , Reoperation/statistics & numerical data , Ultrasonography, Interventional/methods , Ultrasonography, Mammary/methods
3.
Cardiovasc J Afr ; 22(4): 201-2, 2011.
Article in English | MEDLINE | ID: mdl-21881686

ABSTRACT

A 48-year-old male with a symptomatic 2:1 atrio-ventricular block and a dual-chamber pacemaker, implanted one year previously, was admitted due to a syncopal episode. Pacemaker malfunction was identified as the cause of syncope. Subclavian crush syndrome was the cause of the pacemaker malfunction. Its incidence, consequences and management are discussed in this report.


Subject(s)
Atrioventricular Block/therapy , Cardiac Pacing, Artificial/adverse effects , Pacemaker, Artificial/adverse effects , Subclavian Vein/injuries , Vascular System Injuries/etiology , Atrioventricular Block/complications , Equipment Design , Equipment Failure , Humans , Male , Middle Aged , Phlebography , Punctures/adverse effects , Subclavian Vein/diagnostic imaging , Syncope/etiology , Syndrome , Vascular System Injuries/diagnostic imaging
4.
Proc Natl Acad Sci U S A ; 102(16): 5674-8, 2005 Apr 19.
Article in English | MEDLINE | ID: mdl-15824320

ABSTRACT

We present a mandible recovered in 2003 from the Aurora Stratum of the TD6 level of the Gran Dolina site (Sierra de Atapuerca, northern Spain). The specimen, catalogued as ATD6-96, adds to the hominin sample recovered from this site in 1994-1996, and assigned to Homo antecessor. ATD6-96 is the left half of a gracile mandible belonging to a probably female adult individual with premolars and molars in place. This mandible shows a primitive structural pattern shared with all African and Asian Homo species. However, it is small and exhibits a remarkable gracility, a trait shared only with the Early and Middle Pleistocene Chinese hominins. Furthermore, none of the mandibular features considered apomorphic in the European Middle and Early Upper Pleistocene hominin lineage are present in ATD6-96. This evidence reinforces the taxonomic identity of H. antecessor and is consistent with the hypothesis of a close relationship between this species and Homo sapiens.


Subject(s)
Fossils , Hominidae/anatomy & histology , Mandible/anatomy & histology , Paleodontology , Adult , Age Determination by Teeth , Animals , Dentition , Female , Humans , Spain
5.
Biotechnol Appl Biochem ; 34(3): 143-9, 2001 12.
Article in English | MEDLINE | ID: mdl-11730481

ABSTRACT

Chemical alteration of red blood cells (RBCs) can induce increased phagocytosis of modified cells by macrophages. In this study we have used different chemical treatments for the modification of the mouse red-blood-cell membrane surface, namely oxidant compounds, such as ascorbate/Fe(+2) and diamide [azodicarboxylic acid bis(dimethylamide)], or Band 3-cross-linking reagents. We monitored the phagocytosis of oxidized or Band 3-cross-linked mouse red blood cells by peritoneal macrophages. The extent of phagocytosis of RBCs is not affected by oxidation with ascorbate/Fe(3+), but it is increased (up to 10%) by oxidation with 2 mM diamide. Furthermore, phagocytosis is greatly increased (up to 40%) as a result of cross-linking with either of two Band 3 bifunctional reagents [bis(sulphosuccinimidyl) suberate (BS(3)) and 3,3'-dithiobis(sulphosuccinimidyl propionate) (DTSSP)]. To evaluate targeting towards macrophages of such modified RBCs for therapeutical purposes, we have determined the phagocytosis of Band 3 carrier RBCs loaded with carbonic anhydrase. In this case phagocytosis is high enough (25%) to deliver the enzyme into macrophages. We have also assayed the influence of serum components and IgG on the efficiency of phagocytosis and discuss the possible phagocytosis mechanisms. In the case of BS(3)-cross-linked carrier RBCs, phagocytosis is markedly enhanced (from 12% up to 25%) by serum components. This opens a way for therapeutic application of these carrier RBCs, with special relevance in short-term delivery to cells of the mononuclear phagocytic system.


Subject(s)
Cross-Linking Reagents/metabolism , Diamide/metabolism , Erythrocyte Membrane/metabolism , Erythrocytes/physiology , Phagocytosis/physiology , Animals , Anion Exchange Protein 1, Erythrocyte/metabolism , Ascorbic Acid/chemistry , Carbonic Anhydrases/administration & dosage , Drug Carriers/metabolism , Drug Delivery Systems/methods , Erythrocyte Membrane/chemistry , Erythrocytes/metabolism , Macrophages, Peritoneal/physiology , Male , Mice , Oxidation-Reduction , Succinimides/metabolism
6.
Cell Biochem Funct ; 19(2): 89-95, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11335933

ABSTRACT

Different chemical treatments for mouse erythrocyte modification has been used. Oxidation treatments with Ascorbate/Fe(3+), a system able to react with intracellular proteins, produced a displacement of the O(2) binding equilibrium curve to a higher affinity behaviour with loss of the haemoglobin cooperativity for oxygen binding. Incubation of mouse erythrocytes with diamide showed that at low reagent concentration (0.8 mM) no modification on oxygen binding equilibrium curves was observed. At higher reagent concentration (2.0 mM), an increased affinity and a disappearance of the cooperative behaviour can be observed. Additionally, crosslinking reactions on mouse erythrocytes with band 3 crosslinkers seemed to affect oxygen binding properties when used at a crosslinker concentration of 5 mM. Oxyhaemoglobin levels in crosslinked and diamide-treated erythrocytes are similar to those found in control cells. In contrast, ascorbate/Fe(3+) treatments produced an increment in the proportion of methaemoglobin, decreasing the oxyhaemoglobin levels in these oxidized erythrocytes.


Subject(s)
Cross-Linking Reagents/pharmacology , Erythrocytes/metabolism , Ferric Compounds/pharmacology , Oxygen/blood , Animals , Anion Exchange Protein 1, Erythrocyte/chemistry , Ascorbic Acid/pharmacology , Cross-Linking Reagents/chemistry , Diamide/pharmacology , Erythrocytes/drug effects , Hemoglobins/metabolism , Iron/blood , Iron/chemistry , Mice , Mice, Inbred Strains , Oxidation-Reduction , Oxygen/metabolism , Succinimides/pharmacology
7.
Biosci Rep ; 21(6): 857-71, 2001 Dec.
Article in English | MEDLINE | ID: mdl-12166832

ABSTRACT

Chemical oxidation of mouse erythrocytes has been carried out using two different oxidizing systems namely: Diamide and Ascorbate/Fe3+ together with different concentrations of the oxidant. These oxidation treatments produced different extents of modification in membrane proteins as was observed by electrophoretic analyses that showed a possible formation of high molecular weight aggregates. Lipid peroxidation was also observed as the result of these chemical treatments. The action of these two oxidation treatments produced different extents of lipid peroxidation in which the effect Ascorbate/Fe3+ reached higher values than that shown by diamide treatments. To study the resulting in vitro behavior of such oxidized erythrocytes, we have evaluated the recognition of oxidized erythrocytes by peritoneal macrophages. In the conditions used, diamide oxidized erythrocytes were more highly recognized by macrophages than Ascorbate/Fe3+ treated erythrocytes. However, in both cases an influence of serum factors in the recognition process can be inferred. Additionally, we have correlated on one side the action of different oxidation systems on mouse erythrocytes with different in vivo behavior and organ uptake of the oxidized erythrocytes. On the other side, differential targeting of oxidized erythrocytes to a liver or spleen was observed on dependence of the oxidant used.


Subject(s)
Diamide/pharmacology , Erythrocytes/drug effects , Animals , Antioxidants/pharmacology , Ascorbic Acid/pharmacology , Cell Membrane/drug effects , Cell Membrane/metabolism , Cell Survival , Chromium Radioisotopes/metabolism , Erythrocytes/metabolism , Lipid Peroxidation , Macrophages, Peritoneal/metabolism , Mice , Oxidation-Reduction , Sulfhydryl Reagents/pharmacology
8.
Biosci Rep ; 20(3): 157-66, 2000 Jun.
Article in English | MEDLINE | ID: mdl-11095115

ABSTRACT

Membrane protein modification can change cell surface properties which can be correlated with altered macrophage-erythrocyte interactions. Mouse erythrocytes were incubated in phosphate buffer for different times to induce protein modification. Mouse erythrocyte membrane changes were analyzed by infrared analyses and gel electrophoresis. Proteolytic digestion of membrane proteins was observed. After 22 hours preliminary incubation, the number of erythrocytes adhering to a monolayer of macrophages reached a maximum, the majority of which had not been phagocytosed. Most of the erythrocytes incubated for 40 hours underwent phagocytosis after adhesion to the macrophages.


Subject(s)
Cell Membrane/drug effects , Erythrocytes/drug effects , Erythrocytes/metabolism , Macrophages/metabolism , Oxidants/pharmacology , Animals , Buffers , Cell Adhesion/drug effects , Cell Membrane/chemistry , Cell Membrane/metabolism , Chromium/metabolism , Electrophoresis, Polyacrylamide Gel , Endopeptidases/metabolism , Erythrocytes/cytology , Macrophages/cytology , Membrane Proteins/chemistry , Membrane Proteins/metabolism , Mice , Phagocytosis/drug effects , Phosphates/pharmacology , Spectrophotometry, Infrared
9.
Emergencias (St. Vicenç dels Horts) ; 12(1): 14-19, feb. 2000. tab, graf
Article in Es | IBECS | ID: ibc-21960

ABSTRACT

Introducción: Estudios realizados en norteamérica han demostrado la eficacia de algunos índices de gravedad para establecer la probabilidad de supervivencia. Pretendemos determinar su utilidad en pacientes traumatizados graves atendidos por un servicio de emergencias médicas prehospitalario urbano. Métodos: Se estudian los pacientes traumatizados graves atendidos por equipos de soporte vital avanzado durante 1996. Se establecen in situ los valores de "Injurity Severity Score" (ISS), Indice de Shock (IS), "Revised Trauma Score" (RTS) y versión de triage de RTS (T-RTS). Se comparan supervivientes y fallecidos mediante test T de Student y MannWhitney. Se valora la utilidad predictiva de los índices mediante regresión logística. Resultados: Se estudiaron 264 traumatizados graves (el 70 por ciento, consecuencia de un accidente de tráfico), observándose diferencia significativa en supervivientes y fallecidos a 6 y 24 horas para ISS, RTS y T-RTS, pero no para IS. Se ajustó la probabilidad de supervivencia a 6 y 24 horas en función del valor de RTS y T-RTS. Conclusiones: Se comprueba menor utilidad de IS para distinguir al paciente crítico que en estudios americanos, quizás por alterarse más tardíamente. Nuestras probabilidades de supervivencia en las puntuaciones más bajas del RTS y T-RTS son superiores a las publicadas en EE.UU., lo cual puede deberse a la diferente etiología de los traumatismos, nuestros cortos tiempos de respuesta y el tipo de asistencia. RTS y T-RTS son apropiados para establecer probabilidad de supervivencia in situ en traumatizados graves atendidos por un sistema de emergencias médicas prehospitalario urbano. No consideramos adecuado predecir supervivencia basándose en los resultados de sistemas prehospitalarios de atención urgente distintos (AU)


Subject(s)
Humans , Trauma Severity Indices , Wounds and Injuries/mortality , Survival Analysis , Survival Rate/trends , Multiple Trauma/mortality , Transportation of Patients/methods , Accidents, Traffic/mortality
10.
Biosci Rep ; 20(5): 399-410, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11332601

ABSTRACT

Mouse carrier erythrocytes containing 125I-interleukin 3 have been prepared and treated with band 3 crosslinking reagents. The incorporation of interleukin 3 by hypotonic treatment into mouse erythrocytes reached levels of about 15% of the interleukin 3 added to the medium being predominantly present in the cytosolic fraction (73%). Uptake fell to about 7.4% when using the same conditions but omitting hypotonic shock. The interaction of band 3 crosslinked interleukin 3 loaded erythrocytes with macrophages was also studied. A high level of incorporation of interleukin 3 into macrophages was observed either from band 3 crosslinked, interleukin 3-loaded erythrocytes or from interleukin 3 loaded erythrocytes. The observations encourage the view that the system may be able to deliver and target cytokines and other growth factors to macrophages.


Subject(s)
Erythrocytes/metabolism , Interleukin-3/pharmacokinetics , Macrophages, Peritoneal/metabolism , Animals , Anion Exchange Protein 1, Erythrocyte/chemistry , Anion Exchange Protein 1, Erythrocyte/metabolism , Cells, Cultured , Cross-Linking Reagents/chemistry , Drug Delivery Systems , Iodine Radioisotopes , Macrophages, Peritoneal/drug effects , Mice , Mice, Inbred Strains , Succinimides/chemistry
11.
J Hum Evol ; 37(3-4): 623-52, 1999.
Article in English | MEDLINE | ID: mdl-10497002

ABSTRACT

In 1994 and 1995, a 7 m(2)area was excavated at Level 6 of the Gran Dolina site, Atapuerca. A 25 cm deep sub-level, named Aurora Stratum, contained a large number of human fossils, stone tools and faunal remains. The appearance of human remains as part of a butchered faunal assemblage in association with stone tools raises an interesting question relating to human behaviour. The main aim of this paper, therefore, is to evaluate the nature and function of the human occupation at this cave site with a view to understanding the purposes of cannibalism. The zooarchaeological and taphonomic analyses of the macrovertebrate remains focus on species composition, weight and anatomic groups, as well as breakage intensity, type of fragmentation, and surface damage (particularly tool-induced damage) in order to evaluate the faunal source, butchering techniques and economic strategies of the human groups involved. We also studied the distribution and fossil refitting at the site to establish depositional and postdepositional disturbance. Diagenetic breakage due to sediment compression plays an important role in the assemblage, but the most extensive modifications are those produced by human activity for nutritional purposes.


Subject(s)
Archaeology , Fossils , Hominidae , Animals , Bone and Bones/anatomy & histology , Cannibalism , Diet , Ecology , Feeding Behavior , Geography , History, Ancient , Humans , Spain
12.
J Hum Evol ; 37(3-4): 695-700, 1999.
Article in English | MEDLINE | ID: mdl-10497004

ABSTRACT

The study of the faunal and lithic assemblage (including almost a hundred human fossil remains) recovered from the Aurora stratum-TD6 level of the Lower Pleistocene cave site of Gran Dolina (Sierra de Atapuerca, Spain) has allowed us to answer some important questions concerning the debate about the earliest evidence for human occupation of Europe. However, it has also started new discussions about some geographical, ecological, and economic aspects of this earliest occupation. The nature (definitive or ephemeral) of the first occupation, as well as the model for the arrival of the Acheulean (Mode 2) in Europe are also issues for discussion.


Subject(s)
Archaeology , Fossils , Hominidae , Animals , Biological Evolution , Ecology , Geography , History, Ancient , Human Activities/economics , Humans , Spain
13.
Biotechnol Appl Biochem ; 29(1): 59-65, 1999 02.
Article in English | MEDLINE | ID: mdl-10206650

ABSTRACT

Mouse band-3 crosslinked carrier erythrocytes have been prepared. [125I]Carbonic anhydrase (CA) has been encapsulated into mouse erythrocytes. Then, loaded erythrocytes were labelled with 51Cr. Eventually, these doubly labelled cells were crosslinked with band-3 crosslinking reagents. [125I]CA was shown to have cytosolic localization in crosslinked carrier erythrocytes. Estimation of the action of band-3 crosslinkers on mouse carrier-erythrocyte membranes rendered values around 1721% of band-3 monomer reduction. Crosslinked carrier erythrocytes were in vivo targeted to liver, as shown by chromium-labelling localization. Also, encapsulated CA radioactivity was localized in vivo predominantly in liver, which is clearly in contrast with the behaviour shown by free CA injected into animals. These results support this model as a feasible system for the analysis of carrier-erythrocyte survival and targeting as well as the in vivo efficacy of release and targeting of encapsulated compounds.


Subject(s)
Anion Exchange Protein 1, Erythrocyte/chemistry , Carbonic Anhydrases/pharmacokinetics , Cross-Linking Reagents/chemistry , Drug Carriers/chemistry , Erythrocytes/chemistry , Animals , Carbonic Anhydrases/analysis , Carbonic Anhydrases/chemistry , Chromium Radioisotopes , Cross-Linking Reagents/pharmacology , Erythrocyte Membrane/drug effects , Injections, Intraperitoneal , Iodine Radioisotopes , Liver/metabolism , Lung/metabolism , Mice , Mice, Inbred Strains , Myocardium/metabolism , Succinimides/chemistry , Succinimides/pharmacology , Tissue Distribution
14.
Biochimie ; 80(4): 325-32, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9672753

ABSTRACT

Rat band 3 cross-linked carrier erythrocytes have been prepared. Iodinated carbonic anhydrase has been encapsulated into rat erythrocytes. Then, carrier erythrocytes were labeled with 51chromium. Eventually, these doubly labeled rat RBCs were treated with a band 3 cross-linking reagent, namely bis(sulfosuccinimidyl)suberate (BS3). 51Chromium labeling and 125I CA showed to have cytosolic localization in cross-linked carrier erythrocytes. Estimation of the band 3 cross-linking induced by BS3 on rat carrier erythrocytes has been done rendering values around 25% of band 3 monomer reduction. BS3-cross-linked carrier erythrocytes when injected into rats are mainly targeted to liver as shown by chromium labeling localization. Also, encapsulated CA radioactivity carried by cross-linked carrier rat erythrocytes when injected into rats is localized predominantly in liver as shown by in vivo experiments. Accordingly, cross-linked carrier erythrocytes are highly recognized by peritoneal macrophages as detected by in vitro analyses of macrophage recognition. Thus, our data revealed a targeting of carrier rat erythrocytes induced by cross-linking of band 3 protein by BS3. These results support claims in favor of this animal model as a feasible system to analyze cross-linked carrier erythrocytes survival and targeting as well as the in vivo efficacy of targeting of loaded compounds to liver.


Subject(s)
Anion Exchange Protein 1, Erythrocyte/metabolism , Erythrocytes/physiology , Succinimides/pharmacology , Animals , Carbonic Anhydrases/blood , Cell Adhesion , Chromium Radioisotopes , Cross-Linking Reagents , Erythrocyte Membrane/metabolism , Erythrocytes/drug effects , In Vitro Techniques , Iodine Radioisotopes , Liver/physiology , Macrophages, Peritoneal/physiology , Phagocytosis , Rats , Rats, Wistar
15.
Biotechnol Appl Biochem ; 27(2): 133-7, 1998 04.
Article in English | MEDLINE | ID: mdl-9569608

ABSTRACT

Mouse native and hypotonically loaded erythrocytes were treated with two cross-linking reagents: bis(sulphosuccinimidyl)suberate (BS3)- and 3,3'-dithiobis-(sulphosuccinimidyl propionate) (DTSP), excluding clustering agents. Microscopic analyses revealed that band 3 cross-linked native and hypotonically loaded erythrocytes are more strongly recognized by peritoneal macrophages than native and loaded erythrocytes as a result of the cross-linking of band 3 protein in accordance with studies in vivo. Macrophage-recognition analyses of 51Cr-labelled erythrocytes also demonstrated increased recognition of cross-linked and cross-linked loaded erythrocytes. This shows that the only action of these two band 3 cross-linkers on mouse erythrocytes promotes recognition by macrophages without requiring the use of clustering agents. The extent of recognition of BS3 cross-linked and cross-linked loaded erythrocytes by macrophages is dependent on the presence or absence of homologous serum or immunoglobulins. In contrast, the presence of serum factors or IgG in the incubation medium did not seem to influence the recognition of DTSP-modified erythrocytes by macrophages. These results seem to indicate a different mechanism of recognition for the erythrocytes modified with either one or the other band 3 cross-linker. In summary, the unique use of both band 3 cross-linkers procedures can be used to target carrier erythrocytes conveying active compounds to macrophages, with possible therapeutical applications. Different mechanisms of induction of macrophage recognition by these band 3 cross-linkers could reveal differential actions on erythrocytes or the involvement of different factors in the recognition process.


Subject(s)
Anion Exchange Protein 1, Erythrocyte/chemistry , Cross-Linking Reagents/chemistry , Drug Carriers , Erythrocytes/chemistry , Macrophages/physiology , Animals , Chromium Radioisotopes , Erythrocyte Membrane/chemistry , Erythrocyte Membrane/metabolism , Erythrocytes/physiology , Mice , Mice, Inbred Strains , Succinimides/chemistry
16.
Biotechnol Appl Biochem ; 27(2): 139-43, 1998 04.
Article in English | MEDLINE | ID: mdl-9569609

ABSTRACT

Previous investigation has shown that osmotically loaded erythrocytes can act as drug carriers in systemic circulation, whereas chemically modified erythrocytes can be targeted to organs of the mononuclear phagocytic system because of changes introduced in the membrane that are recognized by macrophage cells. In this study we have examined the delivery of 125I-labelled carbonic anhydrase (125I-CA) carried by mouse erythrocytes, either loaded, or loaded and cross-linked with bis(sulphosuccinimidyl)suberate (BS3) and 3,3'-dithiobis-(sulphosuccinimidyl propionate), into homologous peritoneal macrophages maintained in culture. The hypotonically loaded mouse erythrocytes show a slight recognition by macrophages, similar to native erythrocytes. CA loaded into erythrocytes is thus delivered to a limited extent into macrophages. Neither the number of recognized loaded 51Cr-labelled erythrocytes nor the amount of delivered 125I-CA is affected by the presence of serum components or IgG. In contrast, cross-linking these loaded erythrocytes results in a greater phagocytosis by macrophages as assessed by microscopic observations, producing a markedly increased amount of targeted enzyme. The amount of CA delivered into macrophages, after BS3 cross-linker treatment of erythrocytes, is dependent on the presence of serum components in the incubation medium. Thus these cross-linking treatments improve the capacity of loaded mouse erythrocytes to deliver significant amounts of targeted enzyme to macrophage cells, increasing the therapeutic potential of carrier erythrocytes.


Subject(s)
Cross-Linking Reagents/pharmacology , Drug Carriers , Erythrocytes/physiology , Macrophages, Peritoneal/physiology , Animals , Blood Proteins/pharmacology , Capsules , Carbonic Anhydrases/pharmacokinetics , Chromium Radioisotopes , Erythrocytes/chemistry , Erythrocytes/drug effects , Immunoglobulin G/pharmacology , Iodine Radioisotopes , Macrophages, Peritoneal/drug effects , Mice , Mice, Inbred Strains , Phagocytosis , Succinimides/pharmacology
17.
J Biochem ; 123(2): 233-9, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9538197

ABSTRACT

Previous work has shown increased uptake of hypotonically loaded rat RBCs by the spleen and liver "in vivo," suggesting that the cells of MPS are involved in their elimination from the circulation. In order to elucidate the mechanism of such elimination, we have undertaken studies on the interaction of such loaded RBCs, in comparison with native RBCs, with peritoneal macrophages. Erythrophagocytosis assays were performed in well plates to which thioglycollate-induced peritoneal macrophages had adhered. Native or loaded 51Cr-RBCs were added under different opsonization conditions to monolayer adherent macrophages, and then the amount of RBCs that were recognized was determined, with separation into adhesion and phagocytosis fractions. Native RBCs are slightly recognized by peritoneal macrophages, about one RBC per macrophage (Mphi). Osmotic treatment of rat RBCs used for encapsulation (independently of the encapsulated substance, 125I-CA or FITC-dextran) produces some modification in the erythrocyte membrane that induces higher recognition of these cells, about three loaded RBCs per macrophage. Consequently, both fluorescent (FITC-Dx) and radioactive (125I-CA) substances previously encapsulated in RBCs were transferred to M(phi)s. The fluorescence microscopic observations confirmed these results. Moreover, in the case of carrier 51Cr-cells loaded with 125I-CA, the amount of 125I-radioactivity delivered into M(phi)s was relatively higher than that of 51Cr. The highest ratio, 125I-CA (encapsulated substance)/51Cr-RBCs (carrier cells), present in M(phi)s means there was a stronger interaction with macrophages of RBCs that carry a higher amount of encapsulated CA, as a function of the heterogeneity of the loaded rat RBCs population previously reported. Finally, the adhesion and phagocytosis of loaded RBCs seem not to involve complement receptors or Fc receptors on the macrophages.


Subject(s)
Drug Carriers/pharmacology , Erythrocytes/physiology , Macrophages, Peritoneal/physiology , Animals , Carbon Radioisotopes , Cell Adhesion , Dextrans/metabolism , Drug Carriers/metabolism , Erythrocyte Count , Erythrocytes/immunology , Erythrocytes/metabolism , Fluorescein-5-isothiocyanate/analogs & derivatives , Fluorescein-5-isothiocyanate/metabolism , Hypotonic Solutions , Macrophages, Peritoneal/immunology , Macrophages, Peritoneal/metabolism , Microspheres , Phagocytosis , Rats , Rats, Wistar
18.
Biochimie ; 79(1): 53-61, 1997.
Article in English | MEDLINE | ID: mdl-9195046

ABSTRACT

Chemical conditions for cross-linking rat erythrocytes with bis(sulfosuccinimidyl)suberate (BS3) and 3,3' dithiobis(sulfosuccinimidyl propionate) (DTSSP) have been studied. These two cross-linking reagents seem to react with band 3 proteins in rat erythrocyte membrane. Two different conditions have been assayed using different cell/cross-linker concentration ratios. Similar cell volumes were observed in cross-linked rat erythrocytes compared to rat control erythrocytes. Cell yields after cross-linking account for about 65% when a high ratio of cell-to-cross-linker was used. Slightly lower cell yields (about 62%) were obtained when this ratio was reduced. Estimation of band 3 cross-linking by gel electrophoresis revealed a level of cross-linking of around 45% and 50% at the different conditions used. In vivo behavior of these modified rat erythrocytes revealed that they do not circulate, showing a predominant localization in the liver. This effect is evident from the concentration (5 mM BS3 or DTSSP) used. Based on these results, BS3 and DTSSP can be considered as useful tools to cross-link rat erythrocyte band 3 and to target rat erythrocytes to the liver.


Subject(s)
Anion Exchange Protein 1, Erythrocyte/chemistry , Cross-Linking Reagents/chemistry , Erythrocyte Membrane/chemistry , Succinimides/chemistry , Animals , Humans , Linear Models , Organ Specificity , Rats , Rats, Wistar
19.
Biochim Biophys Acta ; 1291(1): 27-34, 1996 Aug 29.
Article in English | MEDLINE | ID: mdl-8781521

ABSTRACT

Chemical conditions of crosslinking mouse erythrocytes with BS3 and DTSSP have been studied. These two crosslinking reagents seem to react with band 3 protein in mouse erythrocytes membrane. Extent of crosslinking is dependent on the concentration of the reagent used. Similar cell volumes were observed in crosslinked erythrocytes with respect to control erythrocytes. In vivo behaviour of these modified erythrocytes revealed prominent targeting of crosslinked erythrocytes to liver. This effect is clearly evident when concentrations of 5 mM BS3 or DTSSP were used and can be dependent of reagent concentration. Consequently, from our results BS3 and DTSSP can be considered as very useful tools to control and modulate targeting of crosslinked erythrocytes.


Subject(s)
Anion Exchange Protein 1, Erythrocyte/chemistry , Cross-Linking Reagents , Erythrocytes/cytology , Succinimides , Animals , Cell Movement , Drug Carriers , Erythrocyte Indices , Erythrocytes/chemistry , Liver/cytology , Mice , Spleen/cytology
20.
J Biochem ; 120(2): 286-91, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8889812

ABSTRACT

Rat RBCs loaded with 125I-CA by hypotonic dialysis and isotonic resealing were evaluated as a carrier system. Loaded RBCs stored at 4 degrees C remained unlysed (90% survival) allowing release of encapsulated 125I-CA for up to 4 days. Thereafter, cellular lysis increased significantly. IP-injected loaded RBCs reached the maximum level (50%) in circulation at 24 h post-injection. Circulating loaded RBCs showed a half-life of 8-10 days, which was advantageous for carrier function. In contrast to IP-injected free CA, which remained in circulation for only a short time, encapsulated CA showed significant levels in circulation up to 10 days post-injection. The profile of organ uptake with time is essentially not altered for loaded with respect to native cells, being higher the removal of loaded cells and mainly localized in spleen. Nevertheless, liver is the organ with highest elimination capacity for both native and loaded cells, showing its maximum at 24 h post-injection. Concomitantly, the concentration of 125I-CA in all organs studied was highest at this time. These data demonstrate that rat loaded RBCs can potentially be used as a carrier system for long-term dissemination of drug into the organism, with specially increased delivery to the spleen. They also support the use of the rat as an experimental model for biochemical and pharmacological studies in these therapeutic systems.


Subject(s)
Drug Carriers , Erythrocytes/metabolism , Animals , Chromium Radioisotopes/blood , Chromium Radioisotopes/pharmacokinetics , Drug Delivery Systems , Erythrocyte Aging , Erythrocytes/cytology , In Vitro Techniques , Iodine Radioisotopes/blood , Iodine Radioisotopes/pharmacokinetics , Liver/cytology , Liver/metabolism , Rats , Rats, Wistar , Time Factors , Tissue Distribution
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