RESUMEN
AIMS: Cytoplasmic accumulation of the nuclear protein transactive response DNA-binding protein 43 (TDP-43) is an early determinant of motor neuron degeneration in most amyotrophic lateral sclerosis (ALS) cases. We previously disclosed this accumulation in circulating lymphomonocytes (CLM) of ALS patients with mutant TARDBP, the TDP-43-coding gene, as well as of a healthy individual carrying the parental TARDBP mutation. Here, we investigate TDP-43 subcellular localization in CLM and in the constituent cells, lymphocytes and monocytes, of patients with various ALS-linked mutant genes. METHODS: TDP-43 subcellular localization was analysed with western immunoblotting and immunocytofluorescence in CLM of healthy controls (n = 10), patients with mutant TARDBP (n = 4, 1 homozygous), valosin-containing protein (VCP; n = 2), fused in sarcoma/translocated in liposarcoma (FUS; n = 2), Cu/Zn superoxide dismutase 1 (SOD1; n = 6), chromosome 9 open reading frame 72 (C9ORF72; n = 4), without mutations (n = 5) and neurologically unaffected subjects with mutant TARDBP (n = 2). RESULTS: TDP-43 cytoplasmic accumulation was found (P < 0.05 vs. controls) in CLM of patients with mutant TARDBP or VCP, but not FUS, in line with TDP-43 subcellular localization described for motor neurons of corresponding groups. Accumulation also characterized CLM of the healthy individuals with mutant TARDBP and of some patients with mutant SOD1 or C9ORF72. In 5 patients, belonging to categories described to carry TDP-43 mislocalization in motor neurons (3 C9ORF72, 1 TARDBP and 1 without mutations), TDP-43 cytoplasmic accumulation was not detected in CLM or in lymphocytes but was in monocytes. CONCLUSIONS: In ALS forms characterized by TDP-43 mislocalization in motor neurons, monocytes display this alteration, even when not manifest in CLM. Monocytes may be used to support diagnosis, as well as to identify subjects at risk, of ALS and to develop/monitor targeted treatments.
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Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Monocitos/metabolismo , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , MutaciónRESUMEN
Here we describe a case of pyometra coexisting with gestation in a 4.5 year-old miniature short-haired Dachshund. The dog exhibited depression, vaginal discharge, polydipsia and dehydration. Ultrasound examination revealed the presence of low to moderate anechoic fluid collection in the left uterine horn. Blood analysis revealed mild neutrophilia with a left shift. Based on these findings a presumptive diagnosis of pyometra was made and the bitch was treated using amoxicillin-clavulanate with dopaminergic agonist (cabergoline). A second ultrasound scan revealed the presence of two gestational vesicles in the right uterine horn that were successfully carried to term. Unusually, while pyometra persisted in the left uterine horn, two viable puppies were delivered by caesarean section from the right uterine horn.
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AIM: Between 15-30% of patients presenting with low back pain have some SI joint involvement. The diagnosis of SI joint involvement in low back pain is quite difficult and depends on a detailed combination of clinical manoeuvres and injection tests. In 5% of patients with SI joint pain, the joint is physically unstable (termed disruption) resulting in ineffective medical and conservative therapeutic options. In this study we present the results of the first 12 cases of SI joint disruption treated using a minimally invasive SI joint arthrodesis system in order to evaluate the safety and the efficacy of this system. METHODS: Medical charts at a single center were reviewed for demographics, perioperative metrics, patient reported outcomes for pain, function and quality of life (NRS, ODI and RDQ respectively), as well as satisfaction with surgery (yes/no) and results of postoperative CT scan. RESULTS: Mean age was 53 years (range 36-71) and all patients were female. Patient reported outcomes at follow up (range 8-18 months) improved clinically as well as statistically as evidenced by a mean improvement in pain on NRS of 4 points, back related function on ODI by 19.4 points, and in quality of life measured using RDQ of 13.6 points (all P=0.01). Local hematoma requiring drainage was apparent in 2 patients. Patient satisfaction was 100%. All 3 month CT scans showed initial fusion. CONCLUSION: The results of this study confirm that MIS SI joint fusion using the iFuse Implant System is safe and effective method of treating patients with SI joint disruption.
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Artrodesis/métodos , Dolor de la Región Lumbar/cirugía , Articulación Sacroiliaca/cirugía , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Satisfacción del Paciente , Proyectos Piloto , Calidad de Vida , Resultado del TratamientoRESUMEN
Interhemispheric connections have been demonstrated between the motor cortex controlling muscle pairs. However, these investigations have tended to concentrate upon hand muscles. We have extended these investigations to proximal muscles that control the scapula upon the trunk and help to move and stabilise the shoulder. Using a paired pulse transcranial magnetic stimulation protocol, the interhemispheric interactions between different shoulder girdle muscle pairs, serratus anterior, upper trapezius and lower trapezius were investigated. Test motor evoked potentials were conditioned using conditioning pulse intensities of 80% and 120% of active motor threshold at three different condition-test intervals, during three different tasks. Interhemispheric inhibition was observed in upper trapezius using a conditioning intensity of 120% and condition-test interval of 8 ms (17 ± 18%, p < 0.007). A trend towards inhibition was observed in lower trapezius and serratus anterior using a conditioning intensity of 120% and a condition-test interval of 8 ms (13 ± 22%; p < 0.07 and 10 ± 19% respectively; p < 0.07). No interhemispheric facilitation was evoked. The study demonstrates that a low level of interhemispheric inhibition rather than interhemispheric facilitation could be evoked between these muscle pairs.
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Lateralidad Funcional/fisiología , Corteza Motora/fisiología , Movimiento/fisiología , Músculo Esquelético/fisiología , Estimulación Magnética Transcraneal/métodos , Adulto , Electromiografía , Potenciales Evocados Motores/fisiología , Femenino , Mano/fisiología , Voluntarios Sanos , Humanos , Masculino , Fuerza Muscular/fisiología , Inhibición Neural/fisiología , Tiempo de Reacción/fisiología , Escápula/fisiología , Tórax/fisiología , Torso/fisiologíaRESUMEN
PURPOSE: To evaluate granulocyte colony-stimulating factor (G-CSF) efficacy in accelerating bone regeneration following opening-wedge high tibial valgus osteotomy for genu varum. METHODS: A phase II trial was conducted for evaluating the preoperative administration of G-CSF given at 10 µg/kg/day for 3 consecutive days with an additional half-dose 4 h before the opening-wedge high tibial valgus osteotomy. Overall, 12 patients (Group A) received G-CSF treatment, and the subsequent 12 patients (Group B) underwent surgery without G-CSF. The osteotomy gap was filled by a bone graft substitute. Bone marrow cell (BMC) mobilization was monitored by CD34+ve cell and clonogenic progenitor cell analysis. All patients underwent a clinical (Lysholm Knee Scale and SF-36) and radiographic evaluation preoperatively, as well as at given intervals postsurgery. RESULTS: All patients completed the treatment program without major side effects; G-CSF was well tolerated. BMC mobilization occurred in all Group A patients, with median peak values of circulating CD34+ve cells of 110/µL (range 29-256). Circulating clonogenic progenitors paralleled CD34+ve cell levels. A significant improvement in Lysholm Knee Scale was recorded at follow-up in Group A compared to Group B. At the radiographic evaluation, there was a significant increase in osseointegration at the bone-graft junction in Group A at 1, 2, 3 and 6 months postsurgery compared to Group B. The computerized tomography scan of the grafted area at 2 months postsurgery showed no significant difference in the quality of the newly formed bone between the two Groups. CONCLUSIONS: Although the limited number of patients does not allow firm conclusions, the study suggests that G-CSF can be safely administered preoperatively in subjects undergoing opening-wedge high tibial valgus osteotomy; in addition, the clinical, radiographic and CT monitoring indicate that G-CSF and/or mobilized BMCs may hasten bone graft substitute osseointegration. LEVEL OF EVIDENCE: I.
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Sustitutos de Huesos , Genu Varum/cirugía , Factor Estimulante de Colonias de Granulocitos/farmacología , Movilización de Célula Madre Hematopoyética/métodos , Oseointegración/efectos de los fármacos , Osteotomía/métodos , Tibia/cirugía , Adulto , Anciano , Esquema de Medicación , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Genu Varum/complicaciones , Genu Varum/diagnóstico por imagen , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Indicadores de Salud , Humanos , Articulación de la Rodilla/diagnóstico por imagen , Articulación de la Rodilla/efectos de los fármacos , Articulación de la Rodilla/fisiología , Articulación de la Rodilla/cirugía , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/diagnóstico por imagen , Osteoartritis de la Rodilla/cirugía , Osteotomía/instrumentación , Cuidados Preoperatorios , Estudios Prospectivos , Tibia/diagnóstico por imagen , Tibia/efectos de los fármacos , Tibia/fisiología , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
A promising approach for musculoskeletal repair and regeneration is mesenchymal-stem-cell- (MSC-)based tissue engineering. The aim of the study was to apply a simple protocol based on mincing the umbilical cord (UC), without removing any blood vessels or using any enzymatic digestion, to rapidly obtain an adequate number of multipotent UC-MSCs. We obtained, at passage 1 (P1), a mean value of 4, 2 × 10(6) cells (SD 0,4) from each UC. At immunophenotypic characterization, cells were positive for CD73, CD90, CD105, CD44, CD29, and HLA-I and negative for CD34 and HLA-class II, with a subpopulation negative for both HLA-I and HLA-II. Newborn origin and multilineage potential toward bone, fat, cartilage, and muscle was demonstrated. Telomere length was similar to that of bone-marrow (BM) MSCs from young donors. The results suggest that simply collecting UC-MSCs at P1 from minced umbilical cord fragments allows to achieve a valuable population of cells suitable for orthopaedic tissue engineering.
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The aim of this study was to assess the efficacy and safety of deslorelin acetate implants on domestic queen puberty postponement. Thirty, 114.4 ± 12.7 days old, 1.5 ± 0.1 kg prepubertal crossbred female cats were included in this study. The animals were kept under a positive photoperiod and randomly assigned to deslorelin acetate 4.7 mg SC implants (n = 15) or to a non-treated control group (n = 15). The queens were followed up daily and weighed weekly until puberty. Vaginal cytology was also carried out three times a week. Puberty was diagnosed by the presence of the typical oestrous behaviour and vaginal cytology findings. At puberty, ovariectomy was performed and the gonads grossly described. Age (281.2 ± 21.6 vs 177.8 ± 10.8; p < 0.01) but not weight (2.6 ± 0.1 vs 2.5 ± 0.1; p > 0.1) at puberty differed between the deslorelin and control groups, respectively. One deslorelin-treated female showed an oestrous response and another showed clinical signs of pyometra after the implants. Deslorelin-treated ovaries appeared small, while control gonads were normal. It was concluded that long-term-release deslorelin, administered at approximately 50% adult body weight, postponed feline puberty without altering growing rate.
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Gatos/crecimiento & desarrollo , Hormona Liberadora de Gonadotropina/agonistas , Maduración Sexual/efectos de los fármacos , Pamoato de Triptorelina/análogos & derivados , Animales , Preparaciones de Acción Retardada , Implantes de Medicamentos , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/farmacología , Femenino , Pamoato de Triptorelina/administración & dosificación , Pamoato de Triptorelina/farmacologíaRESUMEN
The bovine digital vasculature contractility has been implicated in the development of laminitis. To investigate the effect of hypoxia/reoxygenation on the contractility of isolated peripheral bovine digital veins (BDVs), vessel rings were studied under isometric conditions and submitted to 30 min of hypoxia (95%N(2)-5%CO(2)) and reoxygenation (95%O(2)-5%CO(2)) conditions, respectively. The BDVs contracted with a high K(+) depolarizing solution, developed hypoxia-induced relaxation, followed by an increase in tension upon reoxygenation. In contrast, phenylephrine-contracted BDVs displayed a rapid, sustained and reversible hypoxia-induced contraction. Reoxygenation caused a rapid relaxation in phenylephrine-contracted BDVs. The presence of the endothelium did not modify the hypoxia/reoxygenation effects and hypoxia-induced contraction was still observed in a nominal Ca(2+)-free Krebs, however, the last effect was not maintained over time. The hypoxia-induced contraction in an isolated peripheral vein may contribute to the understanding of the physiology and pathophysiology of superficial venous smooth muscle contractility, particularly in the alteration of bovine digital haemodynamics under hypoxia/reoxygenation conditions.
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Miembro Anterior/irrigación sanguínea , Hipoxia/veterinaria , Contracción Muscular/fisiología , Músculo Liso Vascular/fisiopatología , Vasoconstricción/fisiología , Venas/fisiopatología , Animales , Calcio/farmacología , Bovinos , Relación Dosis-Respuesta a Droga , Hipoxia/fisiopatología , Contracción Muscular/efectos de los fármacos , Músculo Liso Vascular/efectos de los fármacos , Fenilefrina/farmacología , Vasoconstricción/efectos de los fármacos , Vasoconstrictores/farmacología , Venas/efectos de los fármacosRESUMEN
Two experiments were conducted to investigate the effects of the GnRH antagonist acyline (330 microg/kg, given sc) on ovarian follicular development and ovulation, as well as on pregnancy maintenance in domestic cats. In the first experiment, seven queens in proestrus (total of 24 proestrus periods), were randomly assigned to treatment with either acyline (ACY; n=17) or a placebo (PLC; n=7). All queens were mated with a fertile tomcat. In the ACY and PLC groups, cessation of estrus occurred (mean+/-SEM) 7.0+/-1.3 and 7.0+/-1.7 d after treatment (P>0.1), ovulation occurred in 2 of 17 and all seven estrus periods (P<0.05), and pregnancy rates were 1 of 16 and 7 of 7 (P<0.05), respectively. In the ACY and PLC groups, intervals from treatment to the onset of the ensuing proestrus were 18.4+/-1.7 and 120+/-17.2 d. In the second experiment, 14 pregnant queens were randomly allocated, according to their mating date, to treatment with acyline in early pregnancy (from 20 to 25 d, n=3), mid pregnancy (from 26 to 45 d; n=4), late pregnancy (> 45 d; n=3), or injection of a placebo in early (n=1), mid (n=2), or late pregnancy (n=1). Ultrasonographic assessments of the uterus were done every second day for 2 wk post treatment, and serum progesterone (P(4)) concentrations were determined before treatment, and at 7 and 14 d after treatment. No pregnancies were prematurely terminated and post-treatment P(4) concentrations did not differ among treatment groups (P>0.1). In conclusion, in the domestic cat, GnRH withdrawal by acyline prevented ovulation when given in early follicular phase (proestrus), but did not significantly affect luteal function during pregnancy.
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Gatos/fisiología , Cuerpo Lúteo/efectos de los fármacos , Hormona Liberadora de Gonadotropina/antagonistas & inhibidores , Oligopéptidos/efectos adversos , Folículo Ovárico/efectos de los fármacos , Ovulación/efectos de los fármacos , Animales , Cuerpo Lúteo/fisiología , Femenino , Edad Gestacional , Masculino , Oligopéptidos/administración & dosificación , Folículo Ovárico/crecimiento & desarrollo , Placebos , Embarazo , Proestro , Progesterona/sangre , Ultrasonografía , Útero/diagnóstico por imagenRESUMEN
Umbilical cord blood (UCB) is a source of hematopoietic progenitor cells and is used as an alternative to the bone marrow or peripheral blood for treatment of several onco-hematological diseases. Because of the limited number of CD34+ hematopoietic stem cells present in UCB units and of the elevated costs of cryopreservation, it is of paramount importance to select the UCB units that are clinically useful before storage and optimize banking efficiency by designing reliable procedures to process and freeze the selected units. Among the different parameters characterizing UCB, nucleated cell (NC) and CD34+ cell content provides useful criteria to select UCB units since clinical data documented that the infused cell load (both NC and CD34+ cells) plays an important role in the successful outcome of transplants. By evaluating volume, CD34+ cell content, NC total amount, and NC density of 117 UCB units, we found a significant association between CD34+ cell content and NC density and total amount, indicating these parameters as useful to decide UCB clinical utility. Furthermore, we set up a fast procedure to process UCB units for storage. A system for NC separation and volume reduction of UCB samples in a dedicated, germ-free, closed circuit was developed, where plasma and red blood cells (RBC) depletion was obtained by sedimentation in the presence of a 3.5% Polygeline solution. By this separation system, both RBC depletion and high NC and CD34+ cell recoveries were achieved in 60 min, and the yield was comparable to the one obtained by other separation methods. Since Polygeline has been clinically used as a plasma expander and no toxic effects on patients were reported, the protocol can be applied in the large-scale banking of UCB.
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Bancos de Sangre , Sangre Fetal/citología , Antígenos CD34/análisis , Conservación de la Sangre , Separación Celular , Células Cultivadas , Ensayo de Unidades Formadoras de Colonias , Criopreservación , Citometría de Flujo , Células Madre Hematopoyéticas/citología , Humanos , Recuento de Leucocitos , Poligelina/química , Manejo de EspecímenesRESUMEN
To explore the effect of fluctuating glucose on endothelial cells, human umbilical vein endothelial cells were incubated for 14 days in media containing different glucose concentrations: 5 mmol/l, 20 mmol/l, or a daily alternating 5 or 20 mmol/l glucose. Apoptosis was studied by different methods: viability assay, cell cycle analysis, DNA fragmentation, and morphological analysis. Furthermore, the levels of Bcl-2 and Bax, well known proteins involved in apoptosis, were evaluated. Stable high glucose induced apoptosis in human umbilical vein endothelial cells, a phenomenon accompanied by a significant decrease of Bcl-2 and a simultaneous increase of Bax expression. However, apoptosis was enhanced in human umbilical vein endothelial cells exposed to intermittent, rather than constant, high glucose concentration. In this condition, Bcl-2 was not detectable, whereas Bax expression was significantly enhanced. These findings suggest that variability in glycemic control could be more deleterious to endothelial cells than a constant high concentration of glucose.
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Apoptosis/efectos de los fármacos , Endotelio Vascular/citología , Glucosa/administración & dosificación , Western Blotting , Ciclo Celular , Supervivencia Celular , Células Cultivadas , Fragmentación del ADN , Electroforesis en Gel de Agar , Endotelio Vascular/efectos de los fármacos , Glucosa/farmacología , Humanos , Proteínas Proto-Oncogénicas/análisis , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/análisis , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Venas Umbilicales , Proteína X Asociada a bcl-2RESUMEN
Cathelicidin-derived antimicrobial peptides are a component of the peptide-based host defense of neutrophils and epithelia, with a widespread distribution in mammals. We recently reported the cDNA sequences of three putative horse myeloid cathelicidins, named eCATH-1, -2, and -3. A Western analysis was performed to investigate their presence in neutrophils and processing to mature peptides. eCATH-2 and eCATH-3, but not eCATH-1, were found to be present in uncleaved forms in horse neutrophils. The corresponding mature peptides were detected in inflammatory sites, suggesting that processing of the propeptides takes place upon neutrophil activation. A functional characterization was then performed with synthetic eCATH peptides. Circular dichroism measurements indicated an amphipathic alpha-helical conformation of these peptides in an anisotropic environment, and in vitro assays revealed a potent activity and a broad spectrum of antimicrobial activity for eCATH-1 and a somewhat more restricted spectrum of activity for eCATH-2. Conversely, a strong dependence on salt concentration was observed when the activity of eCATH-3 was tested. This peptide efficiently killed bacteria and some fungal species, i.e., Cryptococcus neoformans and Rhodotorula rubra, in low-ionic-strength media, but the activity was inhibited in the presence of physiological salt medium. This behavior could be modified by modulating the amphipathicity of the molecule. In fact, the synthetic analogue LLK-eCATH-3, with a slightly modified sequence that increases the hydrophobic moment of the peptide, displayed a potent activity in physiological salt medium against the strains resistant to eCATH-3 under these conditions.
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Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Animales , Antibacterianos/química , Péptidos Catiónicos Antimicrobianos/química , Catelicidinas , Escherichia coli/efectos de los fármacos , Caballos , Humanos , Pruebas de Sensibilidad Microbiana , Péptidos/química , Péptidos/farmacología , Estructura Secundaria de Proteína , Salmonella/efectos de los fármacos , Staphylococcus/efectos de los fármacos , Relación Estructura-ActividadRESUMEN
To obtain long-term engraftment and hematopoiesis in myeloablated patients, the cell population used for hematopoietic reconstitution should include a sufficient number of early pluripotent hematopoietic stem cells (HSCs), along with committed cells from the various lineages. For this purpose, the small subset of CD34+ cells purified from different sources must be expanded ex vivo. Since cytokines may induce both proliferation and differentiation, expansion would provide a cell population comprising committed as well as uncommitted cells. Optimization of HSC expansion methods could be obtained by a combination of cytokines able to sustain renewal of pluripotent cells yet endowed with poor differentiation potential. We used variations of the combinations of cytokines described by Brugger et al. [W. Brugger, S. Heimfels, R. J. Berenson, R. Mertelsmann, and L. Kanz (1995) N. Engl. J. Med. 333, 283-287] and Piacibello et al. [W. Piacibello, F. Sanavio, L. Garetto, A. Severino, D. Bergandi, J. Ferrario, F. Fagioli, M. Berger, and M. Aglietta (1997) Blood 89, 2644-2653] to expand UCB CD34+ cells and monitored proliferation rate and phenotype after 14 days of culture. Several hematopoietic lineage-associated surface antigens were evaluated. Our data show that flt3L and thrombopoietin in combination with IL-3, while sustaining a high CD34+ proliferation rate, provide a relatively low enrichment in very early uncommitted CD34+/CD38- cells. Conversely, in the absence of IL-3, they are less effective in inducing proliferation yet significantly increase the number of CD34+/CD38- cells. A combination of the above protocols, applied simultaneously to aliquots of the same sample, would allow expansion of both committed and pluripotent HSC. This strategy may represent a significant improvement for clinical applications.
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Antígenos CD , Técnicas de Cultivo de Célula/métodos , Trasplante de Células Madre Hematopoyéticas/métodos , Células Madre Hematopoyéticas/citología , ADP-Ribosil Ciclasa , ADP-Ribosil Ciclasa 1 , Antígenos CD34/análisis , Antígenos de Diferenciación/análisis , Diferenciación Celular , División Celular/efectos de los fármacos , Sinergismo Farmacológico , Eritropoyetina/farmacología , Sangre Fetal/citología , Citometría de Flujo , Células Madre Hematopoyéticas/clasificación , Células Madre Hematopoyéticas/efectos de los fármacos , Humanos , Separación Inmunomagnética , Inmunofenotipificación , Recién Nacido , Interleucina-3/farmacología , Interleucina-6/farmacología , Glicoproteínas de Membrana , Proteínas de la Membrana/farmacología , NAD+ Nucleosidasa/análisis , Factor de Células Madre/farmacología , Trombopoyetina/farmacologíaRESUMEN
Antimicrobial peptides are effector molecules of innate immunity that provide a first line of defense against pathogens. In mammals, they are stored in granules of leukocytes and are present in those sites that are exposed to microbial invasion, such as mucosal surfaces and skin. In the last decade, biochemical investigations and recombinant DNA technology have allowed the identification and characterization of several antimicrobial peptides from various animal and vegetal species. Most of the mammalian peptides have been grouped in two broad families: defensins and cathelicidin-derived peptides. Functional studies have shown that the toxicity mechanisms for many peptides consist of a rapid permeabilization of the target cell membrane. In addition to their microbicidal activity, some members of both families are multifunctional molecules, playing a modulating role in the inflammation and the antigen-driven immune response.
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Péptidos Catiónicos Antimicrobianos/fisiología , Inmunidad Innata , Leucocitos/inmunología , Animales , Aniones/química , Péptidos Catiónicos Antimicrobianos/clasificación , Bacterias/química , Catelicidinas , Permeabilidad de la Membrana Celular/efectos de los fármacos , Gránulos Citoplasmáticos/metabolismo , Citotoxicidad Inmunológica , Defensinas/fisiología , Diseño de Fármacos , Humanos , Inflamación/metabolismo , Leucocitos/metabolismo , Mamíferos/inmunología , Mamíferos/metabolismo , Lípidos de la Membrana/química , Ratones , Fagosomas/fisiología , Fosfolípidos/química , Estructura Terciaria de Proteína , Conejos , Ratas , Células Tumorales CultivadasRESUMEN
SMAP-29 is a cathelicidin-derived peptide deduced from sheep myeloid mRNA. The C-terminally amidated form of this peptide was chemically synthesized and shown to exert a potent antimicrobial activity. Antibiotic-resistant clinical isolates highly susceptible to this peptide include MRSA and VREF isolates, that are a major worldwide problem, and mucoid Pseudomonas aeruginosa associated with chronic respiratory inflammation in CF patients. In addition, SMAP-29 is also active against fungi, including Cryptococcus neoformans isolated from immunocompromised patients. SMAP-29 causes significant morphological alterations of the bacterial surfaces, as shown by scanning electron microscopy, and is also hemolytic against human, but not sheep erythrocytes. Its potent antimicrobial activity suggests that this peptide is an excellent candidate as a lead compound for the development of novel antiinfective agents.
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Antibacterianos/farmacología , Antifúngicos/farmacología , Proteínas Sanguíneas , Leucocitos/química , Péptidos , Proteínas/farmacología , Animales , Catelicidinas , Dicroismo Circular , Relación Dosis-Respuesta a Droga , Diseño de Fármacos , Escherichia coli/metabolismo , Hemólisis , Humanos , Cinética , Microscopía Electrónica de Rastreo , Conformación Proteica , Estructura Secundaria de Proteína , Proteínas/química , Ovinos , Staphylococcus aureus/metabolismoRESUMEN
Antimicrobial peptides are present in a wide range of species, from protozoa to man, as effector molecules of innate immunity. Several bovine precursors of antimicrobial peptides have recently been identified, as deduced from cDNA, and assigned to the cathelicidin family. Two of these are the proforms of the antimicrobial peptides BMAP-27 and BMAP-28, which share a similar amino acid sequence, structural conformation, and toxic activity toward several bacterial and fungal strains. Here we report that they are cytotoxic to human tumor cells and normal proliferating, but not resting, lymphocytes at concentrations comparable to those microbiocidal. This effect is primarily due to damage of plasma membrane integrity. A more detailed investigation of the U937 cell line revealed that a Ca2+ influx into the cytosol occurs in the early steps of permeabilization. The perturbation of the membrane structure and the Ca2+ influx are followed by programmed death. A similar apoptosis inducing effect is also observed on in vitro activated human lymphocytes.
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Antiinfecciosos/farmacología , Apoptosis/efectos de los fármacos , Permeabilidad de la Membrana Celular/efectos de los fármacos , Proteínas/farmacología , Secuencia de Aminoácidos , Animales , Citotoxicidad Celular Dependiente de Anticuerpos/efectos de los fármacos , Péptidos Catiónicos Antimicrobianos , Calcio/metabolismo , Línea Celular , Fragmentación del ADN/efectos de los fármacos , Humanos , Linfocitos/efectos de los fármacos , Ratones , Datos de Secuencia MolecularRESUMEN
Cathelicidins are a family of myeloid antimicrobial peptide precursors that have been identified in several mammalian species (Zanetti, M., Gennaro, R., and Romeo, D. (1995) FEBS Lett. 374, 1-5). Two novel bovine congeners have been deduced from cDNA. Their C-terminal sequences of 27 and 28 residues correspond to putative antimicrobial peptides with a cationic N-terminal region predicted to assume an amphipathic alpha-helical conformation followed by a hydrophobic C-terminal tail. Peptides corresponding to these sequences have been chemically synthesized and shown to exert a potent antimicrobial activity against Gram-negative and Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus, and fungi. Both peptides are also cytotoxic to human erythrocytes and neutrophils, although at higher than microbicidal concentrations. The target selectivity has been improved by synthesizing truncated analogues, comprising only the 18 N-terminal residues, which show a great reduction in cytotoxic, but not in antimicrobial activity. The involvement of the C-terminal hydrophobic tail in the cytotoxic activity has been further demonstrated by inducing a major loss of activity in an analogue after replacing highly hydrophobic residues with more hydrophilic ones.
Asunto(s)
Antibacterianos/química , Proteínas/química , Secuencia de Aminoácidos , Animales , Antibacterianos/metabolismo , Péptidos Catiónicos Antimicrobianos , Secuencia de Bases , Northern Blotting , Bovinos , Supervivencia Celular/efectos de los fármacos , Dicroismo Circular , Eritrocitos/efectos de los fármacos , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Conformación Proteica , Proteínas/metabolismo , Relación Estructura-ActividadRESUMEN
Apoptosis seems to be involved in different stages of immune cell development. In particular, experimental evidence suggests that it is a major form of cell death in the thymus. The present analysis of human thymocytes reveals that a fraction of these cells, cultured in vitro, undergoes spontaneous apoptosis. This observation is based both on molecular (DNA fragmentation) and morphological (electron microscopic) investigations of the cells. The apoptotic thymocytes are CD3- or CD3lo, CD4lo, and CD8lo and do not express Bcl-2 protein. Furthermore, thymocytes die by apoptosis when exposed to pharmacological stimuli, such as tumor necrosis factor-alpha, dexamethasone, ATP, or Ca++ ionophore. Thus the apoptotic machinery in thymocytes can be triggered by an imbalance in growth factors in the in vitro culture media and can be modulated by various biochemical signals. The process of spontaneous apoptosis is independent of mRNA or protein synthesis, as actinomycin D and cycloheximide fail to inhibit this phenomenon. Furthermore, apoptosis seems to require active oxidative phosphorylation, as it is prevented by incubation of the cells with inhibitors of the respiratory chain.
Asunto(s)
Apoptosis , Timo/citología , Preescolar , Humanos , Lactante , Recién Nacido , Subgrupos Linfocitarios/fisiología , Microscopía Electrónica , Consumo de Oxígeno , Fenotipo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2 , Estimulación Química , Timo/fisiologíaRESUMEN
Monoclonal antibodies (mAbs) against cultured human ovary carcinoma cells were produced. We obtained 7 mAbs which reacted diffusely with carcinoma of the ovary but only weakly with vessels and the surface epithelial layer of normal ovary. Biochemical characterization of these mAbs indicated that 3 out of 7 were specific for the alpha 3 chain of the Vla-3 integrin, a receptor for fibronectin, collagen and laminin. Using one of these mAbs, we have studied, by immunohistochemical methods, the distribution of alpha 3 beta 1 integrin in mucinous, serous and endometrioid cystoadenocarcinoma of the ovary and in their normal equivalent: endocervical, tubal and endometrial epithelia. The results show that alpha 3 beta 1 is present in cell-cell contact areas and more abundantly at the junction between epithelial cells and basement membrane in endocervical, tubal epithelia, in epithelium lining the cavity of the uterus and in surface epithelium of the ovary. However, endometrial glands showed only weak and fragmented positivity at the basal pole of the cells. 26 out of 31 ovarian cancers studied, expressed the alpha 3 beta 1 integrin. However, basal localization, typical of normal epithelia, is not prominent or disappears in tumors and is replaced by a more diffuse reaction with variable immunohistochemical staining of the neoplastic cells. Furthermore, a comparative analysis of the expression of alpha 3 beta 1 and its ligands, laminin (LM), fibronectin (FN) and collagen IV (Coll IV), demonstrated that basal polarization of Vla-3 was always correlated with the presence of laminin and Coll IV, intrinsic components of the basement membranes.