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The recent biological invasion of box tree moth Cydalima perspectalis on Buxus trees has a major impact on European boxwood stands through severe defoliation. This can hinder further regrowth and threaten survival of populations. In a mesocosm approach and controlled larval density over a 2-month period, responses of B. sempervirens essential and specialized metabolites were characterized using metabolomics, combining 1H-NMR and LC-MS/MS approaches. This is the first metabolome depiction of major Buxus responses to boxwood moth invasion. Under severe predation, remaining green leaves accumulate free amino acids (with the noticeable exception of proline). The leaf trans-4-hydroxystachydrine and stachydrine reached 10-13% and 2-3% (DW), while root content was lower but also modulated by predation level. Larval predation promoted triterpenoid and (steroidal) alkaloid synthesis and diversification, while flavonoids did not seem to have a relevant role in Buxus resistance. Our results reveal the concomitant responses of central and specialized metabolism, in relation to severity of predation. They also confirm the potential of metabolic profiling using 1H-NMR and LC-MS to detect re-orchestration of metabolism of native boxwood after severe herbivorous predation by the invasive box-tree moth, and thus their relevance for plant-insect relationships and ecometabolomics.
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This review of the historical medical literature aimed at understanding the evolution of surgical management of degenerative spondylolisthesis over time. The Medic@, IndexCat and Gallica historical databases and PubMed and Embase medical databases were used, with several search-terms, exploring the years 1700-2018. Data from anatomical, biomechanical, pathophysiological and surgical studies were compiled. In total, 150 documents were obtained, dating from 1782 to 2018: 139 from PubMed, 1 from Medic@, 7 from IndexCat, and 3 from Gallica. The review thus ranges in time from (1) description of the first clinical cases by several authors in Europe (1782), (2) the identification of a distinct entity by MacNab (1963), and (3) surgical management by the emerging discipline of minimally invasive spine surgery, to its subsequent evolution up to the present day. Spondylolisthesis is a frequent condition potentially responsible for a variety of functional impairments. Understanding and surgical management have progressed since the 20th century. Historically, the first descriptions of treatments concerned only spondylolisthesis associated with spondylolysis, especially in young adults. More recently, there has been progress in the understanding of the disease in elderly people, with the recognition of degenerative spondylolisthesis. New technologies and surgical techniques, aided by advances in supportive care, now provide spine surgeons with powerful treatment tools. Better knowledge of the evolution of surgery throughout history should enable better understanding of current approaches and concepts for treating degenerative spondylolisthesis.
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Procedimientos Neuroquirúrgicos/métodos , Espondilolistesis/patología , Espondilolistesis/cirugía , Humanos , Fusión VertebralRESUMEN
BACKGROUND: Brain metastases occur in 15-30% of cancer patients and their frequency has increased over time. They can cause intracranial hypertension, even in the absence of hydrocephalus. Emergency surgical management of brain metastasis-related intracranial hypertension is not guided by specific recommendations. OBJECTIVE: We aimed to make a French national survey of emergency management of intracranial hypertension without hydrocephalus in the context of cerebral metastasis. METHODS: A national online survey of French neurosurgeons from 16 centers was conducted, consisting of three clinical files, with multiple-choice questions on diagnostic and therapeutic management in different emergency situations. RESULTS: In young patients without any previously known primary cancer, acute intracranial hypertension due to a seemingly metastatic single brain tumor indicated emergency surgery for all those interviewed; 61% aimed at complete resection; brain MRI was mandatory for 74%. When a primary cancer was known, 74% of respondents were more likely to propose surgery if an oncologist confirmed the possibility of adjuvant treatment; 27% were more likely to operate on an emergency basis when resection was scheduled after multi-disciplinary discussion, prior to acute degradation. CONCLUSION: Currently, there is no consensus on the emergency management of intracranial hypertension in metastatic brain tumor patients. In case of previously known primary cancer, a discussion with the oncology team seems necessary, even in emergency. Decision criteria emerge from our literature review, but require analysis in further studies.
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Neoplasias Encefálicas/complicaciones , Neoplasias Encefálicas/cirugía , Hipertensión Intracraneal/etiología , Hipertensión Intracraneal/cirugía , Enfermedad Aguda , Quimioradioterapia Adyuvante , Servicios Médicos de Urgencia , Francia , Humanos , Metástasis de la Neoplasia , Neoplasias Primarias Desconocidas , Neurocirujanos , Grupo de Atención al Paciente , Encuestas y CuestionariosRESUMEN
BACKGROUND: The present study developed 3D video tutorials with commentaries, using virtual reality headsets (VRH). VRHs allow 3D visualization of complex anatomy from the surgeon's point of view. Students can view the surgery repeatedly without missing the essential steps, simultaneously receiving advice from a group of experts in the field. METHODS: A single-center prospective study assessed surgical teaching using 3D video tutorials designed for French neurosurgery and ENT residents participating in the neuro-otology lateral skull-base workshop of the French College of Neurosurgery. At the end of the session, students filled out an evaluation form with 5-point Likert scale to assess the teaching and the positive and negative points of this teaching tool. RESULTS: Twenty-two residents in neurosurgery (n=17, 81.0%) and ENT (n=5) were included. Eighteen felt that the 3D video enhanced their understanding of the surgical approach (81.8%). Fifteen (68.2%) thought the video provided good 3D visualization of anatomical structures and 20 that it enabled better understanding of anatomical relationships (90.9%). Most students had positive feelings about ease of use and their experience of the 3D video tutorial (n=14, 63.6%). Twenty (90.9%) enjoyed using the video. Twelve (54.5%) considered that the cadaver dissection workshop was more instructive. CONCLUSIONS: 3D video via a virtual reality headset is an innovative teaching tool, approved by the students themselves. A future study should evaluate its long-term contribution, so as to determine its role in specialized neurosurgery and ENT diploma courses.
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Imagenología Tridimensional/métodos , Neurocirugia/educación , Realidad Virtual , Recursos Audiovisuales , Simulación por Computador , Evaluación Educacional , Francia , Humanos , Internado y Residencia , Estudios Prospectivos , Base del Cráneo/anatomía & histología , Base del Cráneo/cirugía , EnseñanzaRESUMEN
In alpine ecosystems, tannin-rich-litter decomposition occurs mainly under snow. With global change, variations in snowfall might affect soil temperature and microbial diversity with biogeochemical consequences on ecosystem processes. However, the relationships linking soil temperature and tannin degradation with soil microorganisms and nutrients fluxes remain poorly understood. Here, we combined biogeochemical and molecular profiling approaches to monitor tannin degradation, nutrient cycling and microbial communities (Bacteria, Crenarcheotes, Fungi) in undisturbed winter time soil cores exposed to low temperature (0 degrees C/-6 degrees C), amended or not with tannins, extracted from Dryas octopetala. No toxic effect of tannins on microbial populations was found, indicating that they withstand phenolics from alpine vegetation litter. Additionally at -6 degrees C, higher carbon mineralization, higher protocatechuic acid concentration (intermediary metabolite of tannin catabolism), and changes in fungal phylogenetic composition showed that freezing temperatures may select fungi able to degrade D. octopetala's tannins. In contrast, negative net nitrogen mineralization rates were observed at -6 degrees C possibly due to a more efficient N immobilization by tannins than N production by microbial activities, and suggesting a decoupling between C and N mineralization. Our results confirmed tannins and soil temperatures as relevant controls of microbial catabolism which are crucial for alpine ecosystems functioning and carbon storage.
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Biodiversidad , Ecosistema , Microbiología del Suelo , Suelo/análisis , Taninos/metabolismo , Bacterias/metabolismo , Carbono/metabolismo , Hongos/metabolismo , Hongos/fisiología , Estaciones del Año , Taninos/farmacologíaRESUMEN
ADP, a primary stimulus of platelets, binds to one or more populations of receptors on the platelet surface. These receptors are linked to discrete activation pathways. Both G proteins and tyrosine kinases have been implicated in the cellular responses to this agonist. We have studied a patient with a congenital abnormality of ADP-induced platelet aggregation in an effort to gain information on the signalling pathways used by ADP. Immunoblotting with a broadly reactive rabbit antibody recognizing the GTP-binding domain of G protein alpha-subunits, and with rabbit antibodies specific for Gialpha1-3, and Galpha12 all showed normal reactivity when tested against the patient's platelets. The phosphorylation of proteins was studied using an anti-phosphotyrosine MoAb (4G10) and platelets stimulated in a platelet aggregometer with ADP, a thromboxane A2 mimetic (IBOP), TRAP-14-mer peptide and alpha-thrombin. With normal platelets, a time-dependent phosphorylation of several bands in the 60 to 130 kDa mol. wt. range was observed with all agonists. For the patient, minimal aggregation and little or no phosphorylation of proteins of 80-85 kDa (cortactin), 100-105 kDa and 125-130 kDa were seen in response to ADP. The aggregation and phosphorylation responses were slightly modified in the presence of low doses of thrombin but were normal with high doses. Aggregation and tyrosine phosphorylation were virtually absent with IBOP, a finding reproduced when normal platelets were incubated with IBOP and the CP/CPK ADP scavenging system, thereby underlining the role of ADP in the response to IBOP. Our results show that the ADP receptor pathway deficient in the patient is linked to a selective tyrosine phosphorylation response.
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Adenosina Difosfato/metabolismo , Plaquetas/fisiología , Receptores Purinérgicos P2/metabolismo , Transducción de Señal/fisiología , Tirosina/metabolismo , Animales , Fosforilación , Activación Plaquetaria , ConejosRESUMEN
Vitamin B1, B2, B6, C, A, and E status was assessed by combining determination of dietary intake with biochemical indices in 55 young male athletes. When compared with 20 matched sedentary controls, a similar number of individuals with biochemical deficiency was found in both groups for vitamins B1, B6, and E despite a higher mean dietary intake of these three vitamins in young athletes. Markedly reduced levels of pyridoxal 5'-phosphate, the biologically active form of the vitamin B6 compounds, were found in both populations. Supplementation administered for one month improved the vitamin status of the control subjects but not entirely those of the young athletes.
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Deportes , Vitaminas/metabolismo , Adulto , Avitaminosis/epidemiología , Encuestas sobre Dietas , Estudios de Evaluación como Asunto , Humanos , MasculinoRESUMEN
Reduction of carbaryl solution by zero-valent iron powder (ZVIP) was studied in a rotator batch system (70 rpm) in order to evaluate the utility of this reaction in remediation of carbamate contaminated water. Degradation with different amount of ZVIP: 0.01, 0.02, 0.03, 0.04 g/ml at pH 6.6 and at ambient temperature was investigated. The results show that the process exhibits a degradation rate appearing to be directly proportional to the surface contact area of ZVIP (325-mesh) with the carbaryl molecules. Three analytical techniques were used to monitor carbaryl degradation: (1) A UV-Vis diode array spectrophotometer was used to record all spectra. (2) A high performance liquid chromatography was used to separate by-products and examine the evolution of breakdown products. (3) A home-built spectrophosphorimeter that uses the solid surface room temperature phosphorescence (SSRTP) was employed to observe selectively the decline of the carbaryl concentration at different amount of ZVIP on Whatman no. 1 filter paper. Results show that the reducing degradation of carbaryl with ZVIP as the source of electrons is effective with a half-life close to several minutes.
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Carbaril/aislamiento & purificación , Insecticidas/aislamiento & purificación , Absorción , Carbaril/química , Cromatografía Líquida de Alta Presión/métodos , Cromatografía Liquida , Insecticidas/química , Hierro/química , Espectrofotometría/métodos , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
This observation reports the case of a soft tissue tumor occurring in a 11 years-old boy. On standard histologic staining, this tumor corresponded to an undifferentiated sarcoma of high grade of malignancy. Immuno-histochemical features (laminin, vimentin, UEA I and Factor VIII R-ag) and ultrastructural analysis (presence of Weibel-Palade bodies) led us to the diagnosis of angiosarcoma. This tumor is rarely reported in children and its prognosis remains unknown. Soft tissue angiosarcoma must be differentiated from Kaposi's sarcoma, epithelioid hemangioendothelioma, hemangiopericytoma and spindle cell hemangioendothelioma. This case stresses the importance of immunohistochemical and ultra-structural features in the diagnosis of poorly differentiated vascular neoplasms.
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Hemangiosarcoma/patología , Neoplasias de los Tejidos Blandos/patología , Diferenciación Celular/fisiología , Niño , Hemangiosarcoma/química , Hemangiosarcoma/ultraestructura , Humanos , Técnicas para Inmunoenzimas , Masculino , Neoplasias de los Tejidos Blandos/química , Neoplasias de los Tejidos Blandos/ultraestructuraRESUMEN
The authors have studied 135 case histories of extra-uterine pregnancies which were operated on and followed up the years 1965-1973. They draw attention to: 1. At the clinical level atypical symptoms are found in 29% of cases, which means that the diagnosis is made late in many cases (36% of ruptured tubes) in spite of modern methods of diagnosis. 2. As far as the woman's obstetrical future is concerned they note the low level of further conceptions (51%), the rarity of pregnancies that go to term (24%), and the importance of complication (15%). Fertility after extra-uterine pregnancy is higher when the woman has already had children (43%) as against those women whose extra-uterine pregnancy is in their first pregnancy (25%). They suggest that these results can be improved if on top of surgical treatment further medical supportive treatment is given such as antibiotics, steroids and postoperative hydrotubation.
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Embarazo Ectópico/diagnóstico , Femenino , Fertilidad , Humanos , Infertilidad Femenina , Paridad , Embarazo , Embarazo Ectópico/cirugía , PronósticoRESUMEN
BACKGROUND: Shewanella alga is a Gram-negative bacilla often found in water or soil. Clinical infections in humans are rare, with serious infections described generally in immunocompromised hosts. CASE REPORT: A 66 year-old man with a heel wound had developed, after numerous sea baths in the Atlantic ocean (Oleron island, France), an infectious cellulitis of the leg with Shewanella alga septicemia. Despite the absence of immunodeficiency in this patient, infectious cellulitis and septicemia occurred via a wound to the skin and contact with sea water. Healing was seen after treatment with cefotaxime, ciprofoxacin and gentamicin IV, relayed with ciprofloxacin and erythromycin. Shewanella alga was also susceptible to ticarcillin, piperacillin and ceftazidime but was resistant to ampicillin, amoxicilline-clavulanate, colistin, cyclines, fosfomycin and cefsulodin. No immunological anomaly was found. DISCUSSION: We report a case of infectious cellulitis with Shewanella alga septicemia. This has not previously been described in an immunocompetent patient. Antibiotic therapy must be longer than usual treatment for streptococcal erysipelas and first-line antibiotherapy with ampicillin alone may not be sufficient.
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Celulitis (Flemón)/microbiología , Infecciones por Bacterias Gramnegativas/complicaciones , Sepsis/microbiología , Shewanella , Enfermedad Aguda , Anciano , Humanos , Inmunocompetencia , MasculinoRESUMEN
OBJECTIVE: The authors wanted to assess the level of Streptococcus pneumoniae antibiotic resistance in Ile de France. METHOD: In 2001, 637 clinical strains of S. pneumoniae were prospectively collected from 32 microbiology laboratories. RESULTS: Fifty one percent of strains were isolated from children under 15 years of age and 49% from adults. In children, 76% of strains came from otitis media, 20% from blood culture, in adults most strains (92%) came from blood culture. The overall prevalence of non-susceptible penicillin pneumococci was 61% higher in children (73%) than in adults (50%). Among the non-susceptible penicillin pneumococci 21.8% were resistant (CMI > 1 mg/l). Strains with decreased susceptibility to amoxicillin and cefotaxime were 38% and 17% respectively. Resistant strains to these two drugs (CMI > 2 mg/l) were rare 2.6% and 0.4% respectively. Among other antimicrobial agents, rate of resistance was 63% to erythromycin, 47% to cotrimoxazole, 40% to tetracycline, and 23% to chloramphenicol. The most frequent serogroups were serogroups 19 and 14, respectively 23% and 18%. Serotypes included in heptavalent vaccine covered 90% of children strains under 2 years of age. CONCLUSIONS: The prevalence of resistance to penicillin was high in children particularly in otitis media pus (76%).
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Infecciones Neumocócicas/tratamiento farmacológico , Infecciones Neumocócicas/epidemiología , Streptococcus pneumoniae/efectos de los fármacos , Adulto , Niño , Farmacorresistencia Bacteriana , Francia/epidemiología , Humanos , Prevalencia , Estudios Prospectivos , Streptococcus pneumoniae/aislamiento & purificaciónRESUMEN
In humans, assessment of the sympathetic component of the arterial baroreceptor reflex (sBRS) is usually based on microneurographic recordings of muscle sympathetic nerve activity (MSNA), while inducing reflex changes with intravenous administration of vasoactive drugs (modified Oxford method). This method has several limitations, among which its poor temporal resolution. Some studies have proposed alternative methods by using spontaneous changes in arterial pressure (AP) and MSNA, usually collected under baroreflex closed-loop conditions (AP alters MSNA while MSNA alters AP), which makes the results difficult to interpret. In rats, a method has been developed and validated (Kanbar et al., 2007 [1]), which uses oscillations of renal SNA at the frequency of the heart beat. At this frequency, the baroreflex operates under open-loop conditions because of the low-pass filter properties of the resistance vasculature. The goal of the present study was to examine whether this method is applicable in humans. Data were previously collected by Gujic et al. (2007) [2]. Briefly, MSNA and AP were recorded in 16 young healthy subjects during a 5-minute baseline resting period then during a modified Oxford test (sodium nitroprusside and phenylephrine administrations). Using the 5-minute baseline recordings, spontaneous sBRS was assessed through empirical mode decomposition over consecutive 20-second periods. Spontaneous sBRS was significantly related to pharmacological sBRS (R=0.67, n=16, P=0.004). During the 5-minute period, spontaneous sBRS exhibited variations (CV=21.7±1.7%) that were negatively correlated with AP in five subjects (R=-0.61±0.03, P<0.05) and positively correlated with MSNA in ten subjects (R=0.73±0.03, P<0.05). The new method is able to correctly estimate sBRS, and reveals the existence of previously unrecognized fast fluctuations of sBRS.
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Presión Arterial , Barorreflejo/efectos de los fármacos , Sistema Nervioso Simpático/fisiología , Adulto , Algoritmos , Animales , Presión Arterial/efectos de los fármacos , Humanos , Modelos Lineales , Músculos/inervación , Nitroprusiato/farmacología , Nervio Peroneo/fisiología , Fenilefrina/farmacología , Fotopletismografía/métodos , Ratas , Reproducibilidad de los Resultados , Proyectos de Investigación , Vasoconstrictores/farmacología , Vasodilatadores/farmacologíaRESUMEN
Regeneration failure ofPicea abies in a subalpine bilberry-spruce forest was studied in relation to phenolic compounds, their occurrence and toxicity. Germination bioassays with natural leachates of bilberry (Vaccinium myrtillus) and spruce showed negative effects on root elongation of spruce seedlings. Growth bioassays on litter and humus demonstrated inhibitory effects of these organic layers.p-Hydroxyacetophenone, a spruce-specific metabolite, was isolated in spruce throughfall (10(-6) M), in water extracts of litter (between 1 and 8 µg/g dry wt) and organic layer (less than 1 µg/g dry wt) in addition to tannins and several common phenolic acids. Potential relationships between vegetation cover and phenolic pattern of the soil are discussed, since organic layers under bilberry heath exhibited higher amounts of phenolic acids and tannins than those under spruce.p-Hydroxyacetophenone and caffeic acid reduced, even at 5 × 10(-5) M, spruce seedling growth, especially root development, with additive effects for these two monomers. Autotoxicity involving spruce trees and allelopathy of understory species, mediated byp-hydroxy-acetophenone and other phenolic compounds, including tannins, deserves further attention in regeneration studies.
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CE145-66 is an improved early-maturing grain sorghum genotype, increasingly grown by farmers in the Sahelian part of Senegal. This genotype is known to have negative effects on the following groundnut crop, because of the release of allelopathic phenolic compounds into the soil. We have assessed the synthesis of phenolics in sorghum vegetative parts and the variations in synthesis between years and sites. Total phenols and phenolic acids in the aerial parts and roots of flowering sorghum plants from 52 farmers' fields at two sites (Sagnanème and Médina) in Senegal in 1996 and 1997 were measured. Thirty-eight soil samples, collected after the sorghum harvest, from sorghum rows and interrows also were analyzed for their phenolic content. Total phenols reached 1.1-1.5% of root dry weight and 1.1-2.2% of aerial parts dry weight, with little variation between sites, and large variability between years, presumably due to climatic conditions. Eight phenolic acids and three associated aldehydes were identified by HPLC, with p-hydroxybenzoic, p-coumaric, and ferulic acids the most abundant. Their totals reached 2.9-3.2 mg/g in 1996 and 2.6-2.8 mg/g in 1997 for the aerial part; and 3.3-3.6 mg/g in 1996 and 2.8-3.3 mg/g in 1997 for roots. In soils under sorghum rows, the mean water-soluble total phenols increased from 4.6 in 1997 to 6.7 micrograms/g in 1998 in Sagnanème, and from 3.8 in 1997 to 5 micrograms/g in 1998 in Médina. The concentrations of total phenols and phenolic acids were higher in rows than in interrows. All the phenolic monomers identified in vegetative parts were recovered in associated soil samples, with vanillic and p-hydroxybenzoic acids the most abundant. Finally, variability in plant phenolic content seemed more due to climatic than to cropping or soil factors, as differences between years appear more important than differences between or within sites.
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Flavonoides , Magnoliopsida/química , Magnoliopsida/genética , Fenoles/análisis , Suelo , Genotipo , Polímeros/análisis , Polifenoles , Estaciones del Año , Solubilidad , AguaRESUMEN
Thromboxane A(2) (TxA(2)) is a potent vasoconstrictor and platelet agonist. Pharmacological studies have defined two classes of thromboxane receptors (TPs) in human platelets; sites that bind the agonist 1S-(1,2(5Z),3-(1E,3S),4)-7- 3-(3-hydroxy-4-(4'-iodophenoxy)-1-butenyl)-7-oxabicyclo-2.2. 1-heptan-2-yl-5-heptenoic acid (I-BOP) with high affinity support platelet shape change, whereas low affinity sites that bind irreversibly the antagonist GR 32191 transduce platelet aggregation. As the mechanisms of signal transduction involved in platelet aggregation begin to be elucidated, few results concern those involved in platelet shape change, which is independent of the engagement of GPIIb/IIIa. To elucidate the respective role of the two classes of pharmacological binding sites of TPs in shape change, platelets were incubated with I-BOP at low concentrations or stimulated by I-BOP at high concentrations after pretreatment with GR 32191 or activated with low concentrations of 8-epi-prostaglandin F(2)alpha. Under these three conditions, there is a rapid stimulation of protein tyrosine phosphorylation of the 80/85-kDa doublet identified as the cytoskeletal protein cortactin. Tyrosine phosphorylation of cortactin is kinetically correlated with the occurrence of shape change. These biochemical and morphological events are both inhibited by SQ 29548, a TP antagonist, indicating the specificity of the signal. Since tyrosine kinase Syk was activated early during platelet activation, we examined the possibility that cortactin is a potential substrate of Syk in TxA(2)-induced platelet shape change. p72 Syk phosphorylation and kinase activity took place during the period when platelets were changing shape upon low concentrations of I-BOP stimulation. Furthermore, cortactin was associated with Syk, and this association increases along with the level of phosphorylation. These data suggest a novel pathway for a G protein-coupled TxA(2) high affinity receptor to the protein-tyrosine kinase Syk, which is associated with cortactin in the very early steps of platelet activation.
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Plaquetas/efectos de los fármacos , Precursores Enzimáticos/metabolismo , Proteínas de Microfilamentos/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Tromboxanos/farmacología , Tirosina/metabolismo , Plaquetas/citología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Cortactina , Citocalasina D/farmacología , Activación Enzimática , Inhibidores Enzimáticos/farmacología , Precursores Enzimáticos/antagonistas & inhibidores , Ácidos Grasos Insaturados/farmacología , Humanos , Péptidos y Proteínas de Señalización Intracelular , Fosforilación , Activación Plaquetaria/efectos de los fármacos , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Quinasa SykRESUMEN
To assess the efficacy of subcutaneous tunneling, we randomly designated 212 central venous catheters for tunneling (107 catheters) or for standard insertion (105 catheters) in 169 immunocompromised patients. The patients who received tunneled catheters (TCs) and the patients who received nontunneled catheters (NTCs) were similar with respect to age, gender, underlying disease, incidence of leukopenic episodes, receipt of blood product transfusions or parenteral nutrition, and medical care and attendants. The life span of catheters was 112.5 +/- 9.5 days in the TC group and 119 +/- 9 days in the NTC group (P = .5). Clinically relevant bacteremia occurred in 26 cases in the TC group (0.22 episode per 100 catheter-days), a rate not significantly different from that in the NTC group (25 episodes; 0.20 episode per 100 catheter-days). Catheter-related bacteremia was documented in seven cases and non-catheter-related bacteremia in five cases. In most instances, the precise origin of the septic episode could not be determined. Cutaneous infection and bacteremia were associated with the same microorganism in two cases in each group. Since the present study failed to demonstrate any clinical benefit of subcutaneous tunneling, such a procedure is no longer performed in our hospital.