Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Klin Padiatr ; 224(3): 166-9, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22441805

RESUMEN

Thromboembolic complications in infants with congenital heart defects are common despite inhibition of platelet function with acetylsalicylic acid (ASS). Yet there is still insufficient pharmacologic data on the use of clopidogrel in infants. The adult dose of 75 mg/d is significantly higher than the dose lately recommended in infants (0.2 mg/kg/d). Moreover, we know of nonresponders to both acetylsalicylic acid and clopidogrel. Normal coagulation tests fail to identify those patients.Prospective monocentric study on 14 children (median age 5, range 0.7-84 months, 9 male, 5 female). Shunt thrombosis had occurred in 4 infants on ASS therapy. Seven days after starting clopidogrel (0.2 mg/kg/d), platelet function was tested by stimulation with ADP (4 and 10 µmol/l). We considered the range for the clopidogrel effect to be optimal if the maximum aggregation on ADP 4 µmol/l was between 30-50%.Clopidogrel 0.18-0.24 mg/kg/d in addition to ASS 2-4 mg/kg/d resulted in effective inhibition of platelet function in 93% (ADP 4 µmol/l: median 38%, range 30-63). All patients were responders. We observed neither any thromboembolic events nor severe bleeding episodes during the median 11-month follow-up period (range 1-30 mo).Testing platelet function makes clopidogrel dosing safer, and simplifies therapy adjustments in long-term treatment. A clopidogrel dose of 0.2 mg/kg/d was safe and effective in combination with ASS in this small patient cohort.


Asunto(s)
Cardiopatías Congénitas/tratamiento farmacológico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Tromboembolia/prevención & control , Ticlopidina/análogos & derivados , Aspirina/uso terapéutico , Niño , Preescolar , Clopidogrel , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Femenino , Cardiopatías Congénitas/sangre , Humanos , Lactante , Masculino , Inhibidores de Agregación Plaquetaria/efectos adversos , Pruebas de Función Plaquetaria , Estudios Prospectivos , Tromboembolia/sangre , Tromboembolia/etiología , Ticlopidina/efectos adversos , Ticlopidina/uso terapéutico
2.
Biomed Phys Eng Express ; 8(2)2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34933285

RESUMEN

Diabetic peripheral neuropathy (DPN) is associated with loss of motor units (MUs), which can cause changes in the activation pattern of muscle fibres. This study investigated the pattern of muscle activation using high-density surface electromyography (HD-sEMG) signals from subjects with type 2 diabetes mellitus (T2DM) and DPN. Thirty-five adults participated in the study: 12 healthy subjects (HV), 12 patients with T2DM without DPN (No-DPN) and 11 patients with T2DM with DPN (DPN). HD-sEMG signals were recorded in the tibialis anterior muscle during an isometric contraction of ankle dorsiflexion at 50% of the maximum voluntary isometric contraction (MVIC) during 30-s. The calculated HD-sEMG signals parameters were the normalised root mean square (RMS), normalised median frequency (MDF), coefficient of variation (CoV) and modified entropy (ME). The RMS increased significantly (p = 0.001) with time only for the DPN group, while the MDF decreased significantly (p < 0.01) with time for the three groups. Moreover, the ME was significantly lower (p = 0.005), and CoV was significantly higher (p = 0.003) for the DPN group than the HV group. Using HD-sEMG, we have demonstrated a reduction in the number of MU recruited by individuals with DPN. This study provides proof of concept for the clinical utility of this technique for identifying neuromuscular impairment caused by DPN.


Asunto(s)
Diabetes Mellitus Tipo 2 , Neuropatías Diabéticas , Músculo Esquelético/fisiopatología , Adulto , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/fisiopatología , Neuropatías Diabéticas/diagnóstico , Neuropatías Diabéticas/fisiopatología , Humanos , Contracción Isométrica
5.
Klin Padiatr ; 222(3): 168-74, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20514622

RESUMEN

BACKGROUND: Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder causing oculocutaneous albinism, bleeding disorder and ceroid lipofuscinosis. Platelets from HPS patients are characterized by the absence of dense (delta)-bodies. There are eight known human HPS GENES (HPS1-HPS8), each leading to a particular clinical HPS subtype. Restrictive lung disease, granulomatous colitis and cardiomyopathy have been described in HPS1 patients. PATIENTS: We identified HPS1 in Russian and in German siblings. All four patients show a typical HPS phenotype. The two older Russian patients demonstrate excessive bleeding after tooth extractions, recurrent epistaxis and hematomas. The two younger German patients suffer only from hematomas, so far. METHODS/RESULTS: Patients' platelets showed severe pathological agglutination/aggregation. Flow cytometry analysis demonstrated absence of platelet delta-granule secretion. Three different mutations in the HPS1 gene were found in the two families. Two mutations, p.H119delC and p.Q397delC identified in the Russian siblings had been previously described. The German siblings presented with a novel frameshift mutation (p.Q32_S33delCAGT) and the known p.Q397delC mutation. CONCLUSION: Patients with oculocutaneous albinism should be investigated for increased clinical bleeding symptoms. In case of increased bleeding symptoms, analyses of primary hemostasis should be initiated to confirm HPS. Molecular genetic investigations should be performed to distinguish the different subtypes of HPS which is important for therapy and prognosis.


Asunto(s)
Análisis Mutacional de ADN , Tamización de Portadores Genéticos , Genotipo , Síndrome de Hermanski-Pudlak/genética , Adulto , Edad de Inicio , Alelos , Tiempo de Sangría , Niño , Preescolar , Deleción Cromosómica , Codón sin Sentido/genética , Exones , Femenino , Mutación del Sistema de Lectura/genética , Síndrome de Hermanski-Pudlak/sangre , Humanos , Masculino , Linaje , Fenotipo , Pruebas de Función Plaquetaria , Análisis de Secuencia de ADN , Adulto Joven
6.
Hamostaseologie ; 29(2): 168-70, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19404513

RESUMEN

UNLABELLED: Heparin-induced thrombocytopenia (HIT II) in childhood is rare. Suspected HIT II requires immediate diagnostic and therapeutic measures in order to avoid potentially life threatening complications. Heparin must be stopped immediately. We report on a 6-year old boy who required cardiac surgery due to tetralogy of Fallot. To our knowledge he had been exposed to heparin for the first time during cardiac catheterization on the day before surgery. Preoperatively, platelet count was normal. Postoperatively (3 days after heparin exposure), he developed pulmonary and renal failure and required inotropic cardiac support and dialysis. He also developed progressive (severe) thrombocytopenia under heparin therapy on day 2-3 postoperatively. The dialysis filter required daily exchanges due to clotting despite increasing heparin doses. The first ELISA for HIT on postop day 4 was negative. 3 days later a repeated test was positive. Von Willebrand factor antigen and D-dimers were markedly increased. The patient was immediately switched to lepirudin and subsequently stabilized slowly. No major systemic thrombosis occurred. After lepirudin treatment for 6 weeks the patient was fully recovered and HIT II-testing was negative again. CONCLUSION: In children with progressive thrombocytopenia in the setting of heparin exposure and signs of major or micro thrombosis HIT II must be ruled out. Even if a first early test turns out negative repeated testing should be performed. Lepirudin anticoagulation is effective and should be monitored correctly. Platelet transfusion should be avoided in HITII.


Asunto(s)
Anticoagulantes/uso terapéutico , Heparina/efectos adversos , Tetralogía de Fallot/cirugía , Trombocitopenia/inducido químicamente , Trombocitopenia/tratamiento farmacológico , Niño , Hirudinas , Humanos , Masculino , Periodo Posoperatorio , Proteínas Recombinantes/uso terapéutico , Resultado del Tratamiento
10.
Free Radic Biol Med ; 31(10): 1191-7, 2001 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-11705697

RESUMEN

It has been documented that alpha-phenyl-N-tert-butyl-nitron (PBN) possesses a potent neuroprotective effect when administered after transient focal cerebral ischemia. However, contradicting results were reported regarding its effect in transient global ischemia. To further elucidate the mechanism of PBN action, we have studied the effect of PBN on animal survival, histopathological outcome, and activation of caspase-3 following 30 min of global ischemia in vehicle- and PBN-treated rats. The results showed that 30 min of global ischemia was such a severe insult that no animal could survive beyond 2 d of reperfusion. Histopathological evaluation showed severe tissue edema and microinfarct foci in the neocortex and thalamus. Close to 100% damage was observed in the stratum and hippocampal CA1, CA3, and dentate gyrus subregions. Postischemic PBN treatment significantly enhanced animal survival and reduced damage in the neocortex, thalamus, and hippocampus. Immunohistochemistry demonstrated that caspase-3 was activated following ischemia in the striatum and the neocortex. PBN suppressed the activation of caspase-3 in both structures. It is concluded that PBN is a potent neuroprotectant against both focal and global ischemia; besides its function as a free radical scavenger, PBN may reduce ischemic brain damage by blocking cell death pathways that involve caspase-3 activation.


Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Inhibidores de Caspasas , Fármacos Neuroprotectores/uso terapéutico , Óxidos de Nitrógeno/uso terapéutico , Animales , Isquemia Encefálica/patología , Caspasa 3 , Óxidos N-Cíclicos , Modelos Animales de Enfermedad , Masculino , Ratas , Ratas Wistar , Detección de Spin , Tasa de Supervivencia
11.
J Comp Neurol ; 424(4): 718-30, 2000 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-10931492

RESUMEN

The evolutionary position of tarsiers with respect to primates is still debated. The type of photoreceptors in the nocturnal Tarsius spectrum retina has been compared with the nocturnal New World monkey Aotus trivulgaris and the Old World monkey Macaca nemestrina by using immunocytochemical labeling for antisera known to be specific for primate cone and rod proteins. In all three species, antisera to long/medium (L/M) -wavelength specific cone opsin and cone-specific alpha-transducin detected a single row of cones. Only Macaca and tarsier retina contained cones labeled by antiserum to short (S) -wavelength specific cone opsin. Tarsier rod cell bodies were 6-12 deep, depending on retinal eccentricity. Tarsier central cones had 2-microm-wide outer (OS) and inner segments, which came straight off the cell body. Cone morphology differed little from rods except OS were shorter. Macaca cones labeled for 7G6 and calbindin, Aotus cones did not label for calbindin, and Tarsius cones did not label for 7G6 or calbindin. In tarsier retinal whole-mounts, peak cone density ranged from 11,600-14,200/cones mm(2). The 11- to 12-mm-wide peak region centered roughly on the optic disc, although foveal counts remain to be completed. Density decreased symmetrically to a far peripheral band of 4,200-7, 000/cones mm(2). In contrast, S cone density was very low in central retina (0-300/mm(2)), rose symmetrically with eccentricity, and peaked at 1,100-1,600/mm(2) in a 2- to 3-mm-wide zone in the far periphery. In this zone, S cones were 9-14% of all cones. L/M cones were regularly spaced, whereas S cones showed no regular distribution pattern. Although the functional characteristics of the tarsier S and L/M cone systems are yet to be determined, tarsier cone proteins and distribution have some similarities to both New and Old World monkey retinas.


Asunto(s)
Adaptación a la Oscuridad/fisiología , Luz , Retina/citología , Células Fotorreceptoras Retinianas Conos/citología , Opsinas de Bastones/metabolismo , Tarsiidae/anatomía & histología , Animales , Recuento de Células , Femenino , Masculino , Retina/fisiología , Células Fotorreceptoras Retinianas Conos/fisiología , Tarsiidae/fisiología
12.
Int J Radiat Oncol Biol Phys ; 28(3): 641-7, 1994 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-8113107

RESUMEN

PURPOSE: This study was carried out to determine whether chronic low dose radiation can act alone or in synergy with restricted diet in down-regulating spontaneously occurring mammary tumor in tumor-susceptible female C3H/He mice and whether immune cells are involved. METHODS AND MATERIALS: At 7 months of age, one-half of the experimental mice were maintained on an ad lib diet, and the other half was adapted over a period of 1 month to a diet of 70% of the daily amount of food consumed by the ad lib-fed mice. The food of the restricted diet was enriched such that the vitamin and mineral intake was the same for both groups. Half of the mice in each group was then subjected to chronic low dose radiation (0.04 Gy per exposure from a 60Co source, 3 x-per-week for 4 weeks) and the other half was sham irradiated. The 70% calorically restricted diet was maintained throughout the study. RESULTS: Chronic low dose radiation alone was ineffective in down-regulating spontaneous mammary tumor, unlike caloric restriction. However, chronic low dose radiation when combined with caloric restriction promoted regression of mammary tumors, which were infiltrated with massive numbers of CD8+ T cells. These phenomena were not seen in mice subjected to caloric restriction alone. CONCLUSION: Combined chronic low dose radiation-caloric restriction appears to be a useful model for promoting spontaneous mammary tumor regression.


Asunto(s)
Ingestión de Energía/fisiología , Neoplasias Mamarias Experimentales/radioterapia , Animales , Regulación hacia Abajo , Femenino , Neoplasias Mamarias Experimentales/inmunología , Ratones , Ratones Endogámicos C3H , Modelos Biológicos , Dosis de Radiación , Inducción de Remisión
13.
Am J Med Genet ; 102(4): 383-6, 2001 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-11503168

RESUMEN

Smith-Lemli-Opitz syndrome (SLOS) is an inherited multiple malformation syndrome caused by enzymatic deficiency of 3beta-hydroxysterol-Delta(7)-reductase (DHCR7). SLOS is thought to be most common among European Caucasians, with an incidence of 1 in 20,000 to 1 in 30,000 births. To define the carrier rate and ethnic distribution of SLOS, we screened DNA samples from 2,978 unrelated individuals for the most common SLOS mutation (IVS8-1G-->C). Twenty-four heterozygotes of the IVS8-1G-->C mutation were detected in 2,978 individuals of European Caucasian and Black backgrounds. For European Caucasians, the carrier rate for SLOS may be as high as 1 in 30, suggesting an incidence of 1 in 1,700 to 1 in 13,400. This high number is supported by the recent observation of newborn and prenatal incidence of 1 in 22,000 in the Caucasian population. Ours is the first report of the IVS8-1G-->C mutation in persons of African ancestry. Published 2001 Wiley-Liss, Inc.


Asunto(s)
Frecuencia de los Genes/genética , Mutación/genética , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH , Oxidorreductasas/genética , Síndrome de Smith-Lemli-Opitz/enzimología , Síndrome de Smith-Lemli-Opitz/genética , Europa (Continente)/epidemiología , Europa (Continente)/etnología , Tamización de Portadores Genéticos , Pruebas Genéticas , Humanos , Síndrome de Smith-Lemli-Opitz/etnología
14.
Radiat Res ; 139(1): 47-52, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8016307

RESUMEN

The proliferative response to mitogenic stimulation by splenocytes can be augmented by exposing mice to whole-body, chronic, intermittent low doses of ionizing radiation, referred to here as low-dose irradiation. The purpose of this study was to identify the cell(s) in the spleen which is responsive to the proliferation-augmenting effect of low-dose irradiation, i.e., the cellular target. C57BL/6 mice were subjected to low-dose irradiation (0.04 Gy/exposure/day, 5 consecutive days/week, 2 weeks) or to sham irradiation. Three days after the last exposure, spleens were removed, separated into cell fractions which were nonadherent and adherent to plastic surfaces and reconstituted in various combinations, and their proliferative responses to various mitogens were determined. Highly purified T cells were also used in place of the nonadherent cell fraction in the reconstitution studies. The target cells were shown to be T cells. The target T cells of low-dose-irradiated mice possessed elevated constitutive levels of HSP-70 mRNA and HSP-72, and they responded to T-cell receptor-specific anti-CD3 stimulation by producing more HSP-70 mRNA and HSP-72 and by proliferating more extensively than T cells of sham-irradiated mice.


Asunto(s)
Activación de Linfocitos/efectos de los fármacos , Linfocitos T/efectos de la radiación , Animales , Linfocitos B/inmunología , Linfocitos B/efectos de la radiación , Células Cultivadas , Concanavalina A , Relación Dosis-Respuesta en la Radiación , Expresión Génica/efectos de la radiación , Gliceraldehído-3-Fosfato Deshidrogenasas/biosíntesis , Proteínas de Choque Térmico/biosíntesis , Humanos , Lipopolisacáridos , Masculino , Ratones , Ratones Endogámicos C57BL , Fitohemaglutininas , ARN Mensajero/metabolismo , Valores de Referencia , Bazo/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo
15.
Science ; 250(4982): 836-8, 1990 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-17759976
16.
J Microbiol Methods ; 50(2): 215-23, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11997172

RESUMEN

Restriction fragment length polymorphism of rRNA operons (RFLP) and 16S-23S rRNA intergenic region (ISR) sequences of Bacillus subtilis subsp. subtilis, B. subtilis subsp. spizizenii, and B. atrophaeus were compared. ISR sequences of the B. subtilis subspecies were extremely similar (W23 versus 168 rrn H, J, G,W; 96.8%; rrn D, E; 98.4%; rrnB; 97.9%) and, therefore, not useful for their differentiation. However, RFLP of rRNA operons of the B. subtilis subspecies were distinct in terms of numbers and organization within the genome (e.g. the 168 sub-group generally contained 8.3- and 8.0-kb fragments absent in the W23 sub-group). The more distantly related B. atrophaeus was distinct from both B. subtilis subspecies in terms of ISR sequence and rRNA operon number and organization. RFLP of rRNA operons discriminates the two sub-groups of Bacillus subtilis that are indistinguishable by ISR sequence. However, ISR sequence defines the relatedness of B. subtilis to other species (e.g. B. atrophaeus) within the genus Bacillus.


Asunto(s)
Bacillus subtilis/clasificación , ADN Espaciador Ribosómico/análisis , Polimorfismo de Longitud del Fragmento de Restricción , Operón de ARNr/genética , Bacillus subtilis/genética , Técnicas de Tipificación Bacteriana , ARN Ribosómico 16S/genética , ARN Ribosómico 23S/genética , Ribotipificación
17.
Int J Radiat Biol ; 63(6): 775-83, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8100265

RESUMEN

The purpose of this study was to determine whether the enhanced proliferative activity of splenocytes induced by exposing mice to whole body, chronic, intermittent low doses of ionizing radiation is associated with an increase in the expression of stress protein genes. Mice were exposed to a gamma-irradiation protocol of 0, 0.04 or 0.10 Gy/day for 5 consequent days/week, for 4 weeks. Splenocytes were then assessed for their levels of heat shock protein (HSP) 70 mRNA, glyceraldehyde 3-phosphate dehydrogenase (GAPD) mRNA, HSC70 (a constitutively-expressed isoform of HSP70) and HSP72 (an inducible isoform of HSP70), before and 1 day after mitogenic stimulation. Splenocytes from mice exposed to 0.04 Gy/exposure contained elevated constitutive levels of HSP70 mRNA, HSC70 and HSP72. These splenocytes responded to T, but not B, cell mitogens by further increasing their levels of HSP70 mRNA, HSC70 and HSP72 and by mounting a heightened proliferative response. However, an exposure of 0.10 Gy was ineffective. Thus, the constitutive levels of HSP70 mRNA, HSC70 and HSP72 and the mitogen-stimulated levels of HSC70 and HSP72 of splenocytes from mice exposed to 0.10 Gy/exposure were comparable with those of sham-irradiated mice. Moreover, their proliferative activity in response to mitogenic stimulation was also comparable with that of splenocytes from sham-irradiated mice.


Asunto(s)
Proteínas Portadoras/análisis , Proteínas HSP70 de Choque Térmico , Proteínas de Choque Térmico/análisis , ARN Mensajero/análisis , Bazo/efectos de la radiación , Animales , Proteínas del Choque Térmico HSC70 , Masculino , Ratones , Ratones Endogámicos C57BL , Dosis de Radiación , Bazo/química , Bazo/citología , Factores de Tiempo , Irradiación Corporal Total
20.
Acta Psychiatr Scand ; 116(3): 165-73, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17655557

RESUMEN

OBJECTIVE: To investigate whether the recent repetitive transcranial magnetic stimulation (rTMS) studies on depression using new parameters of stimulation have shown improved clinical results. METHOD: We performed a systematic review and a meta-analysis of the rTMS studies on depression published in the past 12 months comparing these results with an earlier meta-analysis that analyzed the results of the initial rTMS studies on depression. RESULTS: Using our inclusion criteria, we selected the meta-analysis of Martin [Br J Psychiatry (2003) Vol. 182, 480-491] that included 13 studies (324 patients) and five studies for the recent meta-analysis (274 patients). The pooled effect size (standardized mean difference between pretreatment vs. post-treatment) from the random effects model was -0.76 (95% confidence interval, CI, -1.01 to -0.51). This result was significantly larger than that of the earlier meta-analysis (-0.35, 95% CI -0.66 to -0.04). CONCLUSION: Our findings suggest that recent rTMS clinical trials have shown larger antidepressant effects when compared with the earlier studies.


Asunto(s)
Trastorno Depresivo/terapia , Estimulación Magnética Transcraneal , Trastorno Depresivo/diagnóstico , Trastorno Depresivo/fisiopatología , Trastorno Depresivo/psicología , Dominancia Cerebral/fisiología , Humanos , Corteza Prefrontal/fisiopatología , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA