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1.
Acta Virol ; 59(4): 429-33, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26666193

RESUMEN

Sharka disease is one of the most devastating plant epidemics of Prunus species, caused by plum pox virus (PPV). The viral infection affects the fruits by weight-loss and degradation of quality properties. Breeding of resistant rootstocks and cultivars is one of the most effective disease control methods. PPV determines the peach production all over the world. On the world's fruit production list peach is in the sixth, in the Mediterranean region in the fourth place. In this study new data were shown about PPV susceptibility of commonly used rootstock-scion combinations from Hungary. Reverse transcription PCR (RT-PCR) analysis was conducted on the samples from a commercial orchard; the results were evaluated by chi-square test and binary logistic regression. Four rootstock ('GF677', 'PeMa', 'Cadaman' and almond seedlings) and three scion cultivars (Prunus persicae 'Michelini', 'Babygold 6' and 'Cresthaven') were included in this experiment. The rootstocks did not show any significant differences in regard to the resistance of the virus infection (40-50%), but in case of scions, strong significant relations were observed. In case of the combinations there were results in both directions; tolerant and susceptible combinations were observed as well.


Asunto(s)
Hibridación Genética , Enfermedades de las Plantas/virología , Virus Eruptivo de la Ciruela/fisiología , Prunus persica/inmunología , Hungría , Enfermedades de las Plantas/genética , Enfermedades de las Plantas/inmunología , Prunus/genética , Prunus/inmunología , Prunus persica/genética , Prunus persica/virología
2.
Eur J Neurol ; 18(1): 69-77, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20561039

RESUMEN

BACKGROUND: most disease-modifying therapies (DMTs) for multiple sclerosis (MS) are self-injectable medications that must be taken on an ongoing basis to reduce disease activity. Thus, adherence to therapy becomes an important challenge that must be addressed to maximize benefits of therapy. This study evaluated rates of adherence to prescribed treatment and explored factors affecting adherence amongst patients with relapsing-remitting MS. METHODS: this was an observational, multicenter, multinational, phase 4 study. Patients and physicians received paper questionnaires regarding adherence to DMTs approved at the time of the study, including intramuscular interferon beta-1a (IFNß-1a), subcutaneous IFNß-1a, IFNß-1b, and glatiramer acetate. Quality of life and cognition data also were collected. Multivariate analysis was conducted to identify factors associated with adherence to long-term DMTs. RESULTS: two thousand six hundred and forty-eight patients were studied, revealing an average treatment duration of 31 months. Seventy-five percent of patients (n = 1923) were adherent to therapy. The most common reasons for non-adherence were forgetting to administer the injection (50.2%) and other injection-related reasons (32.0%). Adherent patients reported better quality of life (P < 0.05) and fewer neuropsychological issues (P < 0.001) than non-adherent patients. Adherent patients had significantly shorter duration of disease (P < 0.001) and shorter duration of therapy (P = 0.005) than non-adherent patients. Women were more likely than men to adhere to treatment. CONCLUSION: identifying factors that affect adherence to prescribed treatments is the first step in improving adherence of patients with MS to therapy, thereby helping maximize the benefits of long-term DMTs.


Asunto(s)
Interferón beta/uso terapéutico , Cumplimiento de la Medicación , Esclerosis Múltiple Recurrente-Remitente/terapia , Péptidos/uso terapéutico , Femenino , Acetato de Glatiramer , Humanos , Factores Inmunológicos/uso terapéutico , Masculino , Calidad de Vida , Encuestas y Cuestionarios
3.
J Endocrinol ; 122(1): 361-70, 1989 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2549152

RESUMEN

Initial 45Ca uptake was measured in isolated rat glomerulosa cells. A small reduction in membrane potential produced by increasing the K+ concentration from 2 to 3.6 mmol/l stimulated 45Ca uptake by about 35%, while a bigger depolarization induced by 18.5 mmol K+/l increased the uptake by about 100%. Since Ca2+ influx was already activated at a calculated membrane potential below -70 mV, and was found to be sensitive to the dihydropyridine antagonist nifedipine (1 mumol/l), but insensitive to nickel ions (100 mumol/l), it does not meet the criteria established for T- or L-type voltage-dependent Ca2+ channels. Exposure of glomerulosa cells to angiotensin II (AII) for 10 min also enhanced the rate of 45Ca influx. The effect of AII was not sensitive to 1 mumol nifedipine/l, but was strongly inhibited by 5-(N-4-chlorobenzyl)-N-(2',4'-dimethyl)benzamil (CBDMB, 30 mumol/l), an inhibitor of the Na+/Ca2+ antiporter. These observations suggest that during the sustained phase of stimulation with AII, a CBDMB-sensitive mechanism, rather than dihydropyridine-sensitive calcium channels, is involved in Ca2+ uptake in rat glomerulosa cells. The bulk Ca2+ influx did not correlate with aldosterone production; however, the maintained activity of different Ca2+ entry mechanisms seems to be essential for AII-induced aldosterone production.


Asunto(s)
Angiotensina II/farmacología , Calcio/metabolismo , Potasio/farmacología , Zona Glomerular/metabolismo , Aldosterona/metabolismo , Amilorida/análogos & derivados , Amilorida/farmacología , Animales , Canales de Calcio/efectos de los fármacos , Proteínas Portadoras/antagonistas & inhibidores , Proteínas Portadoras/metabolismo , Células Cultivadas , Potenciales de la Membrana , Proteínas de la Membrana/antagonistas & inhibidores , Proteínas de la Membrana/metabolismo , Ratas , Ratas Endogámicas , Sodio/metabolismo , Intercambiador de Sodio-Calcio , Zona Glomerular/efectos de los fármacos
4.
J Dent Res ; 74(8): 1501-6, 1995 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7560406

RESUMEN

Many authors have studied the hemodynamics of the dental pulp; however, there are scarcely any data regarding the involvement of the L-arginine/nitric oxide pathway in the regulatory mechanism. Thus, we have examined the physiological effects of (1) NG-nitro-L-arginine as an inhibitor of nitric oxide synthesis and (2) the nitric oxide donor 3-morpholinosydnonimine on blood flow and vascular resistance in the canines of anesthetized cats to study the potential involvement of nitric oxide in the regulation of dental vascular homeostasis. Mean arterial blood pressure, heart rate, blood gases, pH, cardiac output, and tissue blood flow were determined prior to and 15 min after i.v. administration of either NG-nitro-L-arginine (30 mg/kg, n = 9) or 3-morpholinosydnonimine (1 mg/kg, n = 7). Blood flow was measured by radioactive-labeled microspheres. There were no significant differences in baseline parameters between the two groups of cats. The dental pulp blood flow decreased to 53 +/- 13% (p < 0.01) of the control level after NG-nitro-L-arginine administration, while it decreased only slightly (to 82 +/- 12%) after 3-morpholinosydnonimine administration. The dental pulp's vascular resistance increased to 367 +/- 69% (p < 0.01) of the control level after NG-nitro-L-arginine, while it decreased to 73 +/- 10% (p < 0.05) of control after 3-morpholinosydnonimine. We found that the L-arginine/nitric oxide pathway plays an important role in the regulation of pulpal blood circulation.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Pulpa Dental/irrigación sanguínea , Óxido Nítrico/fisiología , Animales , Arginina/análogos & derivados , Arginina/farmacología , Arginina/fisiología , Presión Sanguínea/efectos de los fármacos , Gasto Cardíaco/efectos de los fármacos , Gatos , Diente Canino , Inhibidores Enzimáticos/farmacología , Frecuencia Cardíaca/efectos de los fármacos , Homeostasis , Masculino , Molsidomina/análogos & derivados , Molsidomina/farmacología , NG-Nitroarginina Metil Éster , Óxido Nítrico/antagonistas & inhibidores , Óxido Nítrico Sintasa/antagonistas & inhibidores , Oxígeno/sangre , Flujo Sanguíneo Regional , Resistencia Vascular/efectos de los fármacos , Vasodilatadores/farmacología
5.
Plant Cell Rep ; 20(2): 169-174, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30759905

RESUMEN

Catalase (CAT) and superoxide dismutase (SOD) activity profiles were examined by native polyacrylamide gel electrophoresis in different tissues of seedlings and microcuttings of oak (Quercus robur L.) initiated from crown material (NL100A) and from basal epicormic shoots (NL100R), which differ in rooting ability. Two CAT isoforms were differentially active in seedlings and microcuttings; in particular, CAT-2 was activated in the basal callus of rooted microshoots. SOD isoenzymes, Mn-SOD and at least four Cu/Zn-SODs were found to be present, with Mn-SODs particularly active in microcuttings. No differences were found between the electrophoretic profiles of the two lines despite their different ontogenetic origin. The strong activity of CAT-2 in rooted microshoots indicates that this isoform is a protein specifically related to rooting.

6.
Arch Oral Biol ; 41(7): 699-704, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9015572

RESUMEN

The aim was to examine whether (1) blood flow and vascular resistance are altered in response to exogenous nitric oxide and (2) whether endogenous synthesis of nitric oxide participates in the haemodynamic regulation of the submandibular, parotid and pancreatic glands. Experiments were performed on anaesthetized, artificially ventilated cats. Mean arterial blood pressure, heart rate, blood gases, cardiac output and tissue blood flow were determined before and 15 min after intravenous administration of either the nitric oxide donor SIN-1 (3-morpholinosydnonimine, 1 mg/kg, n = 10) or the competitive nitric oxide synthase inhibitor NOLA (NG-nitro-L-arginine, 30 mg/kg, n = 9) blood flow was measured by a radioactive-labelled microsphere method. In the SIN-1 group, in spite of a serious decrease in mean arterial blood pressure (p < 0.001), the blood flow in the glands remained unchanged. The vascular resistance decreased after SIN-1 in the submandibular and pancreatic glands (p < 0.001 and p < 0.05, respectively), and was slightly reduced in the parotid. The NOLA increased mean arterial blood pressure (p < 0.01) and reduced the blood flow in the submandibular and pancreatic glands (p < 0.01 and p < 0.001, respectively), but the decrease in the parotid was not significant. Vascular resistance increased after NOLA in all three glands (p < 0.05, p < 0.001 and p < 0.05). These findings suggest that basal nitric oxide production in these exocrine glands is sufficient to modulate vascular resistance. Moreover, the release of endogenous NO from the nerves and/or endothelium is probably involved in the regulation of vascular tone. The nitric oxide-dependent component of blood-flow regulation, however, seems to be less pronounced in the parotid gland.


Asunto(s)
Glándulas Exocrinas/irrigación sanguínea , Hemodinámica/efectos de los fármacos , Óxido Nítrico Sintasa/metabolismo , Óxido Nítrico/fisiología , Animales , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Gatos , Endotelio Vascular/enzimología , Endotelio Vascular/inervación , Inhibidores Enzimáticos/farmacología , Glándulas Exocrinas/enzimología , Masculino , Molsidomina/análogos & derivados , Molsidomina/farmacología , Fibras Nerviosas/metabolismo , Óxido Nítrico/biosíntesis , Óxido Nítrico/farmacología , Óxido Nítrico Sintasa/análisis , Óxido Nítrico Sintasa/antagonistas & inhibidores , Nitroarginina/farmacología , Páncreas/irrigación sanguínea , Páncreas/enzimología , Glándula Parótida/irrigación sanguínea , Glándula Parótida/enzimología , Flujo Sanguíneo Regional/efectos de los fármacos , Glándula Submandibular/irrigación sanguínea , Glándula Submandibular/enzimología , Resistencia Vascular/efectos de los fármacos , Vasodilatadores/farmacología
7.
Ann N Y Acad Sci ; 738: 348-68, 1994 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-7530422
9.
Fiziol Zh (1994) ; 55(6): 41-7, 2009.
Artículo en Ucraniano | MEDLINE | ID: mdl-20201387

RESUMEN

Microencapsulated human parathyroid tissue preserves the viability and high ability to secrete parathormone in long-term culture that indicates on perspective to further study the efficiency of using this tissue in the presence of compensated hypofunctional state of parathyroid system in experimental animals.


Asunto(s)
Técnicas de Cultivo de Órganos/métodos , Glándulas Paratiroides , Hormona Paratiroidea/metabolismo , Alginatos , Medios de Cultivo , Humanos , Glándulas Paratiroides/anatomía & histología , Glándulas Paratiroides/metabolismo , Glándulas Paratiroides/fisiología , Factores de Tiempo
10.
Artículo en Inglés | MEDLINE | ID: mdl-3496294

RESUMEN

The response of mouse embryos to different concentrations of cadmium or mercury with or without low LET radiation was measured in terms of gross morphological anomalies and cellular changes. Single doses of the heavy metals (2 mg/kg body weight) were injected i.p. on day 8 of gestation 30 min before whole-body irradiation. Combined exposures to CdCl2 and X-rays led to a significant reduction in the rate of exencephaly compared with the high frequency after cadmium alone. The hypothesis that metallothionein, a sulphur-rich and metal-binding protein, may be responsible for the antagonism observed could not be confirmed. Mercuric chloride alone induced a low rate of exencephaly and the data on combined treatment suggest additivity with 0.5 and 1.0 Gy X-rays. Regarding cellular criteria, cell death in the eye anlage on day 9 of gestation was significantly suppressed after 0.5 Gy and especially after CdCl2 plus 0.5 Gy compared to cadmium alone. It is assumed that the reduction of cell lethality is correlated with the low occurrence of exencephaly. Concerning the proliferation of neuroblasts, cadmium stimulated the mitotic activity whereas X-rays depressed the proliferation capacity. After the combined treatment a distinct antimitotic effect was established.


Asunto(s)
Anomalías Inducidas por Medicamentos , Anomalías Inducidas por Radiación , Cadmio/toxicidad , Mercurio/toxicidad , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Femenino , Ratones , Embarazo
11.
Artículo en Húngaro | MEDLINE | ID: mdl-36506

RESUMEN

Authors analysing 31 case histories of talus fractures and following the results in 22 cases over a period of 3--12 years support the general view, that the healing of such injuries is satisfactory but partial or even total necrosis may occur. They emphasize the importance of X-ray investigation and occasional phlebography in order to clear up the state of circulation in the bone. Weight bearing should be decided in accordance with these examinations.


Asunto(s)
Traumatismos del Tobillo , Luxaciones Articulares/diagnóstico por imagen , Astrágalo/lesiones , Adolescente , Adulto , Anciano , Articulación del Tobillo/diagnóstico por imagen , Huesos/irrigación sanguínea , Femenino , Humanos , Masculino , Persona de Mediana Edad , Necrosis/prevención & control , Flebografía , Astrágalo/diagnóstico por imagen
12.
Artículo en Húngaro | MEDLINE | ID: mdl-36508

RESUMEN

The clinical appearance of primary spleen rupture with latent bleeding is dealt with. Diagnostic difficulties, possible methods of examination and their evaluation are demonstrated. Selected characteristic cases from among their material are introduced.


Asunto(s)
Rotura del Bazo/diagnóstico , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diálisis Peritoneal , Esplenectomía , Rotura del Bazo/etiología , Rotura del Bazo/cirugía , Traumatismos Torácicos/complicaciones
13.
Artículo en Húngaro | MEDLINE | ID: mdl-6114226

RESUMEN

The results of the analysis of 52 central talar fractures and 37 follow-up cases in the 10 year material of the National Institute of Trauma are reported here. They point to the fact, that osteoarthritis can be avoided by appropriate treatment. Two aetiological factors in arthritis are the residual joint surface incongruence and the damage to the blood supply. Immediate, exact reduction and retention, even operatively if necessary and the delay of weight bearing until the restoration of blood supply and the bony architecture are recommended as preventive measures. If doubt arises on the diagnosis of damaged blood supply, intraosseous venography is recommended.


Asunto(s)
Fracturas Óseas/cirugía , Astrágalo/lesiones , Adolescente , Adulto , Anciano , Niño , Femenino , Fijación Interna de Fracturas , Fracturas Óseas/diagnóstico por imagen , Humanos , Luxaciones Articulares/diagnóstico por imagen , Luxaciones Articulares/cirugía , Masculino , Persona de Mediana Edad , Radiografía , Astrágalo/diagnóstico por imagen , Astrágalo/cirugía
14.
Radiat Environ Biophys ; 28(1): 1-12, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2919222

RESUMEN

The peroxidase-coupled Dolichos biflorus agglutinin (DBA) served as a marker for cell surface alterations in embryonic mouse tissues exposed to low-dose radiation during the early organogenesis (day 9 post conception). In unirradiated embryos, DBA bound selectively to various organ primordia, depending on their differentiation state. The auditory vesicles and the developing blood vessels were the only tissues staining strongly with the lectin. The vascular endothelia also showed the highest radiosensitivity, expressed by the maximal reaction already at 12.5 cGy. Marked surface changes as well were registered in the basal part of the Rathke's pocket and in the roof of the diencephalon. After exposure to 25 cGy, a transient amplification of the reaction as compared with 12.5 cGy occurred firstly in the Rathke's pocket, then in the infundibulum and in auditory vesicles. The most distinct effects were achieved with 50 cGy. Remarkable is the prompt rise of the DBA-affinity in a narrow area of the myelencephalon, and subsequently also in the roof of the diencephalon. Furthermore, the infundibulum and the Rathke's pocket, both anlagen of the pituitary gland, bound heavily DBA during the entire examination period of 24 h. The present study demonstrated the outstanding suitability of the Dolichos biflorus agglutinin for histochemical detection of subtle cellular alterations by small radiation doses.


Asunto(s)
Membrana Celular/efectos de la radiación , Desarrollo Embrionario y Fetal/efectos de la radiación , Lectinas , Lectinas de Plantas , Animales , Membrana Celular/análisis , Relación Dosis-Respuesta en la Radiación , Histocitoquímica , Ratones , Ratones Endogámicos
15.
Artículo en Inglés | MEDLINE | ID: mdl-3497893

RESUMEN

The modification of radiation damage by various concentrations of the oncolytic drug vindesine was studied macroscopically, using mouse embryos during the early organogenesis (days eight and nine of gestation) as the test system. The analysis at term showed that the developmental toxicity of vindesine depends on the dosage and the time of administration. In the lower dose-range (0.25 and 0.35 mg/kg), the only reaction was growth retardation, whereas higher concentrations (0.5 and 1.0 mg/kg) led mainly to an early resorption of implants. The more differentiated stage (day nine) exhibited a much higher sensitivity to vindesine than the embryo on day eight. Conversely, the harmful action of 0.9 Gy X-rays was restricted to the earlier period of organogenesis. The incidence of abnormalities after irradiation on day eight was 4.5 times higher than the one following exposure on day nine. The combined exposures showed a radiosensitizing capacity of the drug with respect to the teratogenic response on day eight only. The pretreatment with 0.25 mg/kg vindesine potentiated the radiation-induced malformation rate by a factor of 1.7, and the one with 0.35 mg/kg vindesine by a factor of 2.4.


Asunto(s)
Anomalías Inducidas por Medicamentos , Anomalías Inducidas por Radiación , Antineoplásicos/toxicidad , Desarrollo Embrionario y Fetal/efectos de la radiación , Vindesina/toxicidad , Animales , Antineoplásicos/administración & dosificación , Desarrollo Embrionario y Fetal/efectos de los fármacos , Femenino , Ratones , Embarazo , Vindesina/administración & dosificación
16.
Injury ; 13(4): 317-23, 1982 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7061141

RESUMEN

Fracture-dislocations of the talus are often followed by avascular necrosis. In these cases weight bearing must be forbidden in order to prevent collapse of the talus. Experience with intraosseous phlebography in 31 cases and a 2- to 6-year follow-up in 25 of them showed that this is a useful diagnostic procedure in the assessment of the talar blood supply, and an important aid in deciding the necessary period of relief from weight bearing as well as giving a prognosis.


Asunto(s)
Fracturas Óseas/diagnóstico por imagen , Luxaciones Articulares/diagnóstico por imagen , Flebografía/métodos , Astrágalo/lesiones , Adulto , Femenino , Humanos , Masculino , Pronóstico , Astrágalo/irrigación sanguínea , Astrágalo/diagnóstico por imagen
17.
Experientia ; 39(1): 95-6, 1983 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-6825787

RESUMEN

Mouse embryos on day 9 of gestation were exposed in utero to 90 rad X-rays. At different time intervals after treatment the eye primordia were examined for cell death. The irradiation caused an altered necrosis pattern compared with day 8, and massive cell killing during a limited time period. The rapid recovery from the pronounced damage points to a high restitution efficiency of the involved tissue.


Asunto(s)
Embrión de Mamíferos/efectos de la radiación , Ojo/embriología , Animales , Supervivencia Celular , Ojo/efectos de la radiación , Femenino , Edad Gestacional , Cinética , Ratones , Fenómenos Fisiológicos Oculares , Embarazo , Regeneración
18.
Am J Physiol ; 254(6 Pt 1): C744-50, 1988 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2837093

RESUMEN

Sodium uptake by rat adrenal glomerulosa cells was stimulated by intracellular acidosis evoked by Na+-propionate. This process was inhibited by 5-(N,N-hexamethylene) amiloride (HMA), a known inhibitor of the Na+-H+ exchange. These experiments demonstrate the existence of the Na+-H+ exchange in glomerulosa cells. Although amiloride inhibited the angiotensin II- and adrenocorticotropic hormone (ACTH)-induced aldosterone response, HMA, a more specific inhibitor of Na+-H+ exchange, failed to do that. 45Ca2+ influx and efflux were dependent on intra- and extracellular Na+ concentrations. Amiloride analogues, known to inhibit Na+-Ca2+ exchange, reduced basal 45Ca influx. Although we could not reveal the activation of Na+-Ca2+ exchange by angiotensin II, inhibitors of Na+-Ca2+ exchange also inhibited the angiotensin- and ACTH-induced aldosterone response of glomerulosa cells. Our results suggest that Na+-Ca2+ exchange supports the maintenance of basal Ca2+ level in the cytoplasma of glomerulosa cells, and amiloride derivatives inhibit aldosterone production by reducing Ca2+ level below resting values.


Asunto(s)
Glándulas Suprarrenales/metabolismo , Aldosterona/biosíntesis , Calcio/metabolismo , Hidrógeno/metabolismo , Sodio/metabolismo , Amilorida/análogos & derivados , Amilorida/farmacología , Angiotensina II/farmacología , Animales , Proteínas Portadoras/metabolismo , Células Cultivadas , Proteínas de la Membrana/metabolismo , Ratas , Ratas Endogámicas , Intercambiador de Sodio-Calcio , Intercambiadores de Sodio-Hidrógeno
19.
Am J Physiol ; 258(4 Pt 1): E555-61, 1990 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2333957

RESUMEN

Angiotensin-induced aldosterone production by superfused adrenal glomerulosa cells was potentiated by Ni2+ (0.1 mM), added either at the onset of stimulation with angiotensin II or 1 h later. Nickel did not influence the effect of adrenocorticotropic hormone or potassium on aldosterone production. Nickel failed to modify angiotensin-induced changes in phospholipid metabolism or the formation of inositol phosphates and slightly reduced the enhancement of 45Ca influx. Uptake of Ni2+ into glomerulosa cells was increased by depolarization in a dihydropyridine-insensitive manner. Because nickel selectively potentiates the sustained phase of the response to a calcium-mobilizing hormone, it may serve as a suitable tool in elucidating the signal transduction process during the sustained phase of stimulation.


Asunto(s)
Aldosterona/biosíntesis , Angiotensina II/farmacología , Níquel/farmacología , Zona Glomerular/metabolismo , Animales , Transporte Biológico Activo/efectos de los fármacos , Calcio/metabolismo , Cobalto/farmacología , Femenino , Técnicas In Vitro , Fosfatos de Inositol/metabolismo , Cinética , Masculino , Níquel/metabolismo , Ratas , Ratas Endogámicas , Zona Glomerular/efectos de los fármacos
20.
Cardiologia ; 43(3): 287-93, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9611857

RESUMEN

The morphology of the first spontaneous post-pacing P wave was assessed in 106 patients who underwent electrophysiological study for various arrhythmias. An overall number of 589 atrial pacing sessions, from 60-200 b/min, were analyzed (mean 5.55 +/- 1.3 session per patient). After cessation of 138 (23.42%) of them, spontaneous post-pacing P wave arose from extrasinus foci. Nonsinus spontaneous post-pacing P waves were recorded after 1 or more pacing rates (from 1 to 7) in 58 patients (54.7%, Group 1). In the remaining 48 patients the spontaneous post-pacing P waves were sinus after all pacing sessions (45.3%, Group 2). Sinus node disease (SND) was present in 32.7% of Group 1 patients and in 2% of Group 2 (p = 0.002). Spontaneous post-pacing P wave of extrasinus origin was recorded in 19/20 of SND patients (95%) compared to 39/86 of patients with normal sinus function (45.34%, p < 0.001). SND patients had a greater number of pacing sessions resulting in nonsinus spontaneous post-pacing P waves. Pacing rate associated with nonsinus spontaneous post-pacing P waves was lower in SND patients compared to patients with normal sinus node function. In the SND group, nonsinus spontaneous post-pacing P waves were recorded beyond the first spontaneous one in 9 patients compared to only 1 in patients with normal sinus node function (p < 0.005). Extrasinusal first spontaneous post-pacing P waves at a pacing rate of 140 b/min had the highest sensitivity (75%). Increasing of pacing rate from 60 to 140 b/min was associated with progressive arousal of secondary foci with highest value of 36.8% in pacing rate of 140 b/min. Further increase of pacing rate resulted in a slight reduction of spontaneous post-pacing firing from secondary foci. Atropine was administered in 12 Group 1 patients and abolished all measurable morphological changes of spontaneous post-pacing P waves compared to pre-pacing. Autonomic blockade was performed in 14 Group 1 patients and 16 Group 2 patients. In 35.7% of Group 1 patients autonomic blockade abolished the appearance of nonsinus spontaneous post-pacing P waves, while in the remaining patients increased the lowest pacing rate resulting in nonsinus spontaneous post-pacing P waves. In 12.5% Group 2 patients autonomic blockade resulted in nonsinus spontaneous post-pacing P waves after cessation of atrial pacing. In conclusion, the extrasinus spontaneous rise of atrial impulse is a very frequent phenomenon after atrial pacing especially in patients with SND. Pacing rate has different quantitative effects on sinus and secondary atrial pacemakers. Secondary pacemakers are less under autonomic control compared to sinus node.


Asunto(s)
Bloqueo Nervioso Autónomo , Estimulación Cardíaca Artificial , Electrocardiografía , Nodo Sinoatrial/fisiología , Adulto , Anciano , Antiarrítmicos/farmacología , Arritmias Cardíacas/fisiopatología , Atropina/farmacología , Sistema Nervioso Autónomo/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad , Síndrome del Seno Enfermo/fisiopatología , Factores de Tiempo
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