Type of electrical stimulation influences diaphragm response to adrenoceptor and calcium channel modulators: the role of extracellular and intracellular calcium events.

The influence of direct single pulse and subtetanic electrical stimulation (ES) on isolated rat hemidiaphragm response to adrenoceptor antagonists and calcium channel blockers was investigated. Muscle contractility was stimulated by cumulative micromolar noradrenaline. Noradrenaline effects on developed tension (Td) in the presence of various alpha- and beta-adrenoceptor antagonists (e.g., prazosin and ICI 118551) were qualitatively different during different types of ES. Also, intact L-voltage calcium channels were necessary for noradrenaline-induced potentiation of Td during both types of ES, while the balance between ryanodine receptors- and inositol triphosphate (IP3)-related calcium events in the muscle was influenced by the pattern of the ES.

NG-nitro-L-arginine methyl ester-induced potentiaton of the effect of aminophylline on rat diaphragm: the role of extracellular calcium.

The role of extracellular calcium in the interaction between intracellular cAMP and nitric oxide (NO)/cGMP on the contractility of rat diaphragm pretreated with cumulative concentrations of aminophylline (0.36 - 3.60 mM) was investigated. In a Ca2+-free medium, NG-nitro-L-arginine methyl ester (L-NAME) (1 and 3 mM) depressed tension developed (Td) and also aminophylline-induced potentiation of Td in a concentration-dependent manner. Verapamil (2.5 microM) or nicardipine (20 microM) significantly antagonized the potentiating effect of L-NAME on Td in a calcium-containing medium. However, in the presence of verapamil or nicardipine, L-NAME still produced statistically significant potentiation of the cumulative concentrations of aminophylline (0.36 - 3.60 mM), given in the second series.

[Clinical course and prognosis in hypoxic-ischemic encephalopathy]. / Klinicki tok i prognoza hipoksijsko-ishemijske encefalopatije.

BACKGROUND: Establishing the value of neurological examination, and additional diagnostic methods (ultrasonography and magnetic resonance imaging of the brain) in the diagnosis and prognosis of hypoxic-ischemic encephalopathy and its treatment, tracking the clinical course, and making the prognosis of neurological development in newborn infants with hypoxic-ischemic encephalopathy. METHODS: The group of 40 term newborn infants with suspected intrauterine asphyxia was examined. All the infants were prospectively followed until the 3rd year of age at the Clinic for Neurology and Psychiatry for Children and Youth in order to estimate their neurological development and to diagnose the occurrence of persistent neurological disorders. All the infants were analyzed by their gestational age and Apgar score in the 1st and the 5th minute of life. They were all examined neurologically and by ultrasonography in the first week of life and, repeatedly, at the age of 1, 3, 6, 9, 12, 18, as well as in the 24th month of life. They were treated by the standard methods for this disease. Finally, all the infants were examined neurologically and by magnetic resonance imaging of the brain in their 3rd year of age. On the basis of neurological finding infants were divided into 3 groups: infants with normal neurological finding, infants with mild neurological symptomatology, and infants with severe neurological disorders. RESULTS: It was shown that neurological finding, ultrasonography and magnetic resonance imaging of the brain positively correlated with the later neurological development of the infants with hypoxic-ischemic encephalopathy. CONCLUSION: Only the combined use of these techniques had full diagnostic and prognostic significance, emphasizing that the integrative approach was very important in the diagnosis of brain lesions in infants.