Preparation and structure of the system (Na1−xLax) (Nb1−(2x_3)Mg2x_3)O3 with x = 0.51, 0.50, 0.435 and 0.4275

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

Several parameters of the state of the nervous, immune and endocrine systems in newborn rats exposed to irradiation during the preimplantation period of embryogenesis]

About a decade ago the introduction of predictive testing for Huntington's disease (HD) was an important milestone in medical history. The aim of the present paper concerning predictive DNA-testing for HD is fourfold. First of all it describes the professional challenge of elaborating an adequate test protocol and of permanently using a multidisciplinary approach to deal with predictive test requests. Secondly the paper is aimed at unraveling the factors that play a part in uptake and decision making regarding predictive testing. Hereby the Health Belief Model is used as a framework for understanding differences between tested and untested persons. Thirdly the impact of the test result on psychological well-being is reviewed. Finally this paper assesses the utilisation of prenatal diagnosis after predictive testing for HD and reflects on the psychological and ethical implications of different types of prenatal tests, including preimplantation genetic diagnosis.     

Genetic heterogeneity of adrenocorticotropin (ACTH) resistance syndromes: identification of a novel mutation of the ACTH receptor gene in hereditary glucocorticoid deficiency

Hereditary primary adrenal insufficiency syndromes due to ACTH resistance include hereditary glucocorticoid deficiency (HGD) and Allgrove's syndrome (AS). Patients with both conditions present in childhood with failure to thrive, weakness, and fatigue or adrenal crisis; patients with AS in addition have alacrima and achalasia (triple A syndrome). We studied four kindreds with HGD and four kindreds with AS for abnormalities of the ACTH receptor (ACTHR) gene. The ACTHR coding sequence in all AS kindreds and two HGD kindreds was normal. Analysis of the ACTHR gene of the proband in one of the HGD kindreds showed him to be homozygous for the previously described G221T transition causing a Ser74Ile substitution of the protein, which has been shown to inactivate the ACTHR in signal transduction. The proband in another HGD kindred was found to be a compound heterozygote with the G221T transition in one allele and a novel C818A transition in the other allele of ACTHR. The C818A transition caused the substitution of the highly conserved Pro273 by His in the receptor protein. In vitro expression of the mutated ACTHR in mouse melanoma M3 cells showed that at a medium ACTH concentration of 3 nM, cells transfected with the wild-type ACTHR produced twofold and threefold, respectively, of the amount of intracellular cAMP when compared to cells transfected with the ACTHR carrying the Pro273His and the Ser74Ile mutation, respectively, confirming that HGD in this kindred is caused by loss-of-function mutations of the ACTHR. These results showed that the genetic cause of the ACTH-resistant syndromes is heterogeneous.     

The effect of dexamethasone on the reactions of the blood system in inflammation

On the model of carrageenan-induced acute aseptic peritonitis in rats it is shown that under influence of dexamethasone granulomonocytopoiesis, efflux of leukocytes to blood and their accumulation in inflammatory focus are increased and earlier completion of leukocytic reaction is observed and that the antiinflammatory effect of dexamethasone is mainly realized by the way of increasing of defence-adaptative blood system's reactions.     

Pattern generator for repetitive avian vocalization: preliminary localization and functional characterization

Electrical stimulation of the midbrain call areas was used to drive medullary neurons. Their activity was recorded with fine (25 mum) wire electrodes that allowed the nearer ones to be resolved as units. Syringeal (hypoglossal) motor neurons were identified by antidromic activation. Various units were turned on, speeded, slowed, stopped, or caused to fire in repetitive bursts. All units that were antidromically activated by hypoglossal stimulation fired in repetitive bursts with a rhythms which closely resembled that of calling. Many other units also fired in this bursting pattern, and the large majority of them were found at the obex or caudal to it despite extensive search rostrally. The nature of likely inputs to the medullary call neurons is discussed.