Identification of brainstem neurons responding to hypoxia in fetal and newborn sheep

Hypoxia causes a reversible decrease in the level of respiratory, oculomotor and postural muscle activity in fetal sheep, an effect not seen in newborn lambs. We have used Fos immunohistochemistry to identify neurons which are activated by hypoxia and which may mediate this motor inhibition in the fetus. Pregnant sheep of either 117 or 138 days gestation were made hypoxic by allowing them to breathe 8-9% O2 for 2 h. Compared to age-matched control fetuses, hypoxia caused a significant increase in Fos-immunoreactivity in several medullary nuclei including the nucleus tractus solitarius, lateral reticular nucleus and the rostral ventrolateral medulla and also in the lateral parabrachial nucleus, locus coeruleus and subcoeruleus region in the pons. Hypoxia in newborn lambs, 7-18 days old, resulted in Fos staining in the same medullary and pontine nuclei with the exception of the subcoeruleus region which was devoid of Fos-immunoreactivity. In newborn lambs in which the carotid sinus nerves had been sectioned bilaterally, Fos-immunoreactivity was increased in the nucleus tractus solitarius in the medulla and in the locus coeruleus, lateral parabrachial and K?lliker-Fuse nuclei in the pons when compared to intact control newborn lambs. When carotid sinus nerve denervated-lambs were subjected to hypoxia the pattern of Fos-ir was similar to the pattern seen in the denervated control lambs but in addition staining was present in the subcoeruleus. These results suggest that a specific set of pontine neurons are activated by low oxygen levels in the fetus but not in the newborn lamb in the presence of an intact innervation from the carotid sinus. We hypothesise that: (a) in the fetus hypoxia activates neurons in the region of the subcoeruleus and this causes cessation of breathing movements and muscle atonia; and (b) that after birth stimulation of the carotid chemoreceptors by hypoxia normally inhibits activation of these subcoeruleus neurons.     

The fluoride content of teeth in the canton of Vaud 5 years after the introduction of salt fluoridation

Fluroide concentrations in teeth from the canton of Vaud were about at the same level reported from regions with 1,0 ppm F in the drinking water and from children receiving fluoride tablets during tooth formation age.     

Effect of cortisone on post-traumatic regeneration of mammalian skeletal muscle

Prolonged administration of cortisone to sexually immature rabbits and rats, in which m. tibialis anterior was injured preliminarily, inhibited the process of regeneration of the skeletal muscle tissue; this was expressed in the retarded growth of myosymplasts and of the muscle tubes. By the 15th postoperative day experimental rabbits (in comparison with control) showed a lesser area of muscle component of the regenerated tissue. Analysis of the intensity of methionine-H3 incorporation into the regenerating elements of the muscle tissue demonstrated a significant reduction of the label incorporation into the nuclear and cytoplasmic proteins of the myosymplasts of rats to which cortisone was given. Inhibition of the protein synthesis at the early stage of differentiation of the muscle tissue was expressed to a lesser extent than in the mature differentiated muscle fibers of the intact muscle.     

Sources of cognitive conflict for stage transition in moral development.

Examined processes of moral-stage transition by comparing the efficacy of various conditions of cognitive conflict for inducing moral development (MD). These conditions could involve 2 sources of conflict: (a) opinions regarding solutions to moral dilemmas and (b) stage of supportive reasoning. 117 5th–7th graders were pretested to determine their stages of cognition, perspective-taking, and MD. The 60 Ss with the necessary stages of cognitive and perspective-taking development for further MD were exposed, in a brief role-playing situation, to one of the intervention conditions. These conditions presented either conflicting or consonant opinions that were supported by reasoning either at the S's own stage or at the next higher stage. Moral reasoning posttests followed after 1 and 7 wks. Results indicate that conflict in both opinions and reasoning induced the greatest MD, although conflict in either opinions or reasoning alone was moderately effective. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motor proficiency and attentional-task performance by psychotic patients.

Investigated the relation between motor proficiency and performance on the Continuous Performance Test (CPT) among 24 schizophrenic inpatients (mean age 34 yrs) and 24 inpatients with affective disorders (mean age 33.8 yrs). Ss completed the Bruininks-Oseretsky Test of Motor Proficiency. A correlational analysis revealed that motor subtest scores were significantly related to CPT performance indexes for all Ss; decreased motor proficiency was related to more CPT errors and longer RTs. Results suggest that CPT performance is related to motoric factors and that deficits on this task may be partially attributable to poor motor abilities. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)