Differences in autonomic physiological responses between good and poor inductive reasoners

We investigated individual- and task-related differences in autonomic physiological responses induced by time limited figural and verbal inductive reasoning tasks. In a group of 52 participants, the percentage of correctly responded task items was evaluated together with nine different autonomic physiological response measures and respiration rate (RR). Weighted multidimensional scaling analyses of the physiological responses revealed three underlying dimensions, primarily characterized by RR, parasympathetic, and sympathetic activity. RR and sympathetic activity appeared to be relatively more important response dimensions for poor reasoners, whereas parasympathetic responsivity was relatively more important for good reasoners. These results suggest that poor reasoners showed higher levels of cognitive processing intensity than good reasoners. Furthermore, for the good reasoners, the dimension of sympathetic activity was relatively more important during the figural than during the verbal reasoning task, which was explained in terms of hemispheric lateralization in autonomic function.     

The vestibulospinal reflex in humans: effects on paraspinal muscle activity

OBJECTIVE: To elucidate the electromyographic (EMG) patterns elicited in the superficial paraspinal muscles (sacrospinalis, ileocostalis lomborum, longissimus dorsi and splenium cervicis). MATERIAL AND METHODS: In normal subjects adapted to the dark and standing on a force platform, EMG patterns were elicited in the superficial paraspinal muscles by means of unilateral cold caloric stimulation of the labyrinth. RESULTS: Almost concomitantly with the occurrence of postural derangement of the subject's trunk and head, the EMG patterns of the paraspinal muscles on both sides showed significant and consistent changes. In particular, the paraspinal muscles ipsilateral to the stimulated side showed a significant reduction in activity, while the homologous muscles of the contralateral side markedly increased their activity, with a consistent delay in comparison to the contralateral muscles. Moreover, the EMG changes occurred in a hierarchic fashion in the caudal-rostral direction. In fact, the more powerful and longer-lasting effects were consistently observed in the more caudal muscles, i.e. the sacrospinalis and ileocostalis, while the effects on the longissimus dorsi and splenium cervicis muscles were weak and inconsistent. CONCLUSION: These results suggest a possible use for the EMG patterns resulting from unilateral cold caloric stimulation for clinical evaluation of the vestibulospinal reflex.     

EP 91073 prevents EP 80661-induced penile erection: new evidence for the existence of specific EP peptide receptors mediating penile erection

The effect of EP 91073, EP 51389, EP 70555 and EP 51216, peptide analogues of the growth hormone releasing peptide hexarelin, on penile erection induced by EP 80661 or EP 60761 injected into the paraventricular nucleus of the hypothalamus, was studied in male rats. Of the above peptides only EP 91073 (0.2-1 microg) was found capable of reducing penile erection induced by EP 80661 or EP 60761, when given into the paraventricular nucleus. Despite its ability to prevent EP peptide-induced penile erection, EP 91073 (1 microg) was unable to prevent penile erection induced by the dopamine receptor agonist apomorphine (50 ng), oxytocin (30 ng) and N-methyl-D-aspartic acid (50 ng), when given into the paraventricular nucleus 10 min prior to the above substances. The EP 91073-induced prevention of penile erection occurred with a reduction in the increase in nitric oxide production that occurs in the paraventricular nucleus concomitant to penile erection induced by EP 80661 and EP 60761, as measured by intracerebral vertical microdialysis. The present results are in line with the hypothesis that EP 80661 and EP 60761 induce penile erection by activating specific receptors in the paraventricular nucleus, located possibly in oxytocinergic neurons mediating penile erection, and show that EP 91073 acts as an antagonist of these EP peptide receptors mediating penile erection.     

Frequency-dependent LTP/LTD in guinea pig Deiters' nucleus

Synaptic plasticity was studied in the lateral vestibular nuclei (LVN) of the guinea pig in vivo. High frequency stimulation (HFS) of increasing or decreasing frequencies was applied to the ipsilateral vestibular nerve. Vestibular field potentials (VFPs) and extracellular single unit activity evoked in the LVN by electrical stimulation of the ipsilateral vestibular nerve, were analyzed before and after the application of different protocols of HFS. Results show that the monosynaptic component of the VFPs undergo long-term potentiation (LTP) with stimulation of 100 Hz applied for 20 s lower frequencies, applied for shorter periods, induce only a transient post-tetanic potentiation. This potentiation, although long lasting, is not permanent since it is susceptible of a reversal or cancellation by opposite patterns of HFS that determine a depression or depotentiation of the previously acquired potentiation. The results demonstrate that the plasticity phenomena that take place at the level of the LVN neurons are not steady but undergo continuous adjustment of their sign and gain depending on the variable flow of vestibular information that reach the nuclei from the labyrinthine receptors.     

Role of pH as a regulator of vaginal physiological environment

In the vagina there are several microorganisms. Their survival is fundamental to have a physiological environment in the vagina (ecosystem). The same vaginal environment playg a fundamental role to guarantee tho survival of resident microorganisms. Several factors, like changes of temperature and oxygenation, can interfere on vaginal ecosystem, but the resident vaginal microorganisms are the main factors to stabilize the vaginal ecosystem. The Doderlein's lactobacillus is the predominant vaginal microorganism. It is capable of fermenting the glycogen deriving from the decline of the eutrophic vaginal mmucosa, to lactic acid with release of hydrogen ions. The final result of that metabolism is an acid pH with values between 4-4.5. Vaginal pH undergoes physiologically changes from birth to menopause, according to changes of ovarian steroids occurring during woman's life. Adequate levels of estrogens play a fundamental role in the trophism of vaginal mucosa. In fact, estrogens increase the cellular content of glycogen. Exogenous acbvities on vaginal pH can be exerted by several factors, such as sexual activily, oral contraceptives, systemic diseases, vaginal infections (candidosis, thrichomonias, vaginosis), systemic or local therapies. They incrcase vaginal pH by acting through different mechanisms. The increase of vaginal pH is detrimental for the survival of Doderlein's lactobacillus, but not for the pathogenetic microorganisms whose replication, on the contrary, is favored by the absence of contraction exerted by Doderlein's bacillus. It has been showed that local acidifying substances (lactic acid, lactobacillus and substances recently synthesized like alpha-aminovalerianic acid, policarbophil and carbopol 934) are useful in restoring the biological and chemical characteristics of the vaginal ecosystem.     

C329X in KRIT1 is a founder mutation among CCM patients in Sardinia

Cerebral cavernous malformations (CCMs) are CNS vascular anomalies associated with seizures, headaches and hemorrhagic strokes and represent 10–20% of cerebral lesions. CCM is present in 0.1–0.5 of the population. This disorder most often occurs sporadically but may also be familial. Familial cases are inherited as a dominant trait with incomplete penetrance and are estimated to account for KRIT1 10–40% of the patients. The identification of the genes involved in such disorders allows to characterize carriers of the mutations without clear symptoms. The first gene involved in CCM1 is KRIT1. In addition to two other genes have been described: MGC4607 (CCM2) and PDCD10 (CCM3). We selected 13 patients belonging to seven Sardinian families on the basis of clinical symptoms and Magnetic Resonance results. In MGC4607 gene an undescribed exon five deletion likely producing a truncated protein was identified in one family. In two patients with clear phenotype and in three asymptomatic relatives a 4 bp deletion in exon 9 of KRIT1 gene, leading to a premature stop codon, was detected. A unique nonsense mutation (C329X) has been found in seven patients and two asymptomatic subjects belonging to four unrelated families. Haplotype analysis revealed a common origin of this mutation. These data suggest a “founder effect” in Sardinia for the C329X mutation, similar to other mutations described in different populations.     

Monozygotic twins non-concordant for oligomeganephronic renal hypoplasia: artery-vein placental shunting as a possible pathogenetic mechanism

The etiology and pathogenesis of oligomeganephronic renal hypoplasia (OMN) are not known. In the present paper a second case of monozygotic twins non-concordant for OMN is described. It is hypothesized that one of the mechanisms which have been proposed to explain structural defects in monozygotic twins, namely placental artery-vein shunting, may have been involved in the pathogenesis of OMN in these patients. In OMN in general vascular abnormalities may have to be considered as a pathogenetic mechanism.     

Long-term use of cisapride (Prepulsid) in premature neonates

In order to study the effect of cisapride on gastric stasis and to evaluate the possible risk of cholestasis, 20 premature neonates born in the hospital during one year were orally treated with cisapride 0.15 mg/kg q.i.d., over a mean period of 38 days. The gestational age ranged from 26 to 34 weeks and the mean age at the start of the cisapride treatment was 18 days. All patients were ventilated, 13 had a respiratory distress syndrome (hyaline membrane disease), and 9 had gastro-oesophageal reflux (GOR). All patients were given a semielementary formula by means of a continuous nasogastric infusion. The gastric residue was studied during three days: 24 hour baseline and 48 hours under cisapride treatment. The mean residue decreased (p less than 0.0001) from 50.6% during the last 6 baseline hours to 12.1% during the last 6-hours of the cisapride period. The mean feeding volume increased from 24.2 ml to 34.2 ml (p less than 0.001). A group of four patients had reversible cholestasis against the background of an outbreak of Candida, three before and one during cisapride treatment. Therefore, it could not be demonstrated that cisapride plays a role in the development of cholestasis. Because of the risks of GOR and the drawbacks of delayed enteral feeding, it is concluded that the use of cisapride is justified in premature neonates with gastric stasis.     

Orbital Cellulitis After Strabismus Surgery

Serious infection is uncommon after eye muscle surgery. Orbital cellulitis is a rarely reported but is potentially vision- and life-threatening complication after strabismus surgery. In this report, we describe a case of unilateral orbital cellulitis after strabismus surgery for sensory exotropia in a healthy adolescent boy.