Inhibition in the somatosensory system: An integrative neuropharmacological and neuroimaging approach.

The presented study investigates the functional role of GABA in somatosensory processing, using a combined neuropharmacological-neuroimaging approach. Three different GABA agonists (GABAA: alprazolam, ethanol; GABAB: baclofen) were investigated in a double blind cross-over design in 16 male participants, accomplishing a tactile perception task. Somatosensory evoked magnetic fields modulated by GABAR-agonists and placebo were recorded using whole-head magnetoencephalography. Peak latencies and amplitudes of primary (SI) and secondary (SII) somatosensory cortex source activities confirmed the previously reported role of GABA as a modulator of somatosensory processing. Significant inhibitory effects on the latency of SII and on the amplitude of SI and SII were found exclusively for alprazolam, a positive allosteric modulator at GABAA receptors. The GABAB agonist baclofen did not have any modulatory effect. Moreover, we investigated whether the observed effects of alprazolam on the level of SII were explainable by the mere propagation of activity from SI to SII modulated by GABAA receptors, independently from any further GABAA-mediated inhibition in SII. By estimating the transfer function between SI and SII activation under placebo conditions, we were able to predict SII activity for the administration of GABA receptors agonists under the assumption that GABA exclusively acts at the level of SI. By comparing measured and predicted data, we propose a model in which the initial activation of SI is modulated through GABAA receptors and subsequently propagated to SII, without any significant further inhibition. In addition, initial GABAA effects in SI appear to be strongly potentiated with time, selectively in SI but not in SII.

Nuclear Phosphoinositides: Their Regulation and Roles in Nuclear Functions.

Polyphosphoinositides (PPIns) are a family of seven lipid messengers that regulate a vast array of signalling pathways to control cell proliferation, migration, survival and differentiation. PPIns are differentially present in various sub-cellular compartments and, through the recruitment and regulation of specific proteins, are key regulators of compartment identity and function. Phosphoinositides and the enzymes that synthesise and degrade them are also present in the nuclear membrane and in nuclear membraneless compartments such as nuclear speckles. Here we discuss how PPIns in the nucleus are modulated in response to external cues and how they function to control downstream signalling. Finally we suggest a role for nuclear PPIns in liquid phase separations that are involved in the formation of membraneless compartments within the nucleus.

Acute abdominal pain due to internal herniation of the sigmoid colon, fallopian tube and left ovary, a rare presentation of Allen Masters syndrome.

In 1955, Allen and Masters describe a painful syndrome which associates traumatic delivery to laceration found on the posterior leaf of the broad ligament. Herniation through this defect is a rare entity, accounted for about 4-7% of all internal hernias. Normally, it involves the small bowel. The authors present the case of a multiparous woman admitted at emergency for constipation and abdominal pain. The CT scan showed an extremely rare case of internal hernia of the sigmoid colon, fallopian tube and left ovary through a large defect of the broad ligament. The patient underwent a full laparoscopic surgery that allowed the reduction of the hernia and the suture of the defect with very good outcome.

[Prevention of postoperative nausea and vomiting with ondansetron: a prospective, randomized, double-blind study in 90 patients]. / Profilassi della nausea e del vomito postoperatori con ondansetron: studio prospettico e randomizzato, condotto in doppio cieco, su 90 pazienti.

Postoperative nausea and vomiting (PONV) are among the most common complications in surgical patients. In this prospective, double blind, parallel group study we compare the prophylactic antiemetic efficacy of ondansetron versus placebo in 90 patients undergoing general balanced anaesthesia. The patients were stratified according to the kind of surgery and randomly allocated to three treatment groups: 30 patients (Group A) received ondansetron 4 mg i.v. 1 hour before the induction of anaesthesia and placebo 1 hour before the end of surgery; 30 patients (Group B) received placebo 1 hour before the end of anaesthesia and ondansetron 4 mg i.v. 1 hour before the end of surgery; 30 patients (Group C-control group) received placebo in both the administrations. Data were analyzed by Student t test and chi 2 test; significance was taken at p < 0.05. The three groups proved comparable with respect to demographic characteristics, duration of anaesthesia and fentanyl consumption. Analysis of the results showed that PONV had a significantly lower incidence in treated patients (Groups A and B) than in the control group patients (Group C): postoperative nausea occurred in 13%, 30% and 67% of patients in Group A, B and C respectively and it was associated with vomiting in 3%, 7% and 57% of patients in Group A, B and C respectively. Although the patients in Group A showed a lower incidence of PONV in comparison to the patients in Group B, such differences proved to be not statistically significant. No adverse effects in relation to drug administration were observed. We conclude that ondansetron 4 mg i.v. is safe and effective in preventing PONV in the surgical patients, particularly when administered before the induction of anaesthesia.