Investigation of Na+,K+-ATPase on a solid supported membrane: the role of acylphosphatase on the ion transport mechanism

AbstractCharge translocation by Na+,K+-ATPase was investigated by adsorbing membrane fragments containing Na+,K+-ATPase from pig kidney on a solid supported membrane (SSM). Upon adsorption, the ion pumps were activated by performing ATP concentration jumps at the surface of the SSM, and the capacitive current transients generated by Na+,K+-ATPase were measured under potentiostatic conditions. To study the behavior of the ion pump under multiple turnover conditions, ATP concentration jump experiments were carried out in the presence of Na+ and K+ ions. Current transients induced by ATP concentration jumps were also recorded in the presence of the enzyme α-chymotrypsin. The effect of acylphosphatase (AcP), a cytosolic enzyme that may affect the functioning of Na+,K+-ATPase by hydrolyzing its acylphosphorylated intermediate, was investigated by performing ATP concentration jumps both in the presence and in the absence of AcP. In the presence of Na+ but not of K+, the addition of AcP causes the charge translocated as a consequence of ATP concentration jumps to decrease by about 50% over the pH range from 6 to 7, and to increase by about 20% at pH 8. Conversely, no appreciable effect of pH upon the translocated charge is observed in the absence of AcP. The above behavior suggests that protons are involved in the AcP-catalyzed dephosphorylation of the acylphosphorylated intermediate of Na+,K+-ATPase

Acupressure in the control of migraine-associated nausea

Migraine is a disabling neurological disorder, aggravated by accompanying symptomatology, such as nausea. One of the most interesting approaches to nausea adopted by traditional Chinese medicine is the stimulation of the acupoint PC6 Neiguan. Actually there are no studies in medical literature as to the efficacy of treating PC6 acupoint for gastrointestinal symptoms in migraine attacks. Our study aimed at verifying if pressure applied to the acupoint PC6 was effective on nausea during migraine. Forty female patients suffering from migraine without aura were enrolled, if nausea was always present as accompanying symptomatology of their migraine. The patients were treated randomly for a total of six migraine attacks: three with the application of a device, the Sea-Band® wristband, which applies continual pressure to the PC6 acupoint (phase SB), and three without it (phase C). The intensities of nausea at the onset, at 30, 60, 120 and 240 min were evaluated on a scale from 0 to 10. The values were always significantly lower in phase SB than in phase C. Also the number of patients who reported at least a 50 % reduction in the nausea score was significantly higher in phase SB than in phase C at 30, 60 and 120 min. Moreover, the consistency of the treatment (response in at least two out of three treated attacks) was reached in 28 % patients at 60 min; in 40 % at 120 min and 59 % at 240 min. Our results encourage the application of PC6 acupressure for the treatment of migraine-associated nausea

The involvement of early stage breast cancer patients during oncology consultations in Italy: a multi-centred, randomized controlled trial of a question prompt sheet versus question listing

OBJECTIVES: To investigate, prior to an oncology consultation, the use of a pre-prepared list of evidence based questions, Question Prompt Sheet (QPS), compared with a Question List (QL), a patient self-generated list of questions. DESIGN: Multi-centred, randomised controlled trial. SETTING: Secondary-care patients attending three outpatient oncology clinics in Northern Italy. PARTICIPANTS: 308 women completed the study. Inclusion criteria were an age between 18 and 75 years, a recent diagnosis of early stage, non-metastatic breast cancer, adequate Italian language skills, no previous oncology visits and no evidence of cognitive impairment. INTERVENTION: Patients received the QPS or the QL prior to the consultation, completed it without suggestion or coaching session and delivered back before the visit.The consultations were audio-recorded and analysed for the number and content of questions. Multilevel linear models were used to compare the two groups. OUTCOME MEASURES: The primary outcome was the comparison of questions asked between QPS and QL group. Secondary outcomes included satisfaction about questions asked, satisfaction with decision, and level of anxiety. RESULTS: Patients in the QPS and QL group asked 13 and 16 questions respectively. The difference was not significant (b=1.7, CI -0.3 to 3.6, p=0.10). A mean of 22 questions was selected in the QPS, while a mean of 2 questions was written in the QL. Patients in the QPS group were significantly less satisfied (t=3.60, p<0.01) with questions asked but wanted less additional information (t=2.20, p<0.05). Levels of patient decisional satisfaction were equivalent between groups. Similarly, anxiety levels were equal between groups prior to the consultation and decreased in similar way after the consultation. CONCLUSIONS: Both interventions have similar impact on patients' participation in terms of question asking during the consultation. Future research is needed in order to explore which components of the interventions are really useful and efficacious. TRIAL REGISTRATION: ClinicalTrials.gov NCT01510964