Ion Dynamics at the Magnetopause of Ganymede.

We study the dynamics of the thermal O+ and H+ ions at Ganymede's magnetopause when Ganymede is inside and outside of the Jovian plasma sheet using a three-dimensional hybrid model of plasma (kinetic ions, fluid electrons). We present the global structure of the electric fields and power density (E â‹… J) in the magnetosphere of Ganymede and show that the power density at the magnetopause is mainly positive and on average is +0.95 and +0.75 nW/m3 when Ganymede is inside and outside the Jovian plasma sheet, respectively, but locally it reaches over +20 nW/m3. Our kinetic simulations show that ion velocity distributions at the vicinity of the upstream magnetopause of Ganymede are highly non-Maxwellian. We investigate the energization of the ions interacting with the magnetopause and find that the energy of those particles on average increases by a factor of 8 and 30 for the O+ and H+ ions, respectively. The energy of these ions is mostly within 1-100 keV for both species after interaction with the magnetopause, but a few percentages reach to 0.1-1 MeV. Our kinetic simulations show that a small fraction ( < 25%) of the corotating Jovian plasma reach the magnetopause, but among those >50% cross the high-power density regions at the magnetopause and gain energy. Finally, we compare our simulation results with Galileo observations of Ganymede's magnetopause crossings (i.e., G8 and G28 flybys). There is an excellent agreement between our simulations and observations, particularly our simulations fully capture the size and structure of the magnetosphere.

Association between population density and reported incidence, characteristics and outcome after out-of-hospital cardiac arrest in Sweden.

AIM: To describe the reported incidence of out of hospital cardiac arrest (OHCA) and the characteristics and outcome after OHCA in relation to population density in Sweden. METHODS: All patients participating in the Swedish Cardiac Arrest Register between 2008 and 2009 in (a) 20 of 21 regions (n=6457) and in (b) 165 of 292 municipalities (n=3522) in Sweden, took part in the survey. RESULTS: The regional population density varied between 3 and 310 inhabitants per km(2) in 2009. In 2008-2009, the number of reported cardiac arrests varied between 13 and 52 per 100,000 inhabitants and year. Survival to 1 month varied between 2% and 14% during the same period in different regions. With regard to population density, based on municipalities, bystander CPR (p=0.04) as well as cardiac etiology (p=0.002) were more frequent in less populated areas. Ambulance response time was longer in less populated areas (p<0.0001). There was no significant association between population density and survival to 1 month after OHCA or incidence (adjusted for age and gender) of OHCA. CONCLUSION: There was no significant association between population density and survival to 1 month after OHCA or incidence (adjusted for age and gender) of OHCA. However, bystander CPR, cardiac etiology and longer response times were more frequent in less populated areas.

Straightforward and rapid determination of sulfadoxine and sulfamethoxazole in capillary blood on sampling paper with liquid chromatography and UV detection.

A method for the determination of sulfadoxine and sulfamethoxazole in capillary blood on sampling paper has been developed and validated. The method is straightforward with minimal sample preparation, and is suitable for rural settings. Separation of sulfadoxine, sulfamethoxazole and internal standard was performed using a Purospher STAR RP-18 endcapped LC column (150x4.6mm) with a mobile phase consisting of acetonitrile:sodium acetate buffer pH 5.2, I=0.1 (1:2, v/v). For sulfadoxine, the within-day precision was 5.3% at 15micromol/l and 3.7% at 600micromol/l, while for sulfamethoxazole it was 5.7% at 15micromol/l and 3.8% at 600micromol/l. The lower limit of quantification was determined to 5micromol/l and precision was 5.5% and 5.0% for sulfadoxine and sulfamethoxazole, respectively.

Importance of pre-analytical factors contributing to measurement uncertainty, when determining sulfadoxine and sulfamethoxazole from capillary blood dried on sampling paper.

A bioanalytical method is developed and validated for determination of sulfadoxine (SD) and sulfamethoxazole (SM) in 100 microL capillary blood dried on sampling paper (Whatman 31ET Chr). SD and SM are extracted with 2000 microL perchloric acid and the liquid phase is loaded onto ENV+ solid-phase extraction columns. SD, SM, and the internal standard are separated on a Purospher STAR RP-18 liquid chromatography column (150 x 4.6 mm) with a mobile phase consisting of acetonitrile-sodium acetate buffer pH 5.2, I = 0.1 (33:67, v/v). Analytes are detected with UV at 256 nm. Lower limit of quantitation is 5 micromol/L, where precisions are 4.2% and 3.9% for SD and SM, respectively. Three brands of sampling papers have been compared with respect to absorption properties, extraction recoveries, and variations. Punching out dried blood spots (DBS) instead of cutting spots into strips prior to extraction has been evaluated by examining precision and accuracy of SD and SM determinations. Importance of uniformity of types of sampling paper, sampling volume and biological matrix, benefit of punching out discs from DBS, and impact on absorption properties of different brands of sampling papers are discussed. Avoiding pre-analytical errors whenever possible results in concentrations determined being more accurate and precise.

Is there a difference between women and men in characteristics and outcome after in hospital cardiac arrest?

AIM: To describe the characteristics and outcome among patients suffering from an in-hospital cardiac arrest in women and men. METHODS: All patients who suffered an in-hospital cardiac arrest during a 4 year period in Sahlgrenska Hospital Göteborg, Sweden, where the cardiopulmonary resuscitation (CPR) team was called, were recorded and described prospectively in terms of characteristics and outcome. RESULTS: There were 557 patients suffering in-hospital cardiac arrest in whom the CPR-team was alerted. Among them, 217 (39%) were women. Women differed from men having a lower prevalence of earlier myocardial infarction, angina pectoris, renal disease and a higher prevalence of rheumatic disease. In terms of aetiology of the cardiac arrest, 47% men and 48% women were judged to have had a confirmed or possible AMI. More men than women were found in ventricular fibrillation/ventricular tachycardia (VF/VT) (57 vs. 41%; P<0.001), whereas more women were found in pulseless electrical activity (30 vs. 15%; P<0.0001). Cerebral performance categories (CPC)-score at discharge did not differ between men and women. Among women, 36.4% survived to discharge as compared with 38.0% among men (NS). Survival from VF/VT was 64.3% in women and 52.7% in men (NS). When correcting for dissimilarities at baseline, the adjusted odd ratio for being discharged alive from hospital among women as compared with men was 1.66 (95% confidence limit 1.06-2.62; P=0.028). CONCLUSION: Thirty nine percent of patients suffering in-hospital cardiac arrest for whom the CPR-team was alerted, were women. Women were less frequently found in VF/VT than men. After correcting for dissimilarities at baseline, female gender was associated with a small improvement in survival.

Effect of intravenous metoprolol before hospital admission on chest pain in suspected acute myocardial infarction.

BACKGROUND: The aim of this study was to describe the effect of intravenous metoprolol on the intensity of chest pain before hospital admission in patients with suspected acute myocardial infarction AMI). METHODS AND RESULTS: Two hundred sixty-two patients with acute chest pain and suspected AMI were randomly assigned before hospital admission to either 5 mg morphine plus metoprolol 5 mg x 3 intravenously or 5 mg morphine plus intravenous placebo. Chest pain was evaluated on a 10-grade scale before and for 60 minutes after intravenous injection. One hundred thirty-four patients were randomly assigned to metoprolol and 128 to placebo. Among all patients randomized to metoprolol, the mean chest pain score was reduced by 3.0 +/- 1.9 arbitrary units AU) from before to after intravenous injection compared with 2.6 +/- 2.1 AU for placebo not significant). Among patients with an initially confirmed or strong suspicion of AMI, the corresponding figures were 3.1 +/- 1.8 AU for metoprolol and 2.2 +/- 1.6 AU for placebo P =.02). Among patients with only a vague or moderate suspicion of AMI, there was no difference. The treatment was well tolerated. CONCLUSIONS: When all patients were included in the analyses, there was no significant difference with regard to reduction of chest pain in the patients randomly assigned to metoprolol compared with placebo. A retrospective subgroup analysis indicated a beneficial effect of metoprolol among patients with an initially strong suspicion of or confirmed AMI. Further investigations are warranted to confirm this finding.

Rhythm changes during resuscitation from ventricular fibrillation in relation to delay until defibrillation, number of shocks delivered and survival.

AIM: To describe rhythm changes during the initial phase of resuscitation from ventricular fibrillation in relation to the interval between collapse and defibrillation, to survival and to bystander-initiated cardiopulmonary resuscitation (CPR). PATIENTS: All patients who suffered out-of-hospital cardiac arrest between 1980 and 1992, who were reached by the emergency medical service system (EMS), in whom resuscitation attempts were initiated and who were found in ventricular fibrillation. RESULTS: In all, 1216 patients were included in the study. Among patients who converted to a pulse-generating rhythm after the first defibrillation (n = 119) were 56% discharged from hospital as compared with 6% among patients who converted to asystole. The corresponding figures after the third defibrillation were 49% and 2%, respectively, and after the fifth defibrillation 28% and 7%, respectively. Among patients in whom the first defibrillation took place less than 5 min after collapse, 28% directly converted to a pulse-generating rhythm as compared with 3% when the first defibrillation took place 12 min or more after collapse. CONCLUSION: Among patients who suffer out-of-hospital cardiac arrest and are found in ventricular fibrillation, there is a strong relationship between survival and initial rhythm changes after defibrillation. These rhythm changes are directly related to the interval between collapse and the first defibrillation.

Lidocaine in out-of-hospital ventricular fibrillation. Does it improve survival?

BACKGROUND: A large proportion of cardiac arrests outside hospital are caused by ventricular fibrillation. Although it is frequently used, the exact role for treatment with lidocaine in these patients remains to be determined. AIM: To describe the proportion of patients with witnessed out-of-hospital cardiac arrest found in ventricular fibrillation who survived and were discharged from hospital in relation to whether they were treated with lidocaine prior to hospital admission. PATIENTS AND TREATMENT: All the patients with out-of-hospital cardiac arrest found in ventricular fibrillation in Göteborg between 1980 and 1992 in whom cardiopulmonary resuscitation (CPR) was initiated by our emergency medical service (EMS). During the observation period, some of the EMS staff were authorized to give medication and some were not. RESULTS: In all, 1,360 patients were found in ventricular fibrillation, with detailed information being available in 1,212 cases (89%). Lidocaine was given in 405 of these cases (33%). Among patients with sustained ventricular fibrillation, those who received lidocaine had a return of spontaneous circulation (ROSC) more frequently (P < 0.001) and were hospitalized alive more frequently (38% vs. 18%, P < 0.01). However, the rate of discharge from hospital did not significantly differ between the two groups. Among patients who were converted to a pulse-generating rhythm, those who received lidocaine on that indication were more frequently alive than those who did not receive such treatment (94% vs. 84%; P < 0.05). However, the rate of discharge did not significantly differ between the two groups. CONCLUSION: In a retrospective analysis comparing patients who received lidocaine with those who did not in sustained ventricular fibrillation and after conversion to a pulse-generating rhythm, such treatment was associated with a higher rate at ROSC and hospitalization but was not associated with an increased rate of discharge from hospital.