Henrik Jacobsen

The Urethral Plug: A New Treatment Modality for Genuine Urinary Stress Incontinence in Women

A new modality, the urethral plug, was used to treat 22 women with genuine urinary stress incontinence. The plug is made of thermoplastic elastomer (Kraton G), and consists of a meatal plate, a soft stalk and 1 or 2 spheres along the stalk. The spheres were located according to the result of the urethral pressure profile. The midpoint of the proximal sphere was placed at the bladder neck and the distal sphere was placed just above the maximum urethral pressure point. At voiding the plug was removed and afterwards a new plug was inserted. The plug with 2 spheres was tested in week 1 (period 1) and the plug with only the distal sphere was tested in week 2 (period 2). A total of 22 patients completed period 1. Eight patients did not complete period 2, mostly due to either unchanged incontinence during period 1 or a repeated loss of the plug with 1 sphere. In periods 1 and 2, 73 and 79% of the patients were subjectively and objectively continent or improved. A total of 14 patients completed both periods. Eight patients preferred the plug with 2 spheres, 1 preferred the other plug and 5 had no preference. The side effects were few. This preliminary study shows that the urethral plug seems to be a promising alternative treatment for female genuine urinary stress incontinence.

Sexual behaviour related to psycho-social factors in a population of Danish homosexual and bisexual men

An anonymous self-administered questionnaire was distributed to (1) male members of the Danish Gay and Lesbian Association (2) through a gay magazine and (3) to readers of a gay pornographic magazine. For the purpose of this study sexual practices were classified into three categories taking into account the HIV-status of the respondent and his partner(s): safe sex (mutual masturbation, sex with condoms, sex without condoms between two HIV-positives), potentially safe sex (oral-genital sex without condoms irrespective of HIV-status, anal-genital sex without condoms between two HIV-negatives), unsafe sex (anal-genital sex without condoms between discordant partners or partners of unknown HIV status). Of the 2058 respondents 29.7% had had unsafe sex in the last 12 months. Multivariate analysis by recursive graphical models showed that sexual practice was directly related (that is conditionally dependent given the rest of the variables) to having a steady partner. Among men without a steady partner sexual practice was also directly related to age and number of partners showing an increase in unsafe sex with number of partners and a decrease with age. Thus of the men 16-19 years of age 43.5% had had unsafe sex irrespective of number of partners vs 5.7% of men older than 44 years and with one to two partners. Sexual practice was not directly related to any other demographic or psychosocial factor in the study. The adopted classification of sexual practice preclude that the high occurrence of unsafe sex could be explained by unsafe sex taking place among partners of concordant HIV status. The results emphasize the need for further preventive efforts to reduce transmission of HIV among homosexual men.

Hidden order in spin-liquid Gd₃Ga₅O₁₂.

Elucidating order within disorder In some materials, the geometry of the crystal lattice gets in the way of magnetic ordering. Their spins, although magnetically interacting, remain seemingly disordered and form a so-called spin liquid. Paddison et al. propose a different model for the spin-liquid compound Gd3Ga5O12. Neutron diffraction measurements and numerical techniques revealed that even though individual spins in this material were disordered, they formed 10-spin loops that were correlated with one another. The nature of this “hidden order” was such that it escaped direct detection by conventional techniques Science, this issue p. 179 Reverse Monte Carlo refinements of neutron diffraction data are used to deduce a model of ordered 10-spin loops in Gd3Ga5O12. Frustrated magnetic materials are promising candidates for new states of matter because lattice geometry suppresses conventional magnetic dipole order, potentially allowing “hidden” order to emerge in its place. A model of a hidden-order state at the atomic scale is difficult to deduce because microscopic probes are not directly sensitive to hidden order. Here, we develop such a model of the spin-liquid state in the canonical frustrated magnet gadolinium gallium garnet (Gd3Ga5O12). We show that this state exhibits a long-range hidden order in which multipoles are formed from 10-spin loops. The order is a consequence of the interplay between antiferromagnetic spin correlations and local magnetic anisotropy, which allows it to be indirectly observed in neutron-scattering experiments.

Risk factors related to the 7-year prognosis for patients suspected of myocardial infarction with and without confirmed diagnosis.

This study prospectively evaluates the long-term prognosis of patients admitted with chest pain under suspicion of acute myocardial infarction (AMI) with and without confirmed diagnosis. All patients below 76 years of age, free of other severe diseases and alive at discharge, who were admitted to a coronary care unit of a well-defined region during 1 year, constituted the study population. In all, 275 patients with and 257 patients without confirmed AMI (non-AMI) were included. During 7 years of follow-up, 122 cardiac events (96 cardiac deaths and 26 nonfatal AMI) occurred in the AMI patients, and 69 (44 cardiac deaths and 25 nonfatal AMI) were observed in the non-AMI patients. Using univariate analysis, the following risk variables were significantly related to an impaired prognosis of non-AMI patients: age, a history of previous AMI, angina pectoris, clinical heart failure, diabetes and ST or T changes in the electrocardiogram (ECG) on admission. By multivariate analysis, the following risk factors contained independent prognostic information for non-AMI patients: (1) a history of angina pectoris and (2) ST and T changes on the ECG on admission. We conclude that a subset of non-AMI patients at high risk for cardiac events even in the long term can be identified from the medical history and the ECG on admission. These patients should be carefully evaluated prior to discharge, whereas patients without signs of ischemic heart disease have an excellent prognosis.

The long-term predictive value of an exercise thallium-201 scintigraphy for patients with acute chest pain but without myocardial infarction.

BackgroundPatients who are hospitalized because of chest pain and suspected acute myocardial infarction, but in whom the diagnosis is ruled out, are at high risk for subsequent cardiac events (cardiac death or nonfatal acute myocardial infarction). Risk stratification was done for 158 such patients who underwent exercise thallium-201 scintigraphy at the time of discharge. MethodsThirty-eight patients (24%) were women, and all patients were followed for 7 years. The diagnostic sensitivity, specificity, and predictive value of thallium scintigraphy for the identification of patients having subsequent cardiac events during follow-up was calculated. ResultsA cardiac event occurred in 41 patients during the follow-up period. Presence of both transient and permanent defects and abnormal ST-segment responses during thallium scintigraphy were significantly associated with an impaired prognosis (P< 0.0001). The highest sensitivity (85%) was achieved by the combination of transient defect with or without persistent defect and with or without abnormal ST-segment response. The highest specificity was provided by a transient defect (90%), and the predictive value of a positive test result was 60%. Seventeen of 29 patients with a transient defect had a cardiac event during follow-up. Patients with normal test results had excellent prognoses; 93% of 82 patients were free of cardiac events during follow-up. ConclusionsExercise thallium-201 scintigraphy is suitable for long-term risk stratification in patients with chest pain and suspected but unconfirmed myocardial infarction, because high- and very low-risk subsets can be identified at the time of discharge.

Neutron scattering study of spin ordering and stripe pinning in superconducting La1.93Sr0.07CuO4

The relationships among charge order, spin fluctuations, and superconductivity in underdoped cuprates remain controversial. We use neutron scattering techniques to study these phenomena in La1.93Sr0.07CuO4 a superconductor with a transition temperature of Tc = 20 K. At T<< Tc, we find incommensurate spin fluctuations with a quasielastic energy spectrum and no sign of a gap within the energy range from 0.2 to 15 meV. A weak elastic magnetic component grows below ~ 10 K, consistent with results from local probes. Regarding the atomic lattice, we have discovered unexpectedly strong fluctuations of the CuO6 octahedra about Cu-O bonds, which are associated with inequivalent O sites within the CuO2 planes. Moreover, we observed a weak elastic (3 ⁻30) superlattice peak that implies a reduced lattice symmetry. The presence of inequivalent O sites rationalizes various pieces of evidence for charge stripe order in underdoped La2-xSrxCuO4. The coexistence of superconductivity with quasi-static spin-stripe order suggests the presence of intertwined orders; however, the rotation of the stripe orientation away from the Cu-O bonds might be connected with evidence for a finite gap at the nodal points of the superconducting gap function.

Probing the dynamics of complexed local anesthetics via neutron scattering spectroscopy and DFT calculations

Since potential changes in the dynamics and mobility of drugs upon complexation for delivery may affect their ultimate efficacy, we have investigated the dynamics of two local anesthetic molecules, bupivacaine (BVC, C18H28N2O) and ropivacaine (RVC, C17H26N2O), in both their crystalline forms and complexed with water-soluble oligosaccharide 2-hydroxypropyl-β-cyclodextrin (HP-β-CD). The study was carried out by neutron scattering spectroscopy, along with thermal analysis, and density functional theory computation. Mean square displacements suggest that RVC may be less flexible in crystalline form than BVC, but both molecules exhibit very similar dynamics when confined in HP-β-CD. The use of vibrational analysis by density functional theory (DFT) made possible the identification of molecular modes that are most affected in both molecules by insertion into HP-β-CD, namely those of the piperidine rings and methyl groups. Nonetheless, the somewhat greater structure in the vibrational spectrum at room temperature of complexed RVC than that of BVC, suggests that the effects of complexation are more severe for the latter. This unique approach to the molecular level study of encapsulated drugs should lead to deeper understanding of their mobility and the respective release dynamics.

Field-induced interplanar magnetic correlations in the high-temperature superconductor La1.88Sr0.12CuO4

We present neutron scattering studies of the inter-planar correlations in the high-temperature superconductor La1.88Sr0.12CuO4 (T_c=27 K). The correlations are studied both in a magnetic field applied perpendicular to the CuO2 planes, and in zero field under different cooling conditions. We find that the effect of the magnetic field is to increase the magnetic scattering signal at all values of the out-of-plane wave vector L, indicating an overall increase of the magnetic moments. In addition, weak correlations between the copper oxide planes develop in the presence of a magnetic field. This effect is not taken into account in previous reports on the field effect of magnetic scattering, since usually only L~0 is probed. Interestingly, the results of quench-cooling the sample are similar to those obtained by applying a magnetic field. Finally, a small variation of the incommensurate peak position as a function of L provides evidence that the incommensurate signal is twinned with the dominating and sub-dominant twin displaying peaks at even or odd L, respectively.

Updating the phase diagram of the archetypal frustrated magnet Gd3Ga5O12

The applied magnetic field and temperature phase diagram of the archetypal frustrated magnet, Gd3Ga5O12, has been reinvestigated using single-crystal magnetometry and polarized neutron diffraction. The updated phase diagram is substantially more complicated than previously reported and can be understood in terms of competing interactions with loops of spins, trimers, and decagons, in addition to competition and interplay between antiferromagnetic, incommensurate, and ferromagnetic order. Several additional distinct phase boundaries are presented. The phase diagram centers around a multiphase convergence to a single point at 0.9 T and similar to 0.35 K, below which, in temperature, a very narrow magnetically disordered region exists. These data illustrate the richness and diversity that arise from frustrated exchange on the three-dimensional hyperkagome lattice. (Less)

Encapsulation effects on the structure-dynamics on drug carriers revealed by neutron scattering

Universidade Estadual Paulista Julio de Mesquita Filho, Departamento de Quimica, Instituto de Biociencias, Botucatu, Distrito de Rubiao Junior, Rubiao Junior, CEP 18618000, SP, Brasil