Scanning Compton X-ray microscopy

X-ray microscopy offers the opportunity to image biological and radiosensitive materials without special sample preparations, bridging optical and electron microscopy capabilities. However, the performance of such microscopes, when imaging radiosensitive samples, is not limited by their intrinsic resolution, but by the radiation damage induced on such samples. Here, we demonstrate a novel, to the best of our knowledge, radio-efficient microscope, scanning Compton X-ray microscopy (SCXM), which uses coherently and incoherently (Compton) scattered photons to minimize the deposited energy per unit of mass for a given imaging signal. We implemented SCXM, using lenses capable of efficiently focusing 60 keV X-ray photons into the sub-micrometer scale, and probe its radio-efficient capabilities. SCXM, when implemented in high-energy diffraction-limited storage rings, e.g., European Synchrotron Radiation Facility Extremely Brilliant Source and PETRA IV, will open the opportunity to explore the nanoscale of unstained, unsectioned, and undamaged radiosensitive materials.

Measurement of the helicity asymmetry E for the reaction γ p → π 0 p : The CBELSA/TAPS Collaboration

A measurement of the double-polarization observable E for the reaction γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C4 H9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range fromE γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

Observation of the pη^{'} Cusp in the New Precise Beam Asymmetry Σ Data for γp→pη

Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748  MeV to W=2045  MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447  MeV (W=1896  MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.

N(1520) 3/2(-) helicity amplitudes from an energy-independent multipole analysis based on new polarization data on photoproduction of neutral pions

New data on the polarization observables T, P, and H for the reaction γp→pπ(0) are reported. The results are extracted from azimuthal asymmetries when a transversely polarized butanol target and a linearly polarized photon beam are used. The data were taken at the Bonn electron stretcher accelerator ELSA using the CBELSA/TAPS detector. These and earlier data are used to perform a truncated energy-independent partial wave analysis in sliced-energy bins. This energy-independent analysis is compared to the results from energy-dependent partial wave analyses.

First measurement of the helicity asymmetry for γp → pπ0 in the resonance region

The first measurement of the helicity dependence of the photoproduction cross section of single neutral pions off protons is reported for photon energies from 600 to 2300 MeV, covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, and BnGa partial wave analyses. Strikingly large differences between data and predictions are observed, which are traced to differences in the helicity amplitudes of well-known and established resonances. Precise values for the helicity amplitudes of several resonances are reported.

Well-established nucleon resonances revisited by double-polarization measurements

The first measurement is reported of the double-polarization observable G in the photoproduction of neutral pions off protons, covering the photon energy range from 620 to 1120 MeV and the full solid angle. G describes the correlation between the photon polarization plane and the scattering plane for protons polarized along the direction of the incoming photon. The observable is highly sensitive to contributions from baryon resonances. The new results are compared to the predictions from SAID, MAID, and BnGa partial wave analyses. In spite of the long-lasting efforts to understand γp→pπ(0) as the simplest photoproduction reaction, surprisingly large differences between the new data and the latest predictions are observed which are traced to different contributions of the N(1535) resonance with spin parity J(P)=1/2(-) and N(1520) with J(P)=3/2(-). In the third resonance region, where N(1680) with J(P)=5/2(+) production dominates, the new data are reasonably close to the predictions.

Anamnese und urodynamischer Befund bei inkontinenten Frauen

The history and urodynamic findings correlate with each other in only 52% of the cases. The best correlation was in cases of stress incontinence. The least correlation occurred in cases of mixed incontinence. The best choice for the surgical and pharmacological management of urinary incontinence in women is based on a review of all collected findings and on knowledge of the physiology and anatomy of urinary incontinence.

First measurement of the transverse spin asymmetries of the deuteron in semi-inclusive deep inelastic scattering

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.

Alloplastic replacement of the urinary bladder

PURPOSE

The loss of a functioning bladder is nowadays mostly managed by replacement with gastrointestinal segments. Management of these urinary diversions is difficult and the long-term effects are unknown. We developed a silicone rubber prosthesis for alloplastic replacement of the urinary bladder and tested it in an animal experiment.

MATERIAL AND METHODS

Two artificial bladders were implanted into subcutaneous pockets on each side of the anterior abdominal wall. Cystectomy was performed and each prosthesis was connected to one kidney. Distally, a Y-shaped tube sutured to the urethral stump joined the two bladder outlets. The whole system was successfully implanted in 5 sheep with a mean follow-up of 11.5 months (5-19 months).

RESULTS

Adequate capacity, effective and reliable mechanical function and patent anastomoses to the renal pelvis and the urethra could be achieved. Blood chemistry and renal ultrasound were performed at regular intervals demonstrating neither morphological nor functional deterioration of the renal parenchyma. Histopathological examination in the end of the experiment confirmed the excellent clinical results.

CONCLUSIONS

The positive outcome of these animal experiments suggests this system would be useful for human bladder substitution. Standardized industrial production of the prostheses will be needed prior to implantation in humans.

Randomized, double-blind, multicenter trial on treatment of frequency, urgency and incontinence related to detrusor hyperactivity: oxybutynin versus propantheline versus placebo

Clinical efficacy and adverse effects of oxybutynin and propantheline in the treatment of symptoms related to detrusor hyperactivity were studied in a randomized, controlled, double-blind multicenter trial. Of 169 patients entered into the study 154 were evaluable for statistical analysis. Mean grade of improvement (visual analogue scale) was significantly higher with oxybutynin (58.2%) versus propantheline (44.7%) and placebo (43.4%). Mean bladder volume at first involuntary cystometric contraction was significantly increased with oxybutynin (+57.0 ml.) versus placebo (-9.7 ml.). Mean maximum cystometric bladder capacity was also significantly increased with oxybutynin (+80.1 ml.) versus placebo (+22.5 ml.). Rate of inquired possible adverse effects was significantly higher for oxybutynin (63%) versus propantheline (44%) and placebo (33%). However, only 5 patients dropped out of the study because of adverse effects (oxybutynin 2 and propantheline 3). No serious or lasting adverse effects were encountered with dryness of the mouth being the major complaint. Oxybutynin has statistically significant effects on subjective symptoms and objective urodynamic parameters in patients with detrusor hyperactivity compared to propantheline.

Subjective and clinical results after transurethral resection and suprapubic prostatectomy in benign prostatic hypertrophy

This study was performed after a mean postoperative period of approximately 2 years. Results after transurethral resection (TUR) appeared to be inferior to results after suprapubic prostatectomy in patients' subjective symptomatology concerning frequency, nocturia, urinary stream complaints and incontinence. Late postoperative complications were found in a greater extent after TUR. TUR showed more often pathologic uroflow and pathologic residual urine data. Generally speaking, the results after suprapubic prostatectomy were substantially more satisfactory than the results after TUR.

[Pathophysiology of primary renal pelvis outflow stenosis]

Ureteral peristalsis originates in the most proximal parts of the caliceal system. It is then conducted to the ureter by way of myogenic excitation conduction. In the pyeloureteral region, however, there seems to be some sort of physiological blockade and modulation of activity. It depends on the level of diuresis whether only a few or all contractions of the renal pelvis reach the ureter. Morphological and functional investigations show that the pathophysiological disturbance in cases of primary stenosis of the pyeloureteral junction seems to be a complete blockade of myogenic excitation conduction. The principle of open surgical corrections (dismembered pyeloureteroplasty) is not only to create a widely open connection between renal pelvis and ureter but also to remove the misfunctioning pyeloureteral segment and to substitute it by a region of improved myogenic excitation conduction.

[Pharmacologic modification of ureteral activity]

The renal pelvis and the ureter represent a functional system with myogenic excitation generation and conduction. The activity of this system is modulated by the autonomic nervous system: alpha-adrenergic and cholinergic substances stimulate, beta-adrenergic drugs inhibit the pyeloureteral activity. Besides the sympathetic nervous system with adrenergic postganglionic excitation conduction and the parasympathetic nervous system with cholinergic transmission, non-adrenergic, non-cholinergic systems appear to exist. Vasoactive intestinal peptide (VIP), e.g., markably decreases the frequency and amplitude of the ureteral activity. Calcium antagonists (e.g. nifedipin) lead to a direct inhibition of the ureteral activity: the quick phasic contractions are selectively oppressed without any influence on the tonic activity of the pyeloureter. A direct therapeutic modulation of the ureteral activity, however, e.g. to treat a colic or to accelerate the spontaneous discharge of stones, seems to be only rarely possible: Glucagone shows a markable decrease of ureteral peristalsis in animal experiments. Antagonists of prostaglandine proved to have not only an antiinflammatory and central analgetic effect but they also influence the pyeloureter directly by relaxing the muscular layer.

Uroflow measurements: their information yield in a long-term investigation of pre- and postoperative measurements

This investigation shows that the reproducibility of uroflow measurements is limited. For their evaluation, anamnesis and the measured results have to be taken into account equally. We found correspondence of both parameters in about 50% only. One single measurement cannot provide precise information, as psychogenic, social, and other factors influence the measurement. In our study 3 subjects had their micturitions registered over a period of 2 months. We found an increase of the maximum flow with increasing bladder volume. The maximum bladder volume was reached in only four micturitions. Normal values range at about 25% of the maximum bladder volume. Analyzing the micturitions in regard to the time of day, we found maximum flow rates in the morning hours. Under clinical conditions the altered surroundings lead to a measured result which is psychogenically influenced and can only be balanced after repeated measurements. The curves of all 3 patients were equal and inconspicuous. In cases of infravesical obstruction, surgical success could be documented by comparing the pre- and postoperative uroflows. In all cases of neurogenic bladder disorders and unclear findings, uroflow measurements are, however, not sufficient, and diagnosis is accomplished by a complete urodynamic examination. In spite of certain restrictions, uroflowmetry yields a high level of information, besides being a simple, at any time reproducible, and noninvasive procedure. Due to its low costs, it should be the primary step in diagnostics in the clinic as well as for practitioners.

[Radiological findings in bilharziasis of the urinary tract]

Bilharzia of the urinary tract has characteristic radiological changes; because of the increase in this disease, it is important to be familiar with these. The typical changes are demonstrated in six patients and could be seen on abdominal films, tomography of the pelvis, excretion urography and computed tomography. The paper is supplemented by a description of the area in which the disease is endemic.

Pacemaker process of ureteral peristalsis in multicalyceal kidneys

The mechanical activity of isolated strips from different areas of the pyeloureteral system was investigated in 10 pigs: calyx, renal pelvis, pyeloureteral junction and ureter. Additionally, electrical activity was measured in some pyeloureteral preparations using the sucrose-gap technique. Regular spontaneous activity with an average frequency of 9.5/min was recorded in calyceal strips, decreasing to 5.4/min in renal pelvis, 5.7/min in pyeloureteral preparations and to 1.2/min in ureteral preparations. The activity of renal pelvis, pyeloureteral and ureteral preparations was less regular, and bursts of fast activity (near 10/min) could be observed in all these preparations. The membrane potential of pyeloureteral strips showed spontaneous generator oscillations of about 10/min. Variations in the pattern of ureteral peristalsis are due to different coupling ratios of membrane potential oscillations to contractions. Adrenaline (10(-5) mol/l) increased the frequency of the oscillations and enhanced their manifestation in the mechanical recordings, whereas tetraethylammonium (5-20 mmol/l) only increased the coupling ratio. The following concept for the generation of ureteral peristalsis in multicalyceal kidneys is developed: several (primary) oscillators exist in the calyces; in the pyeloureteral junction a (secondary) pacemaker exists which has an intrinsic frequency similar to that of the calyceal pacemakers; both processes cooperate in the generation of ureteral peristalsis.

A tonic component in the motility of the upper urinary tract (renal pelvis-ureter)

In isolated muscle strips of porcine renal pelvis and ureter, the calcium antagonist nifedipine (3.10(-7) moles/l) completely suppressed spontaneous phasic mechanical activity and the phasic components of an adrenaline-induced activation (P-component). In the presence of nifedipine, adrenaline induced in pelvis preparations (but not in the ureter) a tonic contraction (T-component) which was on average 61% of the control reaction (SD +/- 26%; n = 35).

Pacemaker localization in the renal pelvis of the unicalyceal kidney. In vitro study in the rabbit

To determine the precise localization of the pacemaker in the renal pelvis of the unicalyceal rabbit kidney, the spontaneous activity of muscle strip preparations was investigated in vitro. (1) The highest frequency of spontaneous contractions was found in the most intrarenal part of the renal pelvis. (2) The frequency diminished from the most intrarenal parts to the pyeloureteral junction. (3) No spontaneous activity was observed in ureter preparations; even adrenaline, noradrenaline, acetylcholine and oxytocin did not start any contraction. In the pyeloureteral system the cells with the highest spontaneous frequency will act as a pacemaker. Cells with a less frequent activity can only work as secondary or latent pacemakers.

Effects of beta-adrenergic stimulating and blocking agents on the dynamics of the human bladder outlet

The alpha-adrenergic innervation of the functional urethra is a well-known fact, while beta-adrenergic influence is rather unknown until now. We studied the influence of beta-stimulating and beta-blocking agents on the human urethra by the urethral pressure profile (UPP). A decrease of the UPP under orciprenaline sulfate and an increase under propranolol could be mentioned.