Proof-of-Principle Experiment for Testing Strong-Field Quantum Electrodynamics with Exotic Atoms: High Precision X-Ray Spectroscopy of Muonic Neon

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst)  eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.

Measurements of Strong-Interaction Effects in Kaonic-Helium Isotopes at Sub-eV Precision with X-Ray Microcalorimeters

We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst)  eV and 6463.7±0.3(stat)±0.1(syst)  eV, and widths to be 2.5±1.0(stat)±0.4(syst)  eV and 1.0±0.6(stat)±0.3(stat)  eV, for kaonic ^{3}He and ^{4}He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.

Energy Calibration of Nonlinear Microcalorimeters with Uncertainty Estimates from Gaussian Process Regression

The nonlinear energy response of cryogenic microcalorimeters is usually corrected through an empirical calibration. X-ray or gamma-ray emission lines of known shape and energy anchor a smooth function that generalizes the calibration data and converts detector measurements to energies. We argue that this function should be an approximating spline. The theory of Gaussian process regression makes a case for this functional form. It also provides an important benefit previously absent from our calibration method: a quantitative uncertainty estimate for the calibrated energies, with lower uncertainty near the best-constrained calibration points.

Deexcitation Dynamics of Muonic Atoms Revealed by High-Precision Spectroscopy of Electronic K X Rays

We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kβ x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.

Undenatured type II collagen mitigates inflammation and cartilage degeneration in healthy Labrador Retrievers during an exercise regimen

The aim of this experiment was to evaluate the effect of undenatured type II collagen supplementation on inflammation and cartilage degeneration after exercise in healthy dogs. Forty healthy Labrador Retrievers (20 male/20 female; range 5-12 yr; average 8 yr) were sorted into two groups: undenatured type II collagen group receiving 40 mg UC-II (10 mg collagen type II/min. 3% undenatured type II collagen; Lonza Consumer Health, Inc.) and placebo group receiving 40 mg maltodextrin daily by capsule. After 2-wk loading, all dogs began an 11-wk endurance exercise regimen consisting of two weekly runs, starting at 5 km and increasing incrementally to 8 km, with one final 16 km run. Blood samples were collected at baseline, pre and post first 5 km run, and pre- and post-16 km run. Activity per kilometer was greater in male undenatured type II collagen vs. male placebo over all runs (P = 0.004), and average moving speed was greater in all undenatured type II collagen dogs compared with placebo over all runs (P < 0.001). Hematology analysis indicated that during the first insult, undenatured type II collagen dogs had a greater lymphocyte count (P < 0.001) and lymphocyte percentage (P = 0.001) vs. placebo dogs. Undenatured type II collagen dogs had a lesser neutrophil percentage (P = 0.042) and neutrophil to lymphocyte ratios (P = 0.001) compared to placebo dogs. For the final insult, undenatured type II collagen dogs had greater lymphocyte percentage (P = 0.013) and lesser mean corpuscular hemoglobin concentration (P = 0.043) compared with placebo dogs. Both groups had significant changes between timepoints for several hematological parameters. Biomarker IL-6 was lesser in undenatured type II collagen dogs compared with placebo at post 5 km (P = 0.037). Cartilage oligomeric matrix protein (COMP) was lesser in undenatured type II collagen dogs at post 16 km (P = 0.023), and only the placebo dogs had a significant increase in COMP from pre to post 16 km (P = 0.021). In summary, Labrador Retrievers supplemented with undenatured type II collagen had decreased inflammation and cartilage degeneration compared with nonsupplemented dogs during exercise.

Absolute energies and emission line shapes of the L x-ray transitions of lanthanide metals

We use an array of transition-edge sensors, cryogenic microcalorimeters with 4 eV energy resolution, to measure L x-ray emission-line profiles of four elements of the lanthanide series: praseodymium, neodymium, terbium, and holmium. The spectrometer also surveys numerous x-ray standards in order to establish an absolute-energy calibration traceable to the international system of units for the energy range 4 keV to 10 keV. The new results include emission line profiles for 97 lines, each expressed as a sum of one or more Voigt functions; improved absolute energy uncertainty on 71 of these lines relative to existing reference data; a median uncertainty on the peak energy of 0.24 eV, four to ten times better than the median of prior work; and six lines that lack any measured values in existing reference tables. The 97 lines comprise nearly all of the most intense L lines from these elements under broad-band x-ray excitation. The work improves on previous measurements made with a similar cryogenic spectrometer by the use of sensors with better linearity in the absorbed energy and a gold x-ray absorbing layer that has a Gaussian energy-response function. It also employs a novel sample holder that enables rapid switching between science targets and calibration targets with excellent gain balancing. Most of the results for peak energy values shown here should be considered as replacements for the currently tabulated standard reference values, while the line shapes given here represent a significant expansion of the scope of available reference data.

A transition-edge sensor-based x-ray spectrometer for the study of highly charged ions at the National Institute of Standards and Technology electron beam ion trap

We report on the design, commissioning, and initial measurements of a Transition-Edge Sensor (TES) x-ray spectrometer for the Electron Beam Ion Trap (EBIT) at the National Institute of Standards and Technology (NIST). Over the past few decades, the NIST EBIT has produced numerous studies of highly charged ions in diverse fields such as atomic physics, plasma spectroscopy, and laboratory astrophysics. The newly commissioned NIST EBIT TES Spectrometer (NETS) improves the measurement capabilities of the EBIT through a combination of high x-ray collection efficiency and resolving power. NETS utilizes 192 individual TES x-ray microcalorimeters (166/192 yield) to improve upon the collection area by a factor of ∼30 over the 4-pixel neutron transmutation doped germanium-based microcalorimeter spectrometer previously used at the NIST EBIT. The NETS microcalorimeters are optimized for the x-ray energies from roughly 500 eV to 8000 eV and achieve an energy resolution of 3.7 eV-5.0 eV over this range, a more modest (<2×) improvement over the previous microcalorimeters. Beyond this energy range, NETS can operate with various trade-offs, the most significant of which are reduced efficiency at lower energies and being limited to a subset of the pixels at higher energies. As an initial demonstration of the capabilities of NETS, we measured transitions in He-like and H-like O, Ne, and Ar as well as Ni-like W. We detail the energy calibration and data analysis techniques used to transform detector counts into x-ray spectra, a process that will be the basis for analyzing future data.

Demonstration of Athena X-IFU Compatible 40-Row Time-Division-Multiplexed Readout

Time-division multiplexing (TDM) is the backup readout technology for the X-ray Integral Field Unit (X-IFU), a 3,168-pixel X-ray transition-edge sensor (TES) array that will provide imaging spectroscopy for ESA's Athena satellite mission. X-0IFU design studies are considering readout with a multiplexing factor of up to 40. We present data showing 40-row TDM readout (32 TES rows + 8 repeats of the last row) of TESs that are of the same type as those being planned for X-IFU, using measurement and analysis parameters within the ranges specified for X-IFU. Singlecolumn TDM measurements have best-fit energy resolution of (1.91 ± 0.01) eV for the Al Kα complex (1.5 keV), (2.10 ± 0.02) eV for Ti Kα (4.5 keV), (2.23 ± 0.02) eV for Mn Kα (5.9 keV), (2.40 ± 0.02) eV for Co Kα (6.9 keV), and (3.44 ± 0.04) eV for Br Kα (11.9 keV). Three-column measurements have best-fit resolution of (2.03 ± 0.01) eV for Ti Kα and (2.40 ± 0.01) eV for Co Kα. The degradation due to the multiplexed readout ranges from 0.1 eV at the lower end of the energy range to 0.5 eV at the higher end. The demonstrated performance meets X-IFU's energy-resolution and energy-range requirements. True 40-row TDM readout, without repeated rows, of kilopixel scale arrays of X-IFU-like TESs is now under development.

Optimization of Time- and Code-Division-Multiplexed Readout for Athena X-IFU

Readout of a large, spacecraft-based array of superconducting transition-edge sensors (TESs) requires careful management of the layout area and power dissipation of the cryogenic-circuit components. We present three optimizations of our time- (TDM) and code-division-multiplexing (CDM) systems for the X-ray Integral Field Unit (X-IFU), a several-thousand-pixel-TES array for the planned Athena-satellite mission. The first optimization is a new readout scheme that is a hybrid of CDM and TDM. This C/TDM architecture balances CDM's noise advantage with TDM's layout compactness. The second is a redesign of a component: the shunt resistor that provides a dc-voltage bias to the TESs. A new layout and a thicker Pd-Au resistive layer combine to reduce this resistor's area by more than a factor of 5. Third, we have studied the power dissipated by the first-stage SQUIDs (superconducting quantum-interference devices) and the readout noise versus the critical current of the first-stage SqUIDs. As a result, the X-IFU TDM and C/TDM SQUIDs will have a specified junction critical current of 5 μA. Based on these design optimizations and TDM experiments described by Durkin, et al. (these proceedings), TDM meets all requirements to be X-IFU's backup-readout option. Hybrid C/TDM is another viable option that could save spacecraft resources.

A Robust Principal Component Analysis for Outlier Identification in Messy Microcalorimeter Data

A principal component analysis (PCA) of clean microcalorimeter pulse records can be a first step beyond statistically optimal linear filtering of pulses toward a fully nonlinear analysis. For PCA to be practical on spectrometers with hundreds of sensors, an automated identification of clean pulses is required. Robust forms of PCA are the subject of active research in machine learning. We examine a version known as coherence pursuit that is simple and fast and well matched to the automatic identification of outlier records, as needed for microcalorimeter pulse analysis.

A practical superconducting-microcalorimeter X-ray spectrometer for beamline and laboratory science

We describe a series of microcalorimeter X-ray spectrometers designed for a broad suite of measurement applications. The chief advantage of this type of spectrometer is that it can be orders of magnitude more efficient at collecting X-rays than more traditional high-resolution spectrometers that rely on wavelength-dispersive techniques. This advantage is most useful in applications that are traditionally photon-starved and/or involve radiation-sensitive samples. Each energy-dispersive spectrometer is built around an array of several hundred transition-edge sensors (TESs). TESs are superconducting thin films that are biased into their superconducting-to-normal-metal transitions. The spectrometers share a common readout architecture and many design elements, such as a compact, 65 mK detector package, 8-column time-division-multiplexed superconducting quantum-interference device readout, and a liquid-cryogen-free cryogenic system that is a two-stage adiabatic-demagnetization refrigerator backed by a pulse-tube cryocooler. We have adapted this flexible architecture to mate to a variety of sample chambers and measurement systems that encompass a range of observing geometries. There are two different types of TES pixels employed. The first, designed for X-ray energies below 10 keV, has a best demonstrated energy resolution of 2.1 eV (full-width-at-half-maximum or FWHM) at 5.9 keV. The second, designed for X-ray energies below 2 keV, has a best demonstrated resolution of 1.0 eV (FWHM) at 500 eV. Our team has now deployed seven of these X-ray spectrometers to a variety of light sources, accelerator facilities, and laboratory-scale experiments; these seven spectrometers have already performed measurements related to their applications. Another five of these spectrometers will come online in the near future. We have applied our TES spectrometers to the following measurement applications: synchrotron-based absorption and emission spectroscopy and energy-resolved scattering; accelerator-based spectroscopy of hadronic atoms and particle-induced-emission spectroscopy; laboratory-based time-resolved absorption and emission spectroscopy with a tabletop, broadband source; and laboratory-based metrology of X-ray-emission lines. Here, we discuss the design, construction, and operation of our TES spectrometers and show first-light measurements from the various systems. Finally, because X-ray-TES technology continues to mature, we discuss improvements to array size, energy resolution, and counting speed that we anticipate in our next generation of TES-X-ray spectrometers and beyond.

The Practice of Pulse Processing

The analysis of data from x-ray microcalorimeters requires great care; their excellent intrinsic energy resolution cannot usually be achieved in practice without a statistically near-optimal pulse analysis and corrections for important systematic errors. We describe the essential parts of a pulse-analysis pipeline for data from x-ray microcalorimeters, including steps taken to reduce systematic gain variation and the unwelcome dependence of filtered pulse heights on the exact pulse-arrival time. We find these steps collectively to be essential tools for getting the best results from a microcalorimeter-based x-ray spectrometer.

High-resolution X-ray emission spectroscopy with transition-edge sensors: present performance and future potential

X-ray emission spectroscopy (XES) is a powerful element-selective tool to analyze the oxidation states of atoms in complex compounds, determine their electronic configuration, and identify unknown compounds in challenging environments. Until now the low efficiency of wavelength-dispersive X-ray spectrometer technology has limited the use of XES, especially in combination with weaker laboratory X-ray sources. More efficient energy-dispersive detectors have either insufficient energy resolution because of the statistical limits described by Fano or too low counting rates to be of practical use. This paper updates an approach to high-resolution X-ray emission spectroscopy that uses a microcalorimeter detector array of superconducting transition-edge sensors (TESs). TES arrays are discussed and compared with conventional methods, and shown under which circumstances they are superior. It is also shown that a TES array can be integrated into a table-top time-resolved X-ray source and a soft X-ray synchrotron beamline to perform emission spectroscopy with good chemical sensitivity over a very wide range of energies.

Note: Operation of gamma-ray microcalorimeters at elevated count rates using filters with constraints

Microcalorimeter sensors operated near 0.1 K can measure the energy of individual x- and gamma-ray photons with significantly more precision than conventional semiconductor technologies. Both microcalorimeter arrays and higher per pixel count rates are desirable to increase the total throughput of spectrometers based on these devices. The millisecond recovery time of gamma-ray microcalorimeters and the resulting pulse pileup are significant obstacles to high per pixel count rates. Here, we demonstrate operation of a microcalorimeter detector at elevated count rates by use of convolution filters designed to be orthogonal to the exponential tail of a preceding pulse. These filters allow operation at 50% higher count rates than conventional filters while largely preserving sensor energy resolution.

Table-top ultrafast x-ray microcalorimeter spectrometry for molecular structure

This work presents an x-ray absorption measurement by use of ionizing radiation generated by a femtosecond pulsed laser source. The spectrometer was a microcalorimetric array whose pixels are capable of accurately measuring energies of individual radiation quanta. An isotropic continuum x-ray spectrum in the few-keV range was generated from a laser plasma source with a water-jet target. X rays were transmitted through a ferrocene powder sample to the detector, whose pixels have average photon energy resolution ΔE=3.14  eV full-width-at-half-maximum at 5.9 keV. The bond distance of ferrocene was retrieved from this first hard-x-ray absorption fine-structure spectrum collected with an energy-dispersive detector. This technique will be broadly enabling for time-resolved observations of structural dynamics in photoactive systems.

A high resolution gamma-ray spectrometer based on superconducting microcalorimeters

Improvements in superconductor device fabrication, detector hybridization techniques, and superconducting quantum interference device readout have made square-centimeter-sized arrays of gamma-ray microcalorimeters, based on transition-edge sensors (TESs), possible. At these collecting areas, gamma microcalorimeters can utilize their unprecedented energy resolution to perform spectroscopy in a number of applications that are limited by closely-spaced spectral peaks, for example, the nondestructive analysis of nuclear materials. We have built a 256 pixel spectrometer with an average full-width-at-half-maximum energy resolution of 53 eV at 97 keV, a useable dynamic range above 400 keV, and a collecting area of 5 cm(2). We have demonstrated multiplexed readout of the full 256 pixel array with 236 of the pixels (91%) giving spectroscopic data. This is the largest multiplexed array of TES microcalorimeters to date. This paper will review the spectrometer, highlighting the instrument design, detector fabrication, readout, operation of the instrument, and data processing. Further, we describe the characterization and performance of the newest 256 pixel array.

A simulation model for policy decision analysis: a case of pandemic influenza on a university campus

Pandemic influenza preparedness plans strongly focus on efficient mitigation strategies including social distancing, logistics and medical response. These strategies are formed by multiple decision makers before a pandemic outbreak and during the pandemic in local communities, states and nation-wide. In this paper, we model the spread of pandemic influenza in a local community, a university, and evaluate the mitigation policies. Since the development of an appropriate vaccine requires a significant amount of time and available antiviral quantities can only cover a relatively small proportion of the population, university decision makers will first focus on non-pharmaceutical interventions. These interventions include social distancing and isolation. The disease spread is modelled as differential equations-based compartmental model. The system is simulated for multiple non-pharmaceutical interventions such as social distancing including suspending university operations, evacuating dorms and isolation of infected individuals on campus. Although the model is built based on the preparedness plan of one of the biggest universities in the world, Arizona State University, it can easily be generalized for other colleges and universities. The policies and the decisions are tested by several simulation runs and evaluations of the mitigation strategies are presented in the paper.

Optical design of the atacama cosmology telescope and the millimeter bolometric array camera

The Atacama Cosmology Telescope is a 6 m telescope designed to map the cosmic microwave background simultaneously at 145, 215, and 280 GHz with arcminute resolution. Each frequency will have a 32 by 32 element focal plane array of transition edge sensor bolometers. The telescope and the cold reimaging optics are optimized for millimeter-wave observations with these sensitive detectors. The design of each is described.

Evidence for changing of cosmic ray composition between 10(17) and 10(18) eV from multicomponent measurements

The average mass composition of cosmic rays with primary energies between 10(17) and 10(18) eV has been studied using a hybrid detector consisting of the High Resolution Fly's Eye (HiRes) prototype and the MIA muon array. Measurements have been made of the change in the depth of shower maximum and the muon density as a function of energy. The results show that the composition is changing from a heavy to lighter mix as the energy increases.

Radical radiotherapy for localized adenocarcinoma of the prostate. A report of 191 cases

OBJECTIVE

To assess the results of radiotherapy in the treatment of localized prostate cancer. End points for assessment were survival, local control, development of metastases, and the toxicity of therapy.

MATERIALS AND METHODS

The case notes of 191 patients who were treated with radical radiotherapy between 1982 and 1992 were reviewed. The pathology of 130 patients was reviewed by a single pathologist. A multivariate analysis was performed to identify significant prognostic factors with regard to survival and relapse.

RESULTS

One-hundred and eighty-two patients were assessable. The minimum length of follow-up was one year (median = 40 months). The actuarial cause-specific 5 and 10 year survival rates were 63% and 35% respectively. Local progression occurred in 41% of patients with 37% developing metastases. Multivariate statistical analysis demonstrated that T stage and Gleason Score were significant predictors for survival. Late complications were usually mild, with only 4% developing serious bladder toxicity.

CONCLUSION

Radical radiotherapy has a role in the curative treatment of prostate cancer. Survival is significantly related to T stage at the time of presentation, and to the Gleason Score of the tumour. Survival in this series was not as good as the best surgical series, but it is still not clear which patients should receive radiotherapy and which surgery as their primary management.

Laparoscopic pelvic lymphadenectomy--early results

OBJECTIVE

To report our initial experience and early results of laparoscopic pelvic lymphadenectomy (LPL).

PATIENTS AND METHODS

Between May 1991 and April 1992, 10 patients with genitourinary malignancy (eight prostate, one bladder carcinoma, one penile melanoma) underwent LPL. Following biopsy, initial staging was carried out using computed tomography (CT), a bone scan and the prostate specific antigen level (prostate cancer). Six patients underwent unilateral laparoscopic dissection, three patients bilateral dissection and one patient required conversion to an open procedure. Operative times ranged from 2 to 3 h, and the number of lymph nodes removed ranged from three to nine (median five).

RESULTS

Three patients had their staging altered following LPL (one patient was upstaged and two patients were downstaged), with significant therapeutic implications. Two patients suffered thromboembolic complications while undergoing definitive therapy soon after LPL.

CONCLUSION

Our early results suggest that LPL is valuable in identifying suitable patients for radical therapy as well as excluding patients with lymph node involvement, thereby reducing morbidity.

Suppurative epididymo-orchitis in young "high risk" patients--a new problem?

During a 4-year period we have treated 3 young patients with severe epididymo-orchitis which progressed to suppuration (despite treatment with a range of antibiotics) and necessitated orchiectomy. All gave a history of "high risk" activity (2 homosexual, 1 sexual partner of intravenous drug user). One patient was suffering from acquired immune deficiency syndrome and another presented during seroconversion to HIV-positive status. Cytomegalovirus was the infective organism in one patient, but the pathogenesis in the others remains obscure. Investigations for atypical pathogens should be performed when young patients present with refractory epididymo-orchitis. These patients should also be counselled with regard to HIV testing.

Management of localised prostatic carcinoma

Localised carcinoma of the prostate may be amenable to radical curative therapy. Staging pelvic lymphadenectomy is controversial but is the only means of demonstrating lymph node spread accurately. Five patients in a group of 16 who presented apparently with localised prostatic carcinoma, and who had negative bone scan and CT scan, were shown at operation to have metastatic carcinoma involving their lymph nodes; 3 of 8 patients with high grade tumours were free of lymph node metastases. Without staging lymphadenectomy, these patients may have been inappropriately treated.

Videourodynamic assessment of the Stamey procedure for stress incontinence

Fifty-three patients underwent the Stamey procedure after stress incontinence was demonstrated by videourodynamic assessment. It was possible to repeat this assessment in 45 patients post-operatively; 58% were shown to be continent and in 20% the leakage was less. Failed operations were unrelated to age, weight, parity, degree of bladder neck descent or previous pelvic surgery. Coexisting detrusor instability was not a contraindication to surgery. Delayed voiding was common immediately after surgery but voiding problems were not encountered once micturition had been re-established. Although a significant objective failure rate was demonstrated, the Stamey procedure has many advantages and it can be recommended as first-line treatment in cases of stress incontinence.

Peritoneal flap ureteropexy for idiopathic retroperitoneal fibrosis

Eight patients had 13 ureters treated by peritoneal flap ureteropexy. There were no significant post-operative complications. Eleven ureters were functioning normally after an average follow-up of 28 months. The operation is suggested as a method of choice where omental wrapping is not possible.

Results of surgery following radical radiotherapy for invasive bladder cancer

Five hundred and ninety-one of 889 patients with T1 to T4 transitional cell carcinoma of the bladder had persistent or recurrent cancer after radical radiotherapy. Durable local control was significantly poorer for patients with grade 1 or T4 cancer before radiotherapy. Three hundred and twenty-two patients received additional surgical treatment: 211 were endoscopically managed and 111 had secondary cystectomy. The survival of patients with residual or recurrent cancer after radiotherapy was significantly improved by secondary local treatment (P less than 0.0001). A comparison was made between endoscopic treatment and cystectomy after radiotherapy. Patients having secondary cystectomy were younger (mean age 60.0 years) than those managed endoscopically (66.8 years). The 5-year actuarial survival rate (from the date of radiotherapy) for patients who had endoscopic treatment was 47.1% compared with 62.5% for those who had cystectomy (P = 0.16). After both treatments survival was significantly correlated with the T category of the tumour before radiotherapy. Local tumour control was better after cystectomy; 85.6% of patients were locally tumour-free at the end of follow-up compared with 44.5% of those managed endoscopically. There was no overall difference in the subsequent risk of metastases between the two forms of surgery. However, seven of 12 patients managed endoscopically prior to secondary cystectomy died of their cancer. Five of these patients died from metastases even though they were locally disease-free. There was a significantly increased risk of metastases in patients managed endoscopically who were not locally disease-free after treatment (P = 0.0003). Caution is advised in persisting with endoscopic treatment after radiotherapy if local control is not readily achieved.

Diagnosis and treatment of posterior urethral injury

The initial investigation and diagnosis in 28 patients with posterior urethral trauma are presented. Twenty-five patients underwent either primary realignment for complete rupture or cystostomy alone for partial rupture. The results of their management are reported.

Urethral dysplasia and bladder cancer in cystectomy specimens

Sixty-five patients had a cystectomy for a solitary bladder tumour (28) or multifocal lesions (37). The histological extent of the disease within the bladder was correlated with mucosal abnormalities within the urethra. The presence of multifocal or solitary bladder disease was not an accurate predictor of the presence or absence of urethral dysplasia. Details of mortality and morbidity associated with one-stage cysto-urethrectomy are presented and it is concluded that irrespective of whether the bladder contains a solitary or multifocal tumour, complete cysto-urethrectomy should be considered as the treatment of choice whenever cystectomy for attempted cure is indicated.

The control of male stress incontinence by implantable prostheses

Twenty-six patients were treated by implantable prostheses in a 10-year period, 22 by primary Kaufman III and four by primary Rosen. Sixteen of 22 patients having the Kaufman III procedure were cured or markedly improved over a follow-up period of 6 months to 10 years. The Rosen prosthesis, whilst simple to install and making the patient continent, eventually produced urethral fistulae in all cases. The Kaufman III prosthesis appears to be the procedure of choice in uncomplicated male stress incontinence.

Histopathological review of transitional cell carcinoma of the upper urinary tract

A histopathological review of 30 patients with transitional cell carcinoma (TCC) of the upper urinary tract showed that 21 patients had dysplastic epithelium adjacent to the tumour, irrespective of the degree of invasion; 20 patients had multifocal disease with some degree of dysplasia or carcinoma elsewhere. It is concluded that radical surgery should be performed whenever possible, even in the superficial low grade tumour.

The effects of radiotherapy on the integrity of the ureteroileal segment following cystectomy

Thirty-nine patients treated by cystectomy and ileal loop diversion for carcinoma of bladder were divided into 3 groups: A. cystectomy alone, B. cystectomy combined with pre-operative irradiation, C. Salvage cystectomy following radical radiotherapy. The post-operative complications and subsequent function of the ureteroileal segment of the urinary diversion were compared in the 3 groups. Those having primary cystectomy had the fewest complications and best long-term function, whilst those having surgery within 12 months of radical radiotherapy had the highest incidence of ureteroileal obstruction. The possible aetiology is discussed.

Incidence of urethral stricture after transurethral resection of prostate. Effects of urinary infection, urethral flora, and catheter material and size

Urethral stricture is the most common complication of transurethral resection of prostate, occurring in up to 29 per cent of cases. A prospective trial was initiated to ascertain if the presence of positive urine and urethral bacterial cultures made any significant difference in urethral stricture incidence. One hundred patients were entered in the trial, 50 receiving latex catheters and 50 receiving Teflon catheters. There was no significant difference between the two groups in incidence of urethral stricture, and there was no correlation between positive urine and urethral bacterial cultures and stricture formation. It is suggested, therefore, tha urethral catheter material and size and the presence of organisms in the urine and in the urethra do not contribute significantly to the formation of urethral stricture following transurethral resection of the prostate.

Radical nephrectomy--an assessment of morbidity, local control of disease and its effect on prognosis

Radical nephrectomy has a morbidity and mortality similar to that of the more simple procedure. Local control of disease may be obtained safely even in those patients with gross venous extension and worthwhile survival may be obtained in this group of patients. Further study of this extended operation would appear desirable.

Complete and incomplete forms of Beckwith-Wiedemann syndrome: their oncogenic potential

The diagnosis of Beckwith-Wiedemann syndrome may be missed because of variable or incomplete clinical expression. Recognition of such patients is important, however, because they have the potential for development of neoplasia. It seems likely that BWS and the congenital asymmetry-abdominal malignancy syndrome are at either end of the same spectrum, and that intermediate forms are the connecting links.

The incidence and consequences of damage to the parasympathetic nerve supply to the bladder after abdominoperineal resection of the rectum for carcinoma

Fifty-one patients undergoing abdominoperineal resection of the rectum for carcinoma were studied with regard to bladder function after surgery. Fifty-nine per cent had motor denervation of the bladder due to tumour or operative damage to the pelvic parasympathetic nerves and this produced symptoms of incomplete bladder emptying requiring treatment in 90% of this group. The factors affecting the incidence of nerve damage were discussed. The long-term effect of parasympathetic nerve damage was investigated and the management is discussed.

Renography in the assessment of patients with uretero-sigmoid diversion

A comparison was made between the excretion urogram and the radio-isotope renogram in 35 patients with uretero-sigmoid anastomosis. A good correlation was obtained between the 2 tests in the presence of radiographic evidence of (a) hydronephrosis, (b) poor renal function and (c) absent function. Renographic evidence of mild impairment of secretory function and of delayed excretion was associated with a significant number of normal excretion urograms and in a few instances there was later progression to severe renal impairment or hydronephrosis. Hydro-ureter associated with a normal renogram carried a good functional prognosis. Renography is recommended in the long-term supervision of patients with uretero-sigmoid anastomosis.

Bladder function following abdominoperineal excision of the rectum for carcinoma

Denervation of the bladder was demonstrated in 8 of 28 patients following abdominoperineal excision of the rectum. It is suggested that routine postoperative bladder-function studies be performed to detect this complication and thus to enable suitable postoperative care and long-term follow-up to be undertaken.