Ocular radiation exposure is negligible in normal volume endourological practice

INTRODUCTION

The annual dose limit for radiation exposure to the eye has been reduced recently; the eye is widely recognised as one of the most radiosensitive tissues in the body. There is minimal good quality research as to the radiation dose that the eye receives during endourological surgery and this study aimed to address this.

METHODS

A prospective study was performed over an 8-month period at a single large teaching hospital in the UK. Three index procedures were included: ureteric stent insertion, ureteroscopy (URS) and percutaneous nephrolithotomy (PCNL). Surgeons wore a dosimeter on the glabella with fluoroscopy time (FT) and dose area product (DAP) recorded for each case.

RESULTS

A total of 404 procedures were included (247 URSs, 150 ureteric stent insertions and 7 PCNLs). Dosimeters were worn by ten surgeons. Mean FTs (URS 20.56s; ureteric stent 18.96s; PCNL 360.67s) and mean DAP (URS 100.82cGy/m2, ureteric stent 119.82cGy/m2 and PCNL 1121.62cGy/m2) were identified with significant intersurgeon variability. No surgeon had a total dosimeter dose >0.00mSv.

CONCLUSIONS

The International Commission on Radiological Protection recently reduced the yearly eye dose limit from 150 to 20mSv. Cataractogenesis is no longer considered a typical deterministic effect, with a threshold level below which no effect occurs. Even in higher volume centres, these annual limits are unlikely to be reached. Lead glasses may be considered for surgeons and radiologists with the highest exposure but, for the majority, ocular radiation exposure is negligible.

Artificial Intelligence-Assisted Automated Applicator Digitization for Fully-Automated Gynecological High-Dose Rate Brachytherapy Treatment Planning

PURPOSE/OBJECTIVE(S)

To automate the digitization of plastic and titanium applicators used in interstitial and hybrid gynecological (GYN) computed tomography (CT)-based high-dose-rate (HDR) brachytherapy procedures to accelerate the planning and reduce the potential for planning errors. Our hypothesis is that artificial intelligence can accurately automate the identification and digitization of plastic and titanium applicators used in HDR brachytherapy.

MATERIALS/METHODS

Forty-eight patients who had received GYN procedures (7 tandem/ring: plastic applicators, 41 interstitial: titanium needles) were selected retrospectively. Patients were randomly split into training (n = 40) and test (n = 8) sets for this study. DICOM images and digitized needles from delivered plans were converted to 3D binary format. The points from each needle were transformed to individual contours and combined into a single binary mask using custom software. Using nnU-Net, a self-configuring deep convolutional neural network, 2D and 3D U-Net architectures were trained and ensembled. With the CT image as input, the nnU-Net model learned features to automatically segment the needle contours. Lastly, a 3D U-Net model was trained using 5 of the 7 tandem/ring cases (plastic applicators), with two reserved to evaluate this automated digitization. The models' performance was evaluated using the Dice Similarity Coefficient (DSC) and identification rate for individual needles.

RESULTS

The model trained on 40 patients performed well on titanium needle cases [mean (+/- std. dev.) DSC = 0.738+/-0.034], but did not perform well on the tandem/ring cases [DSC = 0.408] in the test set. This model automatically identified 100% (54 out of 54) titanium needles but missed all plastic applicators from tandem/ring cases. Training a model with only a limited number of tandem/ring (plastic applicators) cases greatly improved segmentation accuracy [mean DSC = 0.646] for tandem/ring test cases. This model which was trained using only tandem/ring cases, automatically identified 7 out of 7 needles (100% vs 0% with previous model) from cases in the test set.

CONCLUSION

The nnU-Net can automatically detect HDR needles with high confidence. Using applicator-specific identification models may improve digitization accuracy. Further evaluation of these tools on larger datasets will confirm the findings of this study.

Grambank reveals the importance of genealogical constraints on linguistic diversity and highlights the impact of language loss

While global patterns of human genetic diversity are increasingly well characterized, the diversity of human languages remains less systematically described. Here, we outline the Grambank database. With over 400,000 data points and 2400 languages, Grambank is the largest comparative grammatical database available. The comprehensiveness of Grambank allows us to quantify the relative effects of genealogical inheritance and geographic proximity on the structural diversity of the world's languages, evaluate constraints on linguistic diversity, and identify the world's most unusual languages. An analysis of the consequences of language loss reveals that the reduction in diversity will be strikingly uneven across the major linguistic regions of the world. Without sustained efforts to document and revitalize endangered languages, our linguistic window into human history, cognition, and culture will be seriously fragmented.

Urological issues in cyclists

Cycle use has grown rapidly over the last few years in the UK. British Cycling membership has increased threefold since the 2012 Olympic and Paralympic Games, and this is likely to rise in the wake of the Coronavirus pandemic. As urologists, day-to-day encounters with cyclists are commonplace, who may present with acute traumatic injuries or chronic overuse injuries. The aim of this literature review was to evaluate the effect of cycling on conditions presenting to the urology clinic, in particular those of raised prostate-specific antigen (PSA), haematuria and soft-tissue lesions (‘cyclist nodules’). Furthermore, the review aimed to summarize the relationship between cycling and pudendal nerve entrapment (PNE) syndromes. A PubMed search of the literature on cycling and genitourinary disorders was performed. The literature suggests no significant change in PSA levels after a bout of cycling. Age appears to have no effect on the change in PSA experienced following a bout of cycling, in particular when comparing those <50 years of age to those >50 years of age. Haematuria appears to be rare with cycling but has been described, even with stationary bike riding. It is imperative to exclude coexisting urinary-tract pathological conditions, and cycling-induced haematuria should always be considered a diagnosis of exclusion. Perineal nodular induration (‘cyclist nodules’) is a rare condition, related to pressure and repetitive micro-trauma between the perineum and saddle. Pudendal Nerve Entrapment (PNE) represents the most common bicycling-associated urogenital complaint. Numbness in the perineum, penis, scrotum or buttocks—‘genital numbness’—is the most common and most recognized symptom of pudendal compression. Despite several studies demonstrating a link between elite cyclists and erectile dysfunction, for the average cyclist riding may actually have a protective effect on sexual function.

364 The Cycling Urologist: Effect on PSA, Haematuria, Pudendal Nerve Entrapment and Cyclists Nodules

Aim

Cycle use has vastly increased over the last few years in the UK. The aim of this review was to evaluate the effect of cycling on the common conditions presenting to the urology clinic, in particular those of raised PSA, haematuria, soft tissue lesions (“cyclist nodules”) and pudendal nerve entrapment syndromes.

Method

A PUBMED search of the literature on cycling and genitourinary disorders was performed. The keywords included “Bicycling” AND “Prostate-specific antigen”, “Bicycling” AND “Haematuria”, “Bicycling” AND “Cyclist Nodules”, “Bicycling” AND “Pudendal Nerve Entrapment”.

Results

The literature suggests no significant change in total PSA levels after a bout of cycling, regardless of age. The type of cycling (mountain biking vs. road cycling) does not influence PSA levels. It is possible that the saddle used in cycling may displace the pressure across the perineal and gluteal region to effectively alleviate pressure on the prostate. Haematuria appears to be rare with cycling but has been described. Perineal nodular induration is a very rare - although possibly under diagnosed condition. It is thought to be caused by repetitive micro trauma from contact between the perineum and saddle. Pudendal nerve entrapment (PNE) represents the most common bicycling associated urogenital problem. Numbness in the perineum, penis, scrotum or the buttocks is the most common and most recognised symptom. Genital numbness may occur unrelated to erectile dysfunction (ED) although cycling related ED is invariably associated with genital numbness.

Conclusions

Urology Trainees and Consultants should be aware of how recreational and high-level cycling may result in presentation to the Urology clinic.

Extracellular buffer choice influences acid-base responses and gastrointestinal symptoms

To compare the bicarbonate kinetics and gastrointestinal (GI) symptom responses between an equal dose of sodium bicarbonate and sodium citrate using delayed-release capsules. Thirteen active males (age 20.5 ± 2.1 y, height 1.8 ± 0.1 m and body mass [BM] 76.5 ± 9.6 kg) consumed either 0.3 g^.kg^-1 BM sodium bicarbonate, sodium citrate or a placebo, using a double-blind, randomized crossover design. Blood bicarbonate ion (HCO₃^-) concentration, pH and GI symptoms were measured pre-consumption and every 10 min for 180 min post-consumption. Blood HCO₃^- concentration (P < 0.001) and pH (P = 0.040) were significantly higher in the sodium bicarbonate condition compared with sodium citrate condition up to 3 h post-consumption. Peak blood HCO₃^- concentration was significantly higher with the sodium bicarbonate compared with citrate (P < 0.001). Mean GI symptom scores were lower (P = 0.037) for sodium citrate (1.5 ± 1.8 AU) than bicarbonate (2.6 ± 3.1 AU), with considerable inter-individual variability. No GI symptoms were reported following consumption of the placebo. Both substances increase HCO₃^- values significantly, with sodium bicarbonate causing significantly higher pH and HCO₃^- values than the same dose of sodium citrate, but results in slightly more severe GI symptoms.

Clinical and cost implications of using immediate MRI in the management of patients with a suspected scaphoid fracture and negative radiographs results from the SMaRT trial

AIMS

The aim of the Scaphoid Magnetic Resonance Imaging in Trauma (SMaRT) trial was to evaluate the clinical and cost implications of using immediate MRI in the acute management of patients with a suspected fracture of the scaphoid with negative radiographs.

PATIENTS AND METHODS

Patients who presented to the emergency department (ED) with a suspected fracture of the scaphoid and negative radiographs were randomized to a control group, who did not undergo further imaging in the ED, or an intervention group, who had an MRI of the wrist as an additional test during the initial ED attendance. Most participants were male (52% control, 61% intervention), with a mean age of 36.2 years (18 to 73) in the control group and 38.2 years (20 to 71) in the intervention group. The primary outcome was total cost impact at three months post-recruitment. Secondary outcomes included total costs at six months, the assessment of clinical findings, diagnostic accuracy, and the participants' self-reported level of satisfaction. Differences in cost were estimated using generalized linear models with gamma errors.

RESULTS

The mean cost up to three months post-recruitment per participant was £542.40 (sd £855.20, n = 65) for the control group and £368.40 (sd £338.60, n = 67) for the intervention group, leading to an estimated cost difference of £174 (95% confidence interval (CI) -£30 to £378; p = 0.094). The cost difference per participant increased to £266 (95% CI £3.30 to £528; p = 0.047) at six months. Overall, 6.2% of participants (4/65, control group) and 10.4% of participants (7/67, intervention group) had sustained a fracture of the scaphoid (p = 0.37). In addition, 7.7% of participants (5/65, control group) and 22.4% of participants (15/67, intervention group) had other fractures diagnosed (p = 0.019). The use of MRI was associated with higher diagnostic accuracy both in the diagnosis of a fracture of the scaphoid (100.0% vs 93.8%) and of any other fracture (98.5% vs 84.6%).

CONCLUSION

The use of immediate MRI in the management of participants with a suspected fracture of the scaphoid and negative radiographs led to cost savings while improving the pathway's diagnostic accuracy and patient satisfaction. Cite this article: Bone Joint J 2019;101-B:984-994.

Routine screening for pain combined with a pain treatment protocol in head and neck cancer: a randomised controlled trial

BACKGROUND

We compared the effectiveness and cost of a pain screening and treatment program, with usual care in head and neck cancer patients with significant pain.

METHODS

Patients were screened for the presence of pain and then randomly assigned to either an intervention group, consisting of a pain treatment protocol and an education program, or to usual care. Primary outcome was change in the Pain Severity Index (PSI) over three months.

RESULTS

We screened 1074 patients of whom 156 were randomized to either intervention or usual care. Mean PSI was reduced over three months in both groups, with no significant difference between the two groups. The Pain Management Index (PMI) at three months, was significantly improved in the intervention group compared with usual care (P<0.001), as was Patient Satisfaction (mean difference in scores was statistically significant: -0.30 [-0.60 to -0.15]). All subjects reported clinically significant levels of anxiety and depression throughout the study. Treatment costs were significantly higher for intervention (mean=£400) compared with usual care (£200), with a low likelihood of being cost-effective.

CONCLUSIONS

There was no difference in the Pain Severity Index between the two groups. However there were significant improvements in the intervention group in patient satisfaction and PMI. The pain screening process itself was effective. Sufficient benefit was demonstrated as a result of the intervention to allow continued development of pain treatment pathways, rather than allowing pain treatment to be left to nonformalised ad hoc arrangements.

Long-term decline of the Amazon carbon sink

Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

Magnetically driven middle ear ossicles for optical measurement of vibrations in an ear with opened tympanic membrane

Vibrations of the middle ear ossicles are easily measured by means of laser vibrometry. However, laser vibrometry requires free visual access to the object under investigation, and acquiring free visual access to the ossicles through the ear canal requires the removal of the tympanic membrane (TM), with the result that the ossicles can no longer be stimulated acoustically. To overcome this, we devised a new setup in which the ossicles can be driven magnetically. After measuring the response of the TM to an acoustic signal, we then remove it and attach a small magnet to the exposed manubrium (a part of the most lateral auditory ossicle, the malleus, which is normally attached to the TM). An electromagnetic excitation coil is then used to drive the magnet, and the output to the coil adjusted until the vibration of the manubrium, as measured by the vibrometer, matches that measured in response to the acoustic signal. Such a setup may have uses in research on middle ear mechanics, such as the measurement of nonlinearities in their response, as well as applications in the diagnosis of middle ear conditions such as the fixation of the ossicles by otosclerosis or in chronic otitis media. We describe our setup and discuss the viability of our method and its future clinical potential by presenting some measurements on an artificially fixated ear.

Use of a gentamicin-impregnated collagen sheet (Collatamp(®) ) following implantation of a sacral nerve stimulator for faecal incontinence

AIM

Gentamicin-impregnated collagen (Collatamp(®) ) is well described for the prevention of infection in surgery. This technical note describes its intraoperative use as a prophylactic measure to prevent infection following implantation of a sacral nerve stimulator for faecal incontinence.

METHOD

Following implantation of the Interstim II Neurostimulator (Medtronic Neuromodulation, 710 Medtronic Parkway, Minneapolis, USA) in a subcutaneous pocket overlying the gluteal muscle, a single sheet of 10cm × 10cm gentamicin-impregnated collagen is placed within the wound covering the implant. The subcutaneous tissue and skin are then closed in separate layers.

RESULTS

To date eight patients [median age 46.5 (30-59) years] have received prophylactic cover with gentamicin-impregnated collagen following permanent sacral nerve stimulator implantation. At a median interval of 89.5 (51-128) days, none of these patients developed a wound infection at the site of the neurostimulator implant.

CONCLUSION

Gentamicin-impregnated collagen (Collatamp(®) ) used in the implantation of a sacral nerve stimulator may be a useful addition to the technique.

Relation of exhaled nitric oxide levels to development of bronchopulmonary dysplasia

OBJECTIVE

To test the hypothesis that exhaled nitric oxide levels on day 28 and changes in exhaled nitric oxide levels in the neonatal period would differ according to whether infants developed bronchopulmonary dysplasia (BPD) and its severity.

DESIGN

Prospective observational study.

SETTING

Tertiary neonatal intensive care unit.

PATIENTS

80 infants (median gestational age 28, range 24-32 weeks), 46 of whom developed BPD.

INTERVENTIONS

Exhaled nitric oxide measurements were attempted on days 3, 5, 7, 14, 21 and 28.

MAIN OUTCOME MEASURES

BPD (oxygen dependency at 28 days), mild BPD (oxygen dependent at 28 days, but not 36 weeks postmenstrual age (PMA)); moderate BPD (oxygen dependent at 36 weeks PMA) and severe BPD (respiratory support dependent at 36 weeks PMA).

RESULTS

On day 28, exhaled nitric oxide levels were higher in infants with BPD compared to those without BPD (p<0.001) and there was a linear trend in exhaled nitric oxide results as BPD severity increased (p = 0.006). No significances in the change in exhaled nitric oxide levels over the neonatal period were found between the four groups.

CONCLUSION

Exhaled nitric oxide levels are raised in infants with established BPD, particularly in those developing moderate or severe BPD, and may reflect ongoing inflammation.

The effect of a c.-8G>T polymorphism on the expression of cytochrome b5A and boar taint in pigs

The level of cytochrome b5A (CYB5A) in pig testis is correlated with boar taint from androstenone and an AF016388:c.-8G>T polymorphism in CYB5A has been linked with low androstenone levels in the fat of pigs. In this study, we developed a polymerase chain reaction-based assay to genotype 1242 boars from eight lines for the c.-8G>T SNP. The c.-8T allele was found in all eight lines at a frequency ranging from 1.8% to 20.3% with an overall frequency of 8.6%. Significant deviations from Hardy-Weinberg equilibrium were found in the Hampshire, Landrace and Yorkshire breeds. The homozygous mutant c.-8TT occurred infrequently and was not found in some lines, but was consistently associated with low androstenone levels in fat. Both CYB5A mRNA and CYB5A protein levels were decreased in the c.-8TT genotype in a subset of Yorkshire boars, suggesting that low levels of CYB5A protein in the c.-8TT mutant were not due to inefficient translation of CYB5A mRNA. There were significant but modest marker effects on fat androstenone levels in Landrace, Yorkshire and a Large White/Duroc cross and fat skatole in Duroc and Sire Line breeds. There was no effect of CYB5A genotype on bulbourethral gland length, suggesting that this SNP will not affect reproductive traits. We conclude that the c.-8G>T SNP in the CYB5A gene has a significant but modest effect on boar taint in male pigs and could be useful in some breeds as part of a panel of SNP markers in a marker-assisted selection programme to produce low boar taint pigs.

Risk factors for respiratory morbidity in infancy after very premature birth

OBJECTIVES

To determine the occurrence of respiratory morbidity during infancy after very premature birth and to identify risk factors.

DESIGN

Prospective follow up study.

SETTING

The United Kingdom oscillation study.

PATIENTS

492 infants, all born before 29 weeks gestation.

INTERVENTIONS

Structured questionnaires were completed by local paediatricians when the infants were seen in outpatients at 6 and 12 months of age corrected for prematurity.

MAIN OUTCOME MEASURES

Cough, wheeze, and treatment requirements and the composite measure of respiratory morbidity (cough, frequent cough, cough without infection, wheeze, frequent wheeze, wheeze without infection, and use of chest medicine) and their relation to 13 possible explanatory variables.

RESULTS

At 6 and 12 months of corrected age, 27% of the infants coughed and 6% had frequent (more than once a week) cough, and 20% and 3% respectively had wheeze or frequent wheeze. At 6 and 12 months, 14% of infants had taken bronchodilators and 8% inhaled steroids. After adjustment for multiple outcome testing, four factors were associated with increased respiratory morbidity: male sex, oxygen dependency at 36 weeks postmenstrual age, having older siblings aged less than 5 years, and living in rented accommodation.

CONCLUSIONS

Male infants are particularly vulnerable to respiratory morbidity in infancy after very premature birth. It is important to identify a safe and effective strategy to prevent chronic oxygen dependency.