Impact of UV Radiation on the Raman Signal of Cystine: Implications for the Detection of S-rich Organics on Mars.

Traces of life may have been preserved in ancient martian rocks in the form of molecular fossils. Yet the surface of Mars is continuously exposed to intense UV radiation detrimental to the preservation of organics. Because the payload of the next rovers going to Mars to seek traces of life will comprise Raman spectroscopy tools, laboratory simulations that document the effect of UV radiation on the Raman signal of organics appear critically needed. The experiments conducted here evidence that UV radiation is directly responsible for the increase of disorder and for the creation of electronic defects and radicals within the molecular structure of S-rich organics such as cystine, enhancing the contribution of light diffusion processes to the Raman signal. The present results suggest that long exposure to UV radiation would ultimately be responsible for the total degradation of the Raman signal of cystine. Yet because the degradation induced by UV is not instantaneous, it should be possible to detect freshly excavated S-rich organics with the Raman instruments on board the rovers. Alternatively, given the very short lifetime of organic fluorescence (nanoseconds) compared to most mineral luminescence (micro- to milliseconds), exploiting fluorescence signals might allow the detection of S-rich organics on Mars. In any case, as illustrated here, we should not expect to detect pristine S-rich organic compounds on Mars, but rather by-products of their degradation.

Postoperative urinary retention: risk factors, bladder filling rate and time to catheterization: an observational study as part of a randomized controlled trial.

BACKGROUND: Knowledge of risk factors for postoperative urinary retention may guide appropriate and timely urinary catheterization. We aimed to determine independent risk factors for postoperative urinary catheterization in general surgical patients. In addition, we calculated bladder filling rate and assessed the time to spontaneous voiding or catheterization. We used the patients previously determined individual maximum bladder capacity as threshold for urinary catheterization. METHODS: Risk factors for urinary catheterization were prospectively determined in 936 general surgical patients. Patients were at least 18 years of age and operated under general or spinal anesthesia without the need for an indwelling urinary catheter. Patients measured their maximum bladder capacity preoperatively at home, by voiding in a calibrated bowl after a strong urge that could no longer be ignored. Postoperatively, bladder volumes were assessed hourly with ultrasound. When patients reached their maximum bladder capacity and were unable to void, they were catheterized by the nursing staff. Bladder filling rate and time to catheterization were determined. RESULTS: Spinal anesthesia was the main independent modifiable risk factor for urinary catheterization (hyperbaric bupivacaine, relative risk 8.1, articaine RR 3.1). Unmodifiable risk factors were a maximum bladder capacity < 500 mL (RR 6.7), duration of surgery ≥ 60 min (RR 5.5), first scanned bladder volume at the Post Anesthesia Care Unit ≥250mL (RR 2.1), and age ≥ 60 years (RR 2.0). Urine production varied from 100 to 200 mL/h. Catheterization or spontaneous voiding took place approximately 4 h postoperatively. CONCLUSION: Spinal anesthesia, longer surgery time, and older age are the main risk factors for urinary retention catheterization. Awareness of these risk factors, regularly bladder volume scanning (at least every 3 h) and using the individual maximum bladder capacity as volume threshold for urinary catheterization may avoid unnecessary urinary catheterization and will prevent bladder overdistention with the attendant risk of lower urinary tract injury. TRIAL REGISTRATION: Dutch Central Committee for Human Studies registered trial database: NL 21058.099.07. Current Controlled Trials database: Preventing Bladder Catheterization after an Operation under General or Spinal Anesthesia by Using the Patient's Own Maximum Bladder Capacity as a Limit for Maximum Bladder Volume. ISRCTN97786497 . Registered 18 July 2011 -Retrospectively registered. The original study started 19 May 2008, and ended 30 April 2009, when the last patient was included.

[Good urodynamic practice: consensus on the terminology].

In this publication a summary of the published manuscript "Good Urodynamic Practices and Terms 2016: Urodynamics, uroflowmetry, cystometry, and pressure-flow study" developed by a working group under the guidance of the Standardization Steering Committee of International Continence Society (ICS)1 is presented. The members of the working group were: Werner Schaefer, Gunnar Lose, Howard B. Goldman, Michael Guralnick, Sharon Eustice, Tamara Dickinson, Hashim Hashim and Peter F.W.M Rosier.

Adaptation to Spanish of the ICS Good Urodynamic Practices. / Adaptación al español de las Good Urodynamic Practices de la International Continence Society.

The standardisation working group of the International Continence Society has updated the Good Urodynamic Practice directives. This evidence-based ICS-GUP2016 has defined the terminology and standards of Urodynamic practice, for the laboratory and for individual practice, in quality control during cystometry and pressure-flow analysis. In addition, the working group included recommendations prior to the test and information about how to prepare the patient, as well as recommendations for the reporting of urodynamics. Based on earlier International Continence Society standardisations and current evidence, the practice of uroflowmetry, cystometry and pressure-flow study have been detailed with a view to ensuring that this Good Urodynamic Practice update contributes towards improving clinical and research quality in urodynamics.

Detection of atomic and molecular mega-electron-volt projectiles using an x-ray charged coupled device camera.

We show that an x-ray charge coupled device (CCD) may be used as a particle detector for atomic and molecular mega-electron-volt (MeV) projectiles of around a few hundred keV per atomic mass unit. For atomic species, spectroscopic properties in kinetic energy measurements (i.e., linearity and energy resolution) are found to be close to those currently obtained with implanted or surface barrier silicon particle detectors. For molecular species, in order to increase the maximum kinetic energy detection limit, we propose to put a thin foil in front of the CCD. This foil breaks up the molecules into atoms and spreads the charges over many CCD pixels and therefore avoiding saturation effects. This opens new perspectives in high velocity molecular dissociation studies with accelerator facilities.

[Guideline 'Delirium']. / Richtlijn 'Delirium'.

The Dutch Association of Psychiatry, together with the Dutch Association of Clinical Geriatrics and with methodological support from the Dutch Institute for Healthcare Improvement (CBO) has developed a guideline for the optimal diagnosis, treatment and prevention of delirium. Delirium is caused by somatic illness or the use of medication, drugs or alcohol. Delirium is common among the somatically ill admitted to a general hospital and is associated with increased morbidity and mortality. Important predisposing factors for delirium are: age > or =70 years, cognitive disturbances, sensory impairments, problems in daily activities, and the use of alcohol and opiates. Precipitating factors that may provoke delirium are: infection, fever, dehydration, serum electrolyte imbalance, polypharmacy, and the use of psychotropic medication, particularly anticholinergic drugs. Detection, diagnosis, and assessment of the severity of delirium are based on clinical examination, case history, observation, mental status examination including tests of cognitive function, and diagnosis of underlying somatic diseases. For daily practice, measurement tools are not necessary, nor are laboratory or imaging tests, such as electroencephalography. Haloperidol is the treatment of first choice for delirium due to somatic illness, except in patients with delirium due to drug use or medication, Parkinson's disease or Lewy body dementia. In cases of concurrent alcohol withdrawal syndrome, delirium may be treated with haloperidol and a benzodiazepine and B-vitamins. Medical and environmental interventions have been shown to reduce the incidence and duration of delirium.

[Guideline 'Chronic heart failure']. / Richtlijn 'Chronisch hartfalen'.

A new Dutch clinical practice guideline has been developed for the diagnosis, treatment and supportive care of patients with chronic heart failure. This has been formulated by a multidisciplinary working group, set up by the Netherlands Heart Foundation and the Netherlands Society of Cardiology, in cooperation with the Dutch Institute for Healthcare Improvement. Heart failure is defined as: 'a complex of complaints and symptoms resulting from an inadequate pumping function of the heart'. Indications for heart failure are dyspnoea on exertion, reduced exertion tolerance and oedema. By using data from the medical history, case history, physical examination and simple additional tests (laboratory tests, ECG, chest X-ray photos) it is possible to demonstrate or exclude heart failure in clear-cut cases. Doppler ultrasonography should be performed in all patients where heart failure is suspected but cannot be clearly demonstrated. The initial treatment for patients with heart failure with reduced systolic LV function generally consists of the administration of a thiazide or loop diuretic together with an angiotensin-converting enzyme inhibitor and a beta-blocker, to which digoxin and/or spironolactone may be added. For very old patients extra attention should be given to the comorbidity and the medication and dosing scheme should be as simple as possible. The worse the cardiac function, the more the salt and fluid intake should be limited and the more strictly the weight should be monitored.

Comparison of different computer models of the neural control system of the lower urinary tract.

This paper presents a series of five models that were formulated for describing the neural control of the lower urinary tract in humans. A parsimonious formulation of the effect of the sympathetic system, the pre-optic area, and urethral afferents on the simulated behavior are included. In spite of the relative simplicity of the five models studied, behavior that resembles normal lower urinary tract behavior as seen during an urodynamic investigation could be simulated. The models were tested by studying their response to disturbances of the afferent signal from the bladder. It was found that the inhibiting reflex that results from including the sympathetic system or the pre-optic area (PrOA) only counteracts the disturbance in the storage phase. Once micturition has started, these inhibiting reflexes are suppressed. A detrusor contraction that does not result in complete micturition similar to an unstable detrusor contraction could be simulated in a model including urethral afferents. Owing to the number of uncertainties in these models, so far no unambiguous explanation of normal and pathological lower urinary tract behavior can be given. However, these models can be used as an additional tool in studies of the mechanisms of the involved neural control.

A computer model for describing the effect of urethral afferents on simulated lower urinary tract function.

A computer model of mechanical properties of the bladder, the urethra and the rhabdosphincter, as well as their neural control is presented in this paper. The model has a rather simple design and processes sensory information from both the bladder wall tension and urethral stretch. It is assumed that afferent signals from the urethra are involved in a sacral excitatory reflex and a supraspinal inhibitory reflex. Pressure and flow signals that resemble experimentally measured normal human behaviour could be simulated with this model. From these simulations the relation between the neural control mechanisms used in the model and the neural control mechanism in vivo cannot be judged entirely because similar behaviour could be simulated with models that are bas ed on different neural control mechanisms. Also behaviour that resembles detrusor overactivity was simulated with our model after an externally induced rise in detrusor pressure was added. Detrusor overactivity, sometimes in combination with urethral relaxation, can occur during a urodynamic investigation. A possible explanation for this detrusor overactivity might be that the micturition reflex is triggered by unknown disturbances and is inhibited immediately after by the same mechanism that normally ceases voiding. The described model provides such a mechanism. Based on these simulations, therefore, it is concluded that urethral afferent signals might be important in lower urinary tract control.

Stroke following vertebral artery dissection: a case study.

Vertebral artery dissection is an extremely rare but serious precursor to stroke. A case study illustrates how accurate early assessment and diagnosis can permit prompt intervention. Favorable treatment outcomes can occur when such astute management takes place.

A computer model of the neural control of the lower urinary tract.

Better understanding of the underlying working mechanism of the neural control of the lower urinary tract will facilitate the treatment of dysfunction with a neurogenic cause. We developed a computer model to study the effect of a neural control system on lower urinary tract behavior. To model the mechanical properties and neural control, assumptions had to be made. These assumptions were based, as much as possible, on knowledge and hypotheses taken from the literature. With valid assumptions, it should be possible to simulate normal as well as pathological behavior. To test the computer model, first, normal behavior of the lower urinary tract was simulated, and secondly, the known features of bladder outlet obstruction were simulated after the properties of the urethra were changed. The simulation results are comparable with measured data, so the assumptions on which the model is based could be valid. If the assumptions are valid, the feedback loops used in the model are also important feedback loops in vivo, and the model can be used to gain insight into the underlying mechanism of neural control.

Brain and spinal cord abnormalities in multiple sclerosis. Correlation between MRI parameters, clinical subtypes and symptoms.

We investigated various magnetic resonance MRI parameters for both brain and spinal cord to see if any improved the clinicoradiological correlation in multiple sclerosis. Ninety-one multiple sclerosis patients (28 relapsing-remitting, 32 secondary progressive and 31 primary progressive) were imaged using conventional T1, proton density- and T2-weighted MRI of the brain and spinal cord. Focal brain and spinal cord lesion load was scored, as were diffuse signal abnormalities, brain ventricular volume and spinal cord cross-sectional area. Clinical measures included the expanded disability status scale (EDSS), the functional systems score and a dedicated urology complaint questionnaire. Secondary progressive patients differed from relapsing-remitting and primary progressive patients by a larger number of hypointense T1 lesions in the brain, ventricular enlargement and spinal cord atrophy. Primary progressive patients more often had diffuse abnormalities in the brain and/or spinal cord than did relapsing-remitting and secondary progressive patients. In the entire study population, EDSS correlated with both brain and spinal cord MRI parameters, which were independent. The urological complaint score correlated only with spinal cord MRI parameters. In relapsing-remitting and secondary progressive multiple sclerosis, the correlation between MRI and clinical parameters was better than in the entire population. In this subgroup EDSS variance could be explained best by T1 brain lesion load, ventricle volume and spinal cord cross-sectional area. In the primary progressive subgroup the clinicoradiological correlation was weak for brain parameters but was present between spinal cord symptoms and spinal cord MRI parameters. In conclusion, the different brain and spinal cord MRI parameters currently available revealed considerable heterogeneity between clinical subtypes of multiple sclerosis. In relapsing-remitting and secondary progressive multiple sclerosis both brain and spinal cord MRI may provide a tool for monitoring patients, while in primary progressive multiple sclerosis the clinicoradiological correlation is weak for brain imaging.

Sexual dysfunction in men with multiple sclerosis--a comprehensive pilot-study into etiology.

UNLABELLED: Ideally, the etiological diagnosis of sexual dysfunction in patients with multiple sclerosis is established on the basis of both objective and subjective tests. Accordingly, we assessed sexual function in 16 male patients with multiple sclerosis and complaints of sexual dysfunction by means of subjective data from interviews and questionnaires and objective data, obtained from (psycho)physiological tests. Psychophysiological investigation consisted of measurement of sleep erections and of erectile response to visual erotic stimulation and penile vibration. Urodynamic investigation was used to assess the neurological status of the genital tract. Sixteen male patients with clinically definite multiple sclerosis, complaints of sexual dysfunction and a steady heterosexual relationship participated in the study. The majority of patients had no abnormalities in the objective tests. Only one (1 out of 15) patient showed disturbed sleep-erections, and four (4 out of 12) other patients showed signs of neurological dysfunction of the genital tract. CONCLUSION: In our patient-group, disturbed sleep erections and abnormal findings on urodynamic investigation appeared unrelated to the complaint of erectile dysfunction. Sexual function was related to psychological factors, decreased general sensitivity, and motor impairment.

Urodynamic and clinical effects of noninvasive and minimally invasive treatments in elderly men with lower urinary tract symptoms stratified according to the grade of obstruction.

OBJECTIVES: We investigated the symptomatic and urodynamic effects of several noninvasive and minimally invasive treatment modalities to quantify these effects and to compare subjective and objective results within groups with various degrees of obstruction. METHODS: In a prospective study at one center, 487 patients who completed a full screening program including urodynamic investigation started treatment with watchful waiting, terazosin, transurethral microwave thermotherapy, or laser treatment of the prostate; they were re-evaluated symptomatically and urodynamically after 6 months of therapy. The symptomatic and urodynamic results of 87 patients from another center who underwent transurethral resection of the prostate and who had their second urodynamic evaluation 6 months after surgery were also included. RESULTS: In patients without bladder outlet obstruction (BOO), improvement in maximum flow and symptom scores with little change in the degree of obstruction was most apparent, whereas a decrease of detrusor pressure at maximum flow was observed mainly in patients with BOO. The urodynamic effect but not the symptomatic effect of treatments depended on the initial grade of BOO. Urodynamic changes were more marked in the minimally invasive treatment groups compared with the noninvasive treatment groups. CONCLUSIONS: In symptomatic patients with benign prostatic hyperplasia, symptomatic improvement in the short term does not seem to depend on changes in urodynamic parameters. Future well-controlled studies focusing on the durability of symptomatic and urodynamic effects will be needed to illustrate the relative potential of urodynamic and other clinical parameters to predict a favorable response to current and innovative treatments.

Urodynamic and clinical effects of terazosin therapy in symptomatic patients with and without bladder outlet obstruction: a stratified analysis.

OBJECTIVES: To evaluate clinical and urodynamic changes in patients with and without bladder outlet obstruction (BOO) and to compare the clinical and urodynamic results of terazosin treatment between patients with and without BOO. METHODS: In a prospective study, 97 patients who completed a full screening program including urodynamic investigation with pressure-flow study analysis started treatment with terazosin. A total of 60 patients completed 6 months of treatment and were re-evaluated with International Prostate Symptom Scores (IPSS), uroflowmetry, and urodynamic investigation with pressure-flow study analysis. Patients were stratified using the linear passive urethral resistance relation (lin-PURR) classification according to Schäfer. Patients with a lin-PURR of 3 or more were classified as patients with BOO and patients with a lin-PURR of 2 or less were classified as patients without BOO. The clinical and urodynamic changes within and between the groups with and without BOO were evaluated. RESULTS: Terazosin resulted in significant symptomatic relief (9 points on the IPSS scale; P < 0.01) and a significant improvement of free urinary flow (3.0 mL/s; P < 0.01). In patients with BOO, a statistically significant improvement of all urodynamic obstruction variables (P < 0.01) was shown. In patients without BOO, a significant improvement of free urinary flow (4.4 mL/s; P < 0.01), a statistically significantly improved bladder capacity (increase of 70 mL; P = 0.01), and no statistically significant changes in urodynamic obstruction variables (P > 0.05) were shown. Patients with a hypoactive detrusor were more prone to early dropout. When comparing the changes of symptoms (P = 0.89), quality of life (P = 0.85), and the number of patients with improvements of free uroflow of at least 30% (P = 0.15), there appeared to be no significant difference between the groups with and without BOO. CONCLUSIONS: Although there is a statistically significant difference in urodynamic response to terazosin treatment between patients with and without BOO, we cannot recommend the use of pressure-flow studies in the selection of patients for terazosin treatment because the clinical results of treatment appear not to be significantly different between patients with and without BOO. It seems more useful, and certainly less expensive and less invasive, to start alpha 1-blocker therapy if, on clinical grounds, the urologist considers the patient to be a candidate for alpha 1-blocker therapy, and to continue therapy in those who respond.

The correlation between bladder outlet obstruction and lower urinary tract symptoms as measured by the international prostate symptom score.

PURPOSE: We studied the relationship between lower urinary tract symptoms as measured by the international prostate symptom score (I-PSS) and urodynamic findings in elderly men. MATERIALS AND METHODS: We evaluated 803 consecutive patients with lower urinary tract symptoms via the I-PSS and urodynamics with pressure-flow studies. RESULTS: A statistically significant correlation was found between all I-PSS questions (except intermittency) and objective parameters of obstruction. However, the clinical significance of this finding is minimal because a large overlap of symptom scores exists among patients with different grades of bladder outlet obstruction. The filling component of the I-PSS correlated somewhat better with obstruction than did the voiding component. CONCLUSIONS: It seems impossible to diagnosis bladder outlet obstruction from symptoms alone. It does not even seem possible to define subgroups in which further urodynamic examination is indicated.

Variability of clinical and pressure-flow study variables after 6 months of watchful waiting in patients with lower urinary tract symptoms and benign prostatic enlargement.

PURPOSE: We quantified the physiological variability of clinical and pressure-flow study variables in patients with symptomatic benign prostatic enlargement. MATERIALS AND METHODS: Symptom scores were measured, and advanced urodynamic studies with pressure-flow analysis were performed in 178 patients before and 6 months after a period a watchful waiting. RESULTS: Patients without bladder outlet obstruction experienced significant symptomatic improvement. Symptoms in patients with obvious bladder outlet obstruction did not improve significantly. The reproducibility of mean pressure-flow variables was evident. However, there was an important intra-individual variability. Patients with obvious bladder outlet obstruction showed a significant decreases in detrusor pressure at maximal flow of 14cm. water, a significant decrease in the urethral resistance factor of 7 cm. water and a significant decrease of 1 obstruction class on the linear passive urethral resistance relation nomogram, indicating less severe bladder outlet obstruction. CONCLUSIONS: Mean differences among therapy groups must be regarded critically, especially when the difference are slight and possibly within physiological variability.