Repeat operations in patients with anal fistula, a retrospective study across England and Wales.

AIM: This article reports the frequency of repeat operations including waiting times within the National Health Service (NHS) of England and Wales. METHODS: Retrospective study on repeat operations for anal fistula (AF) performed between 1st January 2010 and 31st December 2016. Data were extracted from the national registry of data entered into Hospital Episode Statistics (HES). Patient factors (age, sex, self-declared ethnicity) and geographical location were tested for association with repeat operations and time to the second operation. RESULTS: We analysed 36,223 patients that had an operation for AF within 148 NHS trusts. The median follow-up time was 28 months. The majority of patients (67.4%) had only one operation. Eighty-five per cent of them remained under the care of a single consultant. Six per cent of the repeat surgeries occurred in at least three different treatment sites. Young age and female sex were associated with higher rates of repeat operations. Non-declared and Black or Black British ethnicity were associated with fewer operations. The median waiting time between the first and second operations was 27.4 weeks (IQR: 14.7-55.3); between the second and third 28.0 weeks (IQR: 14.7-57.0); between the third and fourth 29.0 weeks. CONCLUSION: This large real world population-based study shows that the majority of patients with AF undergo only one operation. Patients requiring multiple procedures tend to stay under the care of a small number of consultants but waiting times between operations are long. There is a geographical variation in the number of operations and the time between them.

Vitamin D supplementation and adverse skeletal and non-skeletal outcomes in individuals at increased cardiovascular risk: Results from the International Polycap Study (TIPS)-3 randomized controlled trial.

BACKGROUND AND AIMS: Vitamin D has mostly been tested in Western populations. We examined the effect of high dose vitamin D in a population drawn predominantly from outside of Western countries. METHODS AND RESULTS: This randomized trial tested vitamin D 60,000 IU monthly in 5670 participants without vascular disease but at increased CV risk. The primary outcome was fracture. The secondary outcome was the composite of CV death, myocardial infarction stroke, cancer, fracture or fall. Death was a pre-specified outcome. Mean age was 63.9 years, and 3005 (53.0%) were female. 3034 (53.5%) participants resided in South Asia, 1904 (33.6%) in South East Asia, 480 (8.5%) in South America, and 252 (4.4%) in other regions. Mean follow-up was 4.6 years. A fracture occurred in 20 participants (0.2 per 100 person years) assigned to vitamin D, and 19 (0.1 per 100 person years) assigned to placebo (HR 1.06, 95% CI 0.57-1.99, p-value = 0.86). The secondary outcome occurred in 222 participants (1.8 per 100 person years) assigned to vitamin D, and 198 (1.6 per 100 person years) assigned to placebo (HR 1.13, 95% CI 0.93-1.37, p = 0.22). 172 (1.3 per 100 person years) participants assigned to vitamin D died, compared with 135 (1.0 per 100 person years) assigned to placebo (HR 1.29, 95% CI 1.03-1.61, p = 0.03). CONCLUSION: In a population predominantly from South Asia, South East Asia and South America, high-dose vitamin D did not reduce adverse skeletal or non-skeletal outcomes. Higher mortality was observed in the vitamin D group. REGISTRATION NUMBER: NCT01646437.

Role of indigenous arsenate and iron(III) respiring microorganisms in controlling the mobilization of arsenic in a contaminated soil sample.

In this study two different treatment options were investigated for the release of arsenic from a contaminated soil sample. The first option was based on the "bioaugmentation" principle and involved addition of a pure Fe(III)-reducing culture, i.e. Desulfuromonas palmitatis. The second option consisted in the "biostimulation" of indigenous bacteria and involved simple addition of nutrients. Due to the strong association of As with soil ferric oxides, the reductive dissolution of soil oxides by D. palmitatis lead to 45 % arsenic release in solution (2.15 mM). When only nutrients were supplied to the soil, the same amounts of Fe and As were dissolved with slower rates and most aqueous As was found to be in the trivalent state, indicating the presence of arsenate reducing species. The arsenate reducing microorganisms were enriched with successive cultures, using Na2HAsO4 as electron acceptor. The phylogenetic analysis revealed that the enriched microbial consortium contained Desulfosporosinus species, which are known arsenate reducers.

A XAFS study of plain and composite iron(III) and chromium(III) hydroxides.

Reduction of hexavalent Cr(VI) to the trivalent state is the common strategy for remediation of Cr(VI) contaminated waters and soils. In the presence of Fe the resulting compounds are usually mixed Fe(III)-Cr(III) phases, while, under iron-free conditions, reduction leads to formation of plain Cr(III) hydroxides. Environmental stability of these compounds depends on their structure and is important to understand how different precipitation conditions affect the local atomic order of resulting compounds and thus their long term stability. In current study, typical Cr(VI) environmental remediation products, i.e. plain and mixed Fe(III)-Cr(III) hydroxides, were synthesized by hydrolysis and redox reactions and their structure was studied by X ray diffraction and X ray absorption fine structure techniques. Plain Cr(III) hydroxide was found to correspond to the molecular formula Cr(OH)3·3H2O and was identified as crystalline in XRD. However, the same compound when examined by EXAFS did not exhibit any clear local order in the range of EXAFS detectable distances, i.e. between 0 and 5Å. Namely, EXAFS spectroscopy detected only contribution from the first nearest neighboring (Cr-O) shell, suggesting that CrO6 octahedra interconnection is loose, in accordance with the suggested anti-bayerite structure of this compound. Mixed Fe(III)-Cr(III) systems resembled 2-line ferrihydrite irrespective of the synthesis route. Analysis of Fe-K-EXAFS and Cr-K-EXAFS spectra indicated that FeO6 octahedra are bonded by sharing both edges and corners, while CrO6 octahedra seem to prefer edge sharing linkage. EXAFS data also suggest that Fe-Cr hydroxide produced by hydrolysis presents a better arrangement of CrO6 octahedra compared to the redox product.

Synthesis, characterization and stability of Cr(III) and Fe(III) hydroxides.

Chromium is a common contaminant of soils and aquifers and constitutes a major environmental problem. In nature, chromium usually exists in the form of two oxidation states, trivalent, Cr(III), which is relatively innocuous for biota and for the aquatic environment, and hexavalent, Cr(VI) which is toxic, carcinogenic and very soluble. Accordingly, the majority of wastewater and groundwater treatment technologies, include a stage where Cr(VI) is reduced to Cr(III), in order to remove chromium from the aqueous phase and bind the element in the form of environmentally stable solid compounds. In the absence of iron the final product is typically of the form Cr(OH)3·xH2O whereas in the presence of iron the precipitate is a mixed Fe(1-x)Crx(OH)3 phase. In this study, we report on the synthesis, characterisation and stability of mixed (Fex,Cr1-x)(OH)3 hydroxides as compared to the stability of Cr(OH)3. We established that the plain Cr(III) hydroxide, abiding to the approximate molecular formula Cr(OH)3·3H2O, was crystalline, highly soluble, i.e. unstable, with a tendency to transform into the stable amorphous hydroxide Cr(OH)3(am) phase. Mixed Fe0.75Cr0.25(OH)3 hydroxides were found to be of the ferrihydrite structure, Fe(OH)3, and we correlated their solubility to that of a solid solution formed by plain ferrihydrite and the amorphous Cr(III) hydroxide. Both our experimental results and thermodynamic calculations indicated that mixed Fe(III)-Cr(III) hydroxides are more effective enhancers of groundwater quality, in comparison to the plain amorphous or crystalline Cr(III) hydroxides, the latter found to have a solubility typically higher than 50µg/l (maximum EU permitted Cr level in drinking water), while the amorphous Cr(OH)3(am) phase was within the drinking water threshold in the range 5.7

Splenic infarction due to septic emboli from bacterial endocarditis: A previously unreported cause of hyperamylasaemia.

We present what maybe the only case of splenic infarction causing hyperamylasaemia in a patient with bacterial endocarditis. A 49-year-old gentleman presented a 24 hour history of vomiting, abdominal pain and fever. Clinical examination showed diffuse upper abdominal tenderness, a mild tachycardia and a low grade pyrexia. Blood investigations showed a hyperamylasaemia. His failure to improve on treatment for a provisional diagnosis of alcohol induced pancreatitis lead to a CT abdomen, which showed a splenic infarct and an echo showing aortic valve vegetation's as a source of emboli. He underwent urgent aortic valve replacement with a tissue valve following which he made an uncomplicated recovery.

Structure and coherence of reasoning ability in Down Syndrome adults and typically developing children.

The present study investigates the ability of Down Syndrome (DS) adults to reason: (a) deductively with transitivity (linear and reverse relations) and categorical syllogisms (all-some relations); (b) inductively with classical verbal analogies and non-verbal analogical reasoning (Raven's Coloured Progressive Matrices); and (c) to retain information in short-term memory. The results have shown that: (i) The Down Syndrome adults did not differ from typically developing children, matched on expressive and verbal ability, in transitivity and non-verbal analogical thinking; (ii) they differed in categorical reasoning, classical verbal analogies and short-term memory. Application of a structural model demonstrated that, despite differences in slope means in the three measures, the structure of functioning within-and-across all domains of cognition tests and its growth pattern, equally reliable and coherent, goes in parallel for the Down Syndrome adults and the typically developing children. The results are discussed within the context of the two-group developmental and difference approach.

Perception, representation and recognition: a holistic view of recognition.

It is clear that humans have mental representations of their spatial environments and that these representations are useful, if not essential, in a wide variety of cognitive tasks such as identification of landmarks and objects, guiding actions and navigation and in directing spatial awareness and attention. Determining the properties of mental representation has long been a contentious issue (see Pinker, 1984). One method of probing the nature of human representation is by studying the extent to which representation can surpass or go beyond the visual (or sensory) experience from which it derives. From a strictly empiricist standpoint what is not sensed cannot be represented; except as a combination of things that have been experienced. But perceptual experience is always limited by our view of the world and the properties of our visual system. It is therefore not surprising when human representation is found to be highly dependent on the initial viewpoint of the observer and on any shortcomings thereof. However, representation is not a static entity; it evolves with experience. The debate as to whether human representation of objects is view-dependent or view-invariant that has dominated research journals recently may simply be a discussion concerning how much information is available in the retinal image during experimental tests and whether this information is sufficient for the task at hand. Here we review an approach to the study of the development of human spatial representation under realistic problem solving scenarios. This is facilitated by the use of realistic virtual environments, exploratory learning and redundancy in visual detail.

View dependence in scene recognition after active learning.

Human spatial encoding of three-dimensional navigable space was studied, using a virtual environment simulation. This allowed subjects to become familiar with a realistic scene by making simulated rotational and translational movements during training. Subsequent tests determined whether subjects could generalize their recognition ability by identifying novel-perspective views and topographic floor plans of the scene. Results from picture recognition tests showed that familiar direction views were most easily recognized, although significant generalization to novel views was observed. Topographic floor plans were also easily identified. In further experiments, novel-view performance diminished when active training was replaced by passive viewing of static images of the scene. However, the ability to make self-initiated movements, as opposed to watching dynamic movie sequences, had no effect on performance. These results suggest that representation of navigable space is view dependent and highlight the importance of spatial-temporal continuity during learning.

Light source dependence in shape from shading.

We investigated shape constancy in human shape from shading under variations of illuminant direction using a local attitude probe in conjunction with a perturbation analysis. Stimuli were computer generated and depicted ellipsoids in a structured setting. Even with these simple shapes subjects settings were systematically biased in the illuminant direction and were consistent with a regression to image luminance gradients. These biases were reduced for high albedo scenes where interreflections make image illuminance more dependent on scene geometry. Adding texture to the surface reduced but did not eliminate this bias. These results suggest that we can expect little constancy in shape from shading under variations of illuminant direction without constraints from other cues.

Perturbation study of shading in pictures.

Pictorial relief was measured for a series of pictures of a smooth solid object. The scene was geometrically identical for all pictures, but the rendering was different. Whereas all pictures were monochrome full-scale photographs, they were taken under different illuminations of the scene, the source being frontal and displaced towards either the upper left, the upper right, the lower right, or the lower left. It was found that different illuminations led to significantly different, systematic alterations of pictorial relief. It is concluded that though shape constancy under changes in illumination might be said to rule in the first rough approximation, the deviations from true constancy are indeed both significant and systematic. Different from either stimulus-reduction or cue-conflict paradigms, this 'perturbation analysis' shows that shading is used as an important source of information even if the particular illumination appears to be ignored at first blush. For all subjects, brighter parts in the stimulus were consistently interpreted as being nearer in pictorial space, both for the global layout and for the subsidiary relief.

Surface gradients, contours and the perception of surface attitude in images of complex scenes.

Sophisticated computer graphics were used to generate images of three-dimensional blocks-world scenes to investigate the perception of surface attitude. Three types of surface primitive (planar blocks, cylinders, and ellipsoids) were combined to form structured settings. The experiments were designed to investigate whether surface-based information such as gradients in shading and texture provide any significant advantage in attitude judgments over information derived from object contours. Images of shaded, textured, and line-drawn surfaces formed the stimulus set. The subjects' task consisted of setting an attitude probe on different parts of the scene so that the probe appeared to be locally coplanar with the perceived surfaces. Analysis of settings according to attitude components, slant and tilt, shows remarkable agreement in slant settings for the shaded and line-drawn scenes but poor correlation between shaded and textured scenes. Similarly, tilt was also easily judged in shaded and line-drawn scenes and the experiments indicate that explicit surface boundaries are important for stable tilt perception. In general, the results suggest that, for the simple surfaces employed here, surface cues provide little extra information beyond that which is derived from contours.

Shape constancy in pictorial relief.

Pictorial relief was measured for a series of pictures of a smooth solid object. The scene was geometrically identical (ie the perspective of the three-dimensional scene remained the same) for all pictures, the rendering different. Some of the pictures were monochrome full-scale photographs taken under different illumination of the scene. Also included were a silhouette (uniform black on uniform white) and a 'cartoon'-style rendering (visual contour and key linear features rendered in thin black line on a uniform white ground). Two subjects were naive and started with the silhouette, saw the cartoon next, and finally the full-scale photographs. Another subject had seen the object and did the experiment in the opposite sequence. The silhouette rendering is impoverished, but has considerable relief with much of the basic shape. The cartoon rendering yields well-developed pictorial relief, even for the naive subjects. Shading adds only small local details, but different illumination produces significant alterations of relief. It is concluded that shape constancy under changes in illumination is dominant throughout, but that the (small) deviations from true constancy reveal the effect of cues such as shading in a natural setting. Such a ¿perturbation analysis' appears more promising than either stimulus-reduction or cue-conflict paradigms.

Correlation of atherectomy specimen histology with coronary arteriographic lesion morphologic appearance in patients with stable and unstable angina.

Complex lesions on coronary arteriography are seen commonly in patients with unstable angina and have been considered to be evidence of ruptured plaque with or without thrombus. To investigate the cause of complex lesions the histologic findings in atherectomy-derived specimens in 111 patients were correlated with lesion morphologic appearance on coronary arteriography. Among 91 patients with complex lesions, 81.3% had thrombus and 57.1% had evidence of plaque rupture. Of 20 patients with smooth lesions, 15% had thrombus and 10% had plaque rupture on histologic evaluation (p < 0.01). On clinical correlation in 86 (83.3%) patients unstable angina was associated with thrombus, or plaque rupture (63.3%), or both on histologic evaluation (p < 0.001 compared with stable angina). Complex lesions not associated with thrombus or plaque rupture occurred mainly (83.3%) in patients with stable angina. Our findings support the concept that complex lesions are usually due to recent thrombus, plaque rupture, or both in patients with unstable coronary syndromes but may be due to remote plaque disruption in patients with stable angina.

The triggering role of physical injury in the onset of peripheral arthritis in seronegative spondyloarthropathy.

Three more cases of B27-positive patients who developed peripheral arthritis immediately after trauma are reported. The first had an exacerbation of arthritis in the right hip after falling from her motor-bike. The second had arthritis of the distal interphalangeal (DIP) joint of the right forefinger after shutting his finger in the door of his car. The third had arthritis of the right sternoclavicular joint after a road-accident while fastening her safety belt.

Differential diagnosis between osteitis condensans ilii and sacroiliitis.

Sacroiliitis of seronegative spondyloarthropathy may sometimes show on pelvis plain films findings indistinguishable from those of osteitis condensans ilii. Computed tomography (CT) can differentiate earlier than plain radiography between the 2 conditions; furthermore, it should also be possible to make this differentiation clinically. The aim of our study was to verify whether the criteria recently proposed by the European Spondylarthropathy Study Group (EESG) for the classification of spondyloarthropathy are useful. CT scans through the synovial part of the sacroiliac joints of 7 consecutive patients meeting the ESSG criteria and showing typical findings of osteitis condensans ilii on plain films were mixed with those of 15 consecutive patients with osteitis condensans ilii not meeting the ESSG criteria. Scans were examined for joint space and surface abnormalities blindly and independently by 2 observers. Six patients in the spondyloarthropathy group and one in the osteiitis condensans ilii group showed clear erosions and/or joint space narrowing of less than 2 mm in at least one joint. The difference was statistically significant (p less than 0.001). Our results suggest that by using criteria valid for the whole group of seronegative spondyloarthropathies, it is possible to differentiate clinically between seronegative spondyloarthropathies with sacroiliitis mimicking osteitis condensans ilii and "true" osteitis condensans ilii.

Trauma and seronegative spondyloarthropathy: report of two more cases of peripheral arthritis precipitated by physical injury.

Two more cases of B27 associated peripheral arthritis triggered by physical injury are reported. One patient developed arthritis after a minor insult and in the other Reiter's syndrome occurred after the injury. Possibly, trauma causes release of self antigens from the injured joints.