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Background: Persistent fetal carotid-vertebrobasilar anastomoses are rare, with an incidence of <1%. The most common anomaly seen in this group is a persistent primitive trigeminal artery; others such as a persistent hypoglossal artery account for less than 15% of all persistent fetal anastomoses, making this finding exceedingly rare. Methods: We present the case of a 32-year-old-female with Poland syndrome (right-sided), who presented with thunderclap headache and reduced level of consciousness secondary to diffuse subarachnoid hemorrhage and hydrocephalus. CT and catheter angiography demonstrated an aneurysm of the V4 segment of the right vertebral artery arising from a persistent right hypoglossal artery, with an absent ipsilateral vertebral artery proximal to the anomaly. Results: Hydrocephalus was treated with an EVD, followed by a successful embolization of the V4 aneurysm with Axium coils. Subsequent MR studies demonstrated minimal recanalization of the aneurysm, and small foci of possible infarcts in the hippocampi. Four months later, the patient has some persistent short term memory difficulties but is otherwise neurologically intact. Conclusions: We present a rare finding of a persistent fetal hypoglossal artery with an associated vertebral aneurysm. The aneurysm was successfully treated endovascularly through coil embolization with minimal residual -neurological deficit. This vascular anomaly was ipsilateral to her Poland Syndrome defects.
Internet cognitive–behavioural therapy (iCBT) for panic disorder of up to 10 lessons is well established. The utility of briefer programmes is unknown.
To determine the efficacy and effectiveness of a five-lesson iCBT programme for panic disorder.
Study 1 (efficacy): Randomised controlled trial comparing active iCBT (n=27) and waiting list control participants (n=36) on measures of panic severity and comorbid symptoms. Study 2 (effectiveness): 330 primary care patients completed the iCBT programme under the supervision of primary care practitioners.
iCBT was significantly more effective than waiting list control in reducing panic (g=0.97, 95% CI 0.34 to 1.61), distress (g=0.92, 95% CI 0.28 to 1.55), disability (g=0.81, 95% CI 0.19 to 1.44) and depression (g=0.79, 95% CI 0.17 to 1.41), and gains were maintained at 3 months post-treatment (iCBT group). iCBT remained effective in primary care, but lower completion rates were found (56.1% in study 2 v. 63% in study 1). Adherence appeared to be related to therapist contact.
The five-lesson Panic Program has utility for treating panic disorder, which translates to primary care. Adherence may be enhanced with therapist contact.
Contact stress transducers were placed in subglacial bedrock and used to monitor continuously shear stress and normal pressure changes at the contact with the overriding glacier sole 100 m beneath the surface of the Glacier d’Argentière during periods in summer 1973 and spring 1975. The measured fluctuations in normal pressure and shear stress do not appear to be related to changes in sliding velocity. Analysis of the data reveals short-term fluctuations in normal pressure and shear stress which appear to be related to the passage of individual large debris particles or groups of particles over the transducer. The shear stress appears to be a function of the volume concentration of debris in the ice. The volume concentration at any point appears to be partially dependent on a “streaming” process by which basal debris-rich ice tends to flow around the lateral flanks of hummocks on the glacier bed. Where sub-glacial cavities occur, this streaming effect appears to be dependent on the extent of cavitation and thus on ice overburden pressure and velocity. It is suggested that this process can account for an apparent lag between changes in normal pressure and shear stress.
The maximum ratio between shear and normal stress averaged over a period of 10 min was 0.44. This is equivalent to a spatial average over 0.3 cm. Debris concentrations in basal ice of up to 43% by volume occurred. It is suggested that concentrations of this order are common at the base of temperate glaciers and thus that a significant part of the drag at the base of a glacier may be contributed by frictional interactions between the basal-debris load and the bed.
A numerical model is used to simulate ice-sheet behaviour in Europe through the last glacial cycle. It is used in two modes: a forward mode, in which the model is driven by a proxy palaeoclimate record and the output compared with a geological reconstruction of ice-sheet fluctuation; and an inverse mode, in which we determine the climate function that would be required to simulate geologically reconstructed ice-sheet fluctuations.
From these simulations it is concluded that extra-glacial climates may be poor predictors of ice-sheet surface climates, and that climatic transitions during the glacial period may have been much more rapid and the intensity of warming during the early Holocene much greater than hitherto supposed. Stronger climate forcing is required to drive ice-sheet expansion when sliding occurs at the bed compared with a non-sliding bed. Sliding ice sheets grow more slowly and decay more rapidly than non-sliding ice sheets with the same climate forcing.
Transitional cell carcinoma (TCC) of the renal pelvis is a rare urological malignancy, with only a handful of cases of metastases to the brain reported in literature. We aim to present a case of intracranial metastasis in a female patient with history of renal pelvic carcinoma, and review existing literature of brain metastases from renal pelvic TCC. Methods: We searched PubMed, EMBASE, and MEDLINE from 1966 to January 2016 for published case reports written in English. Results: Five published case reports describe intracranial metastases from renal pelvic TCC. Our case is a 56-year-old woman with known high grade renal pelvic carcinoma and pulmonary metastases, who presented nine years after her initial diagnosis with mild left side weakness and headaches. She was found to have two lesions in the right cerebral hemisphere and underwent surgical resection of the larger right frontal lobe mass. Her neurologic symptoms improved postoperatively. She declined whole brain radiotherapy and remains stable at 6 months’ follow-up. This is the first published case of presentation of brain metastases from pelvic TCC more than 12 months after diagnosis of the primary cancer. Conclusion: There is minimal literature of renal pelvic TCC metastasizing to the brain. However, as systemic chemotherapy leads to improved survival from the primary cancer, it is possible for more cases to appear, necessitating increased awareness from the healthcare team.
Background: Closed cell carotid stent fracture is rare. From our literature review, we present the first reported case in English literature of a carotid stent fracture post angioplasty for an in-stent stenosis. Methods: Case Report Results: 72-year-old male underwent left carotid stenting for symptomatic ulcerated stenosis of the proximal aspect of left ICA (71% stenosis with post-stenting 55% residual stenosis). His right ICA and right vertebral artery were occluded. 2 months later, he presented with TIA’s and severe in-stent stenosis in the proximal left ICA measuring 1 mm in diameter. Satisfactory balloon (5×40 mm) angioplasty was done with residual stenosis measuring 2.5 mm in diameter. 8 months later he presented with symptoms of compromised cerebral perfusion. Workup showed a stent fracture distally at the site of severe ICA stenosis secondary to atherosclerotic calcified plaque causing blood flow changes. His PSV (peak systolic velocity) in the left ICA was 383 m/s. As such he underwent left ICA re-stenting for symptomatic severe left ICA stenosis of 70% with 40% residual stenosis following stent deployment. Conclusions: Carotid stent fracture post balloon angioplasty for recurrent stenosis is rare but of paramount importance. We demonstrate re-stenting as a viable treatment modality when patient profile is not amenable to a surgical revascularization procedure.
Background: Abciximab is used for the treatment of thromboembolism occuring during endovascular procedures, however the experience with intra-arterial infusion is limited. The objective is to evaluate its safety and effectiveness during coiling complications. Methods: From an aneurysm coiling database, patients treated with intra-arterial abciximab due to thrombotic complications were selected. Patient were classified either as non-ruptured aneurysm for elective coiling or presenting with subarachnoid hemorrhage. They all had preand post-procedure cerebral angiography performed at our institution as part of routine work-up. Success rate was based on recanalization seen on cerebral angiography. Complications of using abciximab were reported. Results: 35 of 441 coiling patients had a thrombotic complication. 13 of them were treated using intra-arterial infusion of abciximab. 2 patients were male, median age 59. 6 patients presented with sub-arachnoid haemorrhage. 84 % of patients had at least partial recanalization, while 38 % experienced complete recanalization of the parent vessel. 45 % of patients had complications, none severe. 2 patients had aneurysm recanalization, 3 distal migration of thrombus and 1 had haemorrhage (non ruptured aneurysm). Conclusions: Inspite of being considered a safer alternative, use of intrarterial abciximab has potential risks, including hemorrhage, distal thromboembolism and aneurysm recanalization.
All explosive volcanic eruptions generate volcanic ash, fragments of rock that are produced when magma or vent material is explosively disintegrated. Volcanic ash is then convected upwards within the eruption column and carried downwind, falling out of suspension and potentially affecting communities across hundreds, or even thousands, of square kilometres. Ash is the most frequent, and often widespread, volcanic hazard and is produced by all explosive volcanic eruptions. Although ash falls rarely endanger human life directly, threats to public health and disruption to critical infrastructure services, aviation and primary production can lead to potentially substantial societal impacts and costs, even at thicknesses of only a few millimetres. Communities exposed to any magnitude of ash fall commonly report anxiety about the health impacts of inhaling or ingesting ash (as well as impacts to animals and property damage), which may lead to temporary socio-economic disruption (e.g. evacuation, school and business closures, cancellations). The impacts of any ash fall can therefore be experienced across large areas and can also be long-lived, both because eruptions can last weeks, months or even years and because ash may be remobilised and re-deposited by wind, traffic or human activities.
Given the potentially large geographic dispersal of volcanic ash, and the substantial impacts that even thin (a few mm in thickness) deposits can have for society, this chapter elaborates upon the ash component of the overviews provided in Chapters 1 and 2. We focus on the hazard and associated impacts of ash falls; however, the areas affected by volcanic ash are potentially much larger than those affected by ash falling to the ground, as fine particles can remain aloft for extended periods of time. For example, large portions of European airspace were closed for upto five weeks during the eruption of Eyjafjallajökull, Iceland, in 2010 because of airborne ash (with negligible associated ash falls outside of Iceland). The distance and area over which volcanic ash is dispersed is strongly controlled by wind conditions with distance and altitude from the vent, but also by the size, shape and density of the ash particles, and the style and magnitude of the eruption. These factors mean that ash falls are typically deposited in the direction of prevailing winds during the eruption and thin with distance. Forecasting ash dispersion and the deposition ‘footprint' is typically achieved through numerical simulation.
Background: Endometrial carcinoma (EC) is a rare cause of central nervous system metastases, with only 115 cases reported in the literature. There have only been 4 cases reported in the literature for the serous carcinoma subtype. This case study describes a new case of serous carcinoma metastasizing to the brain and demonstrates some of the potential characteristics of this subset. Case: A 77 year old female presented to the emergency department with a 2 week history of progressive left sided weakness and speech difficulties, and a known history of EC diagnosed approximately 3 years earlier. Imaging showed a right temporoparietal tumour. She underwent debulking of this tumour and was found to have a metastasis from her previously known serous carcinoma. Results: In comparing the serous subtype to the 115 known cases, many characteristics show similar patterns to EC as a whole; there could be a predominance to infratentorial lesions with the serous subtype, as 2/4 known metastases were cerebellar compared to only 25% of all endometrial carcinomas. Conclusions: There are possibly different characteristics of metastasizing of various EC subtypes. Before any conclusions can be drawn about the characteristics of any subtype, more data needs to be available for accurate interpretation.
The aims of the present study were to determine compliance with current advice on vitamin D and to assess the influence of season, dietary intake, supplement use and deprivation on vitamin D status in pregnant mothers and newborns in the north of Scotland where sunlight exposure is low. Pregnant women (n 1205) and their singleton newborns were studied in the Aberdeen Maternity Hospital (latitude 57°N) between 2000 and 2006. Plasma 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3 were measured at 19 weeks of gestation in mothers and at delivery in newborns. During pregnancy, 21·0 (95 % CI 18·5, 23·5) % of women took vitamin D supplements. The median intake was 5 μg/d and only 0·6 (95 % CI 0·1, 1·0) % took the recommended 10 μg/d. Supplement use, adjusted for season, dietary intake and deprivation, significantly increased maternal 25-hydroxyvitamin D (25(OH)D) by 10·5 (95 % CI 5·7, 15·2) nmol/l (P< 0·001); however, there was no significant effect on cord 25(OH)D (1·4 (95 % CI − 1·8, 4·5) nmol/l). The biggest influence on both maternal and cord 25(OH)D was season of birth (P< 0·001). Compared with the least deprived women (top three deciles), the most deprived pregnancies (bottom three deciles) were characterised by a significantly lower seasonally adjusted 25(OH)D ( − 11·6 (95 % CI − 7·5, − 15·7) nmol/l in the mother and − 5·8 (95 % CI − 2·3, − 9·4) nmol/l in the cord), and a lower level of supplement use (10 (95 % CI 4, 17) v. 23 (95 % CI 20, 26) %). More should be done to promote vitamin D supplement use in pregnancy but the critical importance of endogenous vitamin D synthesis, and known adaptations of fat metabolism specific to pregnancy, suggest that safe sun advice may be a useful additional strategy, even at high latitude.
The hydrolysis and gelation sequence occurring in the formation of a filament or a rigid coherent gel from an organic silicate requires a mutual solvent for the organicsilicate and water if it is to proceed successfully. The solvent is usually a water-miscible alcohol. This alcohol can also be a reaction product, which makes the sequence very solvent dependent. The best control of both hydrolysis and gelation is obtained when the alcohol solvent and the organic silicate each contain the same alkoxy group. The gel resulting is also the best binder for refractory grain. Suitable systems are ethyl silicate and ethanol also isopropyl silicate and isopropanol. The formation of rigid coherent gels, or filaments which on firing convert to ceramic fibres, from hydrolysates of ethyl silicate and aluminium chlorhydrate species is also very solvent dependent. With glycol solvents, aluminium chlorhydrates do not form filaments nor ceramic fibres. With ethanol as solvent, aluminium chlorhydrate-polyol complexes readily form rigid coherent gels and filaments, hence ceramic fibres, because the polyol complex is formed by displacing coordinated water in the aluminium chlorhydrate. This reduces the amount of water available for reaction, which optimises filament and fibre formation.
Sol-gel routes were developed to prepare densified PZT fibers. The effects of the degree of hydrolysis and the addition of an organic polymer to the precursor sol on fiber forming ability were investigated. Results on the crystalline and microstructural development of gels and fibers are presented. The effects of the incorporation of excess PbO and sintering atmosphere are also discussed, particularly in relation to densification.
A series of PZT precursor solutions was prepared which incorporated excess PbO to give the composition Pb1+xZr0.53Ti0.47O3+x, where 0 < × < 0.3. These solutions were spin coated on platinized Si wafers and fired at elevated temperatures up to 750C for 30 mins. After crystallization into single-phase perovskite, the films were studied using XRD, optical microscopy and electrical characterization techniques (hysteresis loops and dielectric properties). It was found that the presence of excess PbO significantly improved the PZT films in terms of phase assemblage, microstructure and electrical properties. Under optimized conditions, films with dielectric constants of around 3000 can be obtained.
Organic-inorganic hybrids, with tailorable properties via control of their chemistries, offer great potential for many optical, electrical and mechanical applications. PDMS-based materials have been fabricated, having low optical losses of < 0.15 dB/cm but the dielectric properties of these hybrids have rarely been explored or reported. In the present study, the dielectric properties of PDMS:SiO2:TiO2 films are explored as a function of composition and curing temperature using an impedance analyzer. Dielectric spectroscopy was also performed to investigate the dielectric relaxation and dispersion behaviors. Results indicate that εr at 1 MHz ranges from 3 to 5. Residual hydroxyl and alkoxy species in the films contribute to the overall polarizabilities especially at low frequencies ( < 100 kHz).
Positioning in the urban environment using GNSS is hampered by poor satellite availability due to signal obstruction created by both man-made and natural features of the urban environment. In addition, range measurement to satellites for positioning and for navigation is severely degraded by the multipath effect. The arrival and continuous enhancement of computerised geometric city models makes it possible to tackle these problems through modelling. In this paper description is given of a method for determining the local multipath environment, defined by the surfaces within a city model that will cause disruptive signal reflections to be presented to a receiver. An example simulation is performed, and graphical and numerical results are produced.
Although approximately 95% of disease caused by nontyphoidal salmonella is transmitted by foodborne vehicles, four documented salmonella outbreaks in the 1990s have been traced to contact with young poultry. No environmental studies of source hatcheries were completed. This case-control study was performed by comparing culture-confirmed Salmonella Infantis in Michigan residents, identified between May and July 1999, with two age- and neighbourhood-matched controls. Eighty environmental and bird tissue samples were collected from an implicated hatchery; all salmonella isolates underwent pulsed-field gel electrophoresis (PFGE) analysis. The study included 19 case-patients sharing the same PFGE subtype and 37 matched controls. Within 5 days before illness onset, 74% of case-patients resided in households raising young poultry compared with 16% of controls (matched OR 19.5; 95% CI 2.9, 378.1). Eight hatchery samples yielded Salmonella Infantis with PFGE subtypes matching the patients' isolates. This investigation identified birds from a single hatchery as the source of human illness and confirmed the link by matching PFGE patterns from humans, birds and the hatchery environment. Subsequent public health interventions reduced, but did not eliminate, transmission of poultry-associated salmonellosis. Five additional PFGE-linked cases were identified in Spring 2000, necessitating quarantine of the hatchery for depopulation, cleaning and disinfection.
The streptozotocin (STZ)-diabetic rat, the most commonly employed model of experimental diabetic
neuropathy, is characterised by a reduction in nerve conduction velocity, pain threshold and blood flow.
Whether or not structural abnormalities underlie these functional abnormalities is unclear. 10 adult male
Sprague–Dawley STZ-diabetic rats (diabetes duration 27 d) and 10 age-matched (23 wk) control animals
were studied. Motor nerve conduction velocity (m s−1) was significantly reduced in diabetic
(41.31±0.8) compared with control (46.15±1.5) animals (P<0.001). The concentration of sciatic nerve glucose
(P<0.001), fructose (P<0.001) and sorbitol (P<0.001) was elevated, and myoinositol (P<0.001) was reduced
in diabetic compared with control animals. Detailed morphometric studies demonstrated no significant
difference in fascicular area, myelinated fibre density, fibre and axon areas as well as unmyelinated fibre
density and diameter. Endoneurial capillary density, basement membrane area and endothelial cell profile
number did not differ between diabetic and control animals. However, luminal area (P<0.03) was increased
and endothelial cell area (P<0.08) was decreased in the diabetic rats. We conclude there is no detectable
structural basis for the reduction in nerve conduction velocity, pain threshold or blood flow, observed in the
streptozotocin diabetic rat.
The retinal vasculature of postmortem normal human and diabetic
eyes was studied using an
immunohistochemical technique in conjunction with confocal laser scanning
microscopy. The technique,
which stained for von Willebrand factor, allowed both large areas of the
retinal vasculature to be visualised
and abnormalities to be studied in detail without disturbing the tissue
architecture. Only one
microaneurysm, defined as any focal capillary dilation, was observed in
10 normal eyes but numerous
microaneurysms were seen in 4 out of 5 diabetic retinas; counts varied
between 0 and 26 per 0.41 mm2
sample area. Microaneurysms were classified into 3 categories according
to morphology: saccular, fusiform
and focal bulges. Most were saccular, these having no preferred orientation.
The majority of
microaneurysms were associated with just 2 vessels suggesting they were
unlikely to develop at vascular
junctions. The majority were observed to originate from the inner nuclear
layer and were therefore in the
deeper part of the inner retinal capillary plexus. Variation in the staining
of microaneurysms may correlate
with endothelial dysfunction seen clinically as dye leakage during fluorescein
An acutely stressful stimulus such as relocation from a familiar strawed pen to an unfamiliar farrowing crate during birth has been shown to interrupt the birth process and inhibit oxytocin secretion (Lawrence et al, 1992). Both of these departures from normal parturition could be prevented by administration of the Î¼ opioid antagonist naloxone. A likely site of action for this effect is presynaptic Î¼ receptors on noradrenergic nerve terminals in the hypothalamus (Onaka et al, 1995). Such a neuro-endocrine control system, if active in the day prior to birth, might influence the timing of the onset of parturition and its subsequent efficiency even in the absence of a stressful stimulus. This experiment tested this hypothesis.