The potential for nitric oxide (NO) metabolites (e.g. inorganic nitrite) to act as stable stores of “Transported Nitric Oxide” has excited huge interest due to the substantial potential therapeutic avenues. The prospect developing of a “silver bullet” that could target areas most in need of vasodilatation, by releasing NO in areas of hypoxia and ischaemia, could prove a massive advance in the treatment of vascular disease. In this thesis I examine the effects of nitrite infusion in both hypoxia and normoxia. I examine the effects both in health and heart failure, and investigate the potential roles of Nitric Oxide Synthase (NOS) and Xanthine Oxidase (XO) in mediating the reduction of nitrite. We found, and were the first to report in man, that intra-arterial infusions of nitrite had little effect upon the vasculature in high oxygen tension environments but led to significant vasodilatation during hypoxaemia. We found that patients suffering with Chronic Heart Failure responded differently to nitrite infusion to healthy controls, possibly as a result of differences in redox-stress. In healthy volunteers, at rest, neither NOS nor XO appeared to play a significant role in nitrite induced vasodilatation in normoxia and mild hypoxia. We found that vascular myoglobin contributes to the reduction of nitrite to nitric oxide and may play a role in prolonging the vasodilatation induced by nitrite infusion.

Enterohaemorrhagic E. coli (EHEC) are important gastrointestinal pathogens of humans. E. coli serotype O157:H7 is the EHEC most commonly associated with human illness. E. coli O157:H7 is carried asymptomatically by cattle which form an important reservoir for the bacterium. E. coli O157:H7 has been found to colonise at the terminal rectum of cattle in preference to other sites in the bovine gastrointestinal tract. The first objective of this work was to characterise the roles of bacterial secreted components responsible for key functions in the modulation of host defences against EHEC. Data presented here reaffirms the role of flagellin in the elicitation of a proinflammatory response in a cultured human epithelial cell line; however, the response of a bovine epithelial cell line to bacterial secreted products was not affected by the presence or absence of flagellin. A role in the modulation of the host response for the StcE protease was also investigated: although its role in interaction with the bovine host was not established, bovine secretory antibodies to StcE were detected in rectal mucosal scrapings from an E. coli O157:H7-challenged calf, suggesting that StcE is expressed and recognised in vivo. The second key objective was to isolate E. coli from the bovine intestinal tract in order to define the colonisation patterns of E. coli within the bovine intestinal tract and relate this to bacterial genotype and to provide bovine E. coli isolates to test for inhibitory activity against E. coli O157:H7 which may yield bacteria with potential as probiotic agents with a view to reducing the prevalence of EHEC in cattle. Genotypic analysis of bovine resident E. coli confirmed that these strains carry a variety of virulence factor-encoding genes; however, certain dominant genotypes were identified and the genomic structure of representative isolates was predicted by genomic microarray. EHEC-related genotypes were found to be positively associated with colonisation at the rectum, whereas non-EHEC genotypes were found to colonise multiple intestinal sites without showing any apparent site-specificity. The third and final objective of this analysis was to carry out genotypic analysis of Scottish EHEC strains in order to predict whether increased incidence of EHEC infection in Scotland may be related to the presence of EHEC strains carrying altered complement of virulence factor-encoding genes. The analysis of EHEC isolated in Scotland revealed that these strains exhibit a genomic profile which is largely typical of EHEC isolated elsewhere, although there were certain differences in the carriage of a certain genomic elements. The results presented here support the proposal that bacteriophages are the key mediators of genetic variability among E. coli isolates.

Depression is one of the most common causes of periods of disability. There is evidence suggesting that the serotonin system is involved in the pathophysiology of depression. It has been suggested that synaptic serotonin levels are reduced in depressed patients, and that pharmacological blockade with antidepressants of the serotonin transporter (SERT) would result in alleviated symptoms of depression by enhancing serotonin neurotransmission. Since depression can be treated with antidepressants that target SERT, and a recently discovered 5-HTT gene-linked polymorphic region (5-HTTLPR) of the SERT gene has been shown to predispose to depression, the SERT assumes a key role in depression. Traditionally, depression severity was assessed using psychological testing of patients. However in the last 20 years, neuroimaging techniques using magnetic resonance imaging (MRI) of brain structures and molecular single photon emission computed tomography (SPECT) evolved which appear promising to better understand the pathophysiology at the tissue level. However, preclinical data on abnormalities that involve the serotonin system are limited. The studies presented in this thesis attempt to shed more light on the feasibility of using the novel MRI technique diffusion tensor imaging (DTI), and SPECT to detect disturbances of the serotonin system. Firstly, in order to elucidate the capabilities of DTI as a research tool in the detection of conceivably mild changes in white matter involving the serotonin system, a mouse model of life-long SERT deficiency was studied. Secondly, in order to validate DTI image processing methodology, a mouse model with reportedly profound myelin dysfunction was examined. Histology techniques were applied to the same mouse brains in order to explore the tissue correlate of the DTI signal changes. Thirdly, as myelin was hypothesised to interact with the serotonin system, in vitro autoradiography of SERT in mice with widespread hypomyelination was conducted in order to test this hypothesis. Lastly, in a rat model of SERT depletion, the relative abilities of a well established SPECT radioligand, [125I]βCIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane), and a relatively novel SERT tracer, [123I]ADAM (2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine) were examined using micro-SPECT. The data demonstrate that DTI did not detect any changes in white matter organisation in SERT-deficient mice. Surprisingly, subtle changes in white matter microstructure were detected in mice that were haploinsufficient for SERT, i.e. heterozygous null mice, displaying a 50 % SERT reduction compared to WT as detected using DTI. On the other hand, profound hypomyelination was detected using DTI in another mouse model with white matter pathology, and correlations between DTI and histopathological markers were present, indicating that this technology provides good indications of severe pathology, while small changes, if present, may be missed. In addition, the SERT availability appeared not to be affected in mice with widespread hypomyelination. While post mortem autoradiography of SERT-depleted rats showed widespread reductions in SERT binding using dedicated specific SERT ligands, micro-SPECT using [125I]βCIT and [123I]ADAM did not show any differences. [125I]βCIT delivered good quality brain SPECT images, however analysis of [123I]ADAM scans was hampered by the poor definition of structures. Thus this thesis provides important information on the feasibility, and sensitivity of current neuroimaging modalities. In addition, methodological flaws and uncertainties in the current literature were identified, which underpins the need for improving and standardising methodological approaches, particularly in SPECT imaging.

The Large Eddy Simulation (LES) technique with the Smagorinsky-Lilly dynamic subgrid model and two-equation Standard k-ω Transitional turbulence model are applied to investigate non-spiral and spiral blood flow through three dimensional models of arterial stenosis and aneurysm. A spiral pattern of blood flow is thought to have many beneficial effects on hemodynamics. Previous computational studies on spiral blood flow involve only steady spiral flow in a straight stenosed pipe without considering an upstream curved section of the artery. But a spiral pattern in the blood flow may exist due to the presence of an upstream curved section in the artery. On the other hand, pressure is generally considered a constant quantity in studies on pulsatile flow through either arterial stenosis or aneurysm; however, blood pressure is a waveform in a physiological flow. Although cosine-type or smooth regular stenoses are generally taken in investigations of blood flow in a three-dimensional model of arterial stenosis, in reality, stenoses are of irregular shape. Besides stenosis and aneurysm, another abnormal condition of the artery is the presence of stenosis with an adjacent aneurysm in the same arterial segment, especially in the posterior circulation. A study on (steady or pulsatile) flow through such arterial stenosis with an adjacent aneurysm in the same arterial segment is not available so far. Therefore, taking above things into consideration, thorough investigations of steady and unsteady pulsatile non-spiral and spiral blood flow in three-dimensional models of stenosis and aneurysm are needed to give a sound understanding of the transition-to-turbulence of blood flow due to stenosis and aneurysm and to study the the effects of spiral velocity on the transition-to-turbulence. The LES technique has mostly been used to investigate turbulent flow in engineering fields other than bio-fluid mechanics. In the last decade, LES has seen its excellent potential for studying the transition-to-turbulence of physiological flow in bio-fluid mechanics. Though the k-ω Transitional model is used in few instances, mainly LES is applied in this study. Firstly, investigations of steady non-spiral and spiral blood flow through threedimensionalmodels of cosine-type regular stenosed tube without and with upstream curved segment of varying angles of curvature are performed by using the k-ω Transitional model and LES. A fully developed Poiseuille velocity profile for blood is introduced at the inlets of the models. To introduce a spiral effect at the inlet, onesixth of the bulk velocity is taken as the tangential velocity at the inlet along with the axial velocity profile there. Secondly, physiological pulsatile non-spiral and spiral blood flow through a three-dimensional model of a straight tube having cosine-type regular stenosis are investigated by using mainly LES. A two-equation k-ω Transitional model is also used in one non-spiral flow case. The first four harmonics of the Fourier series of pressure pulse are used to generate physiological velocity profiles at the inlet. At the outlet, a pressure waveform is introduced. The effects of percentage of area reduction in the stenosis, length of the stenosis, amplitude of pulsation and Womersley number are also examined. Thirdly, transient pulsatile non-spiral and spiral blood flow through a threedimensional model of irregular stenosis are investigated by applying LES and comparison is drawn between non-spiral flow through a regular stenosis and that through an irregular stenosis. Lastly, pulsatile non-spiral and spiral blood flow through a three-dimensional model of irregular stenosis with an adjacent post-stenotic irregular aneurysm in the same arterial segment are studied by applying LES and the k-ω Transitional model. The effects of variation in spiral velocity are also examined. The results presented in this thesis are analysed with relevant pathophysioloical consequences. In steady flow through the straight stenosed tube, excellent agreement between LES results for Re = 1000 and 2000 and the corresponding experimental results are found when the appropriate inlet perturbations are introduced. In the models with an upstream curved segment, no significant effect of spiral flow on any flow property is found for the investigated Reynolds numbers; spiral pattern disappears before the stenosis – which may be due the rigid wall used in the models and/or a steady flow at the inlet. The effects of the curved upstream model can be seen mainly in the maximum turbulent kinetic energy (TKE), the maximum pressure drop and the maximum wall shear stress (WSS), which in the curved upstream models generally increase significantly compared with the corresponding results in the straight stenosed tube. The maximumcontributions of the SGS motion to the large-scale motion in both non-spiral and spiral flow through a regular stenosis, an irregular stenosis and an irregular stenosis with an adjacent post-stenotic irregular aneurysm are 50%, 55%and 25%, respectively, for the highest Reynolds number investigated in each model. Although the wall pressure and shear stress obtained from the k-ω Transitional model agree quite well with the corresponding LES results, the turbulent results obtained from the k-ω Transitional model differ significantly from the corresponding LES results – this shows unsuitability of the k-ω model for pulsatile flow simulation. Large permanent recirculation regions are observed right after the stenosis throat in both non-spiral and spiral flow, which in the model of a stenosis with an adjacent post-stenotic aneurysm are stretched beyond the aneurysm and the length of the recirculation regions increases with spiral velocity. This study shows that, in both steady and unsteady pulsatile flow through the straight tube model having either a stenosis (regular or irregular) or an irregular stenosis with an adjacent post-stenotic irregular aneurysm, the TKE rises significantly at some locations and phases if a spiral effect is introduced at the inlet of the model. However, the maximum value of the TKE in a high spiral flow drops considerably compared with that in a low spiral flow. The maximum wall pressure drop and shear stress occur around the stenosis throat during all the phases of the pulsatile cycle. In the model of a stenosis only, the wall pressure rises in the immediate post-stenotic region after its drop at the stenosis throat. However, in the model of a stenosis with an adjacent aneurysm, the wall pressure does not rise to regain its undisturbed value before the start of the last quarter of the aneurysm. The effects of the spiral flow on the wall pressure and WSS are visible only in the downstream region where they take oscillatory pattern. The break frequencies of energy spectra for velocity and pressure fluctuations from −5/3 power slope to −10/3 power slope and −7/3 power slope, respectively, are observed in the downstream transition-to-turbulence region in both the non-spiral and spiral flow. At some locations in the transition region, the velocity spectra in the spiral flow has larger inertial subrange region than that in non-spiral flow. The effects of the spiral flow on the pressure spectra is insignificant. Also, the maximum wall pressure drop, the maximum WSS and the maximum TKE in the non-spiral flow through the irregular stenosis rise significantly compared with the corresponding results in the non-spiral flow through the regular stenosis. When the area reduction in the stenosis is increased, the maximum pressure drop, the maximumWSS and the TKE rise sharply. As for the effects of the length of the stenosis, the maximum WSS falls significantly and the maximum TKE rises sharply due to the increase in the length of the stenosis; but the maximum pressure drop is almost unaffected by the increase in the stenosis length.

Colorectal cancer (CRC) is the third most common cancer in the UK with 41,000 new cases diagnosed in 2011. Despite undergoing potentially curative resection, a significant amount of patients develop recurrence. Biomarkers that aid prognostication or identify patients who are suitable for adjuvant treatments are needed. The TNM staging system does a reasonably good job at offering prognostic information to the treating clinician, but it could be better and identifying methods of improving its accuracy are needed. Tumour progression is based on a complex relationship between tumour behaviour and the hosts’ inflammatory responses. Sustained tumour cell proliferation, evading growth suppressors, resisting apoptosis, replicative immortality, sustained angiogenesis, invasion & metastasis, avoiding immune destruction, deregulated cellular energetics, tumour promoting inflammation and genomic instability & mutation have been identified as hallmarks. These hallmarks are malignant behaviors are what makes the cell cancerous and the more extreme the behaviour the more aggressive the cancer the more likely the risk of a poor outcome. There are two primary genomic instability pathways: Microsatellite Instability (MSI) and Chromosomal Instability (CI) also referred to as Microsatellite Stability (MSS). Tumours arising by these pathways have a predilection for specific anatomical, histological and molecular biological features. It is possible that aberrant molecular expression of genes/proteins that promote malignant behaviors may also act as prognostic and predictive biomarkers, which may offer superior prognostic information to classical prognostic features. Cancer related inflammation has been described as a 7th hallmark of cancer. Despite the systemic inflammatory response (SIR) being associated with more aggressive malignant disease, infiltration by immune cells, particularly CD8+ lymphocytes, at the advancing edge of the tumour have been associated with improved outcome and tumour MSI. It remains unknown if the SIR is associated with tumour MSI and this requires further study. The mechanisms by which colorectal cancer cells locally invade through the bowel remain uncertain, but connective tissue degradation by matrix metalloproteinases (MMPs) such as MMP-9 have been implicated. MMP-9 has been found in the cancer cells, stromal cells and patient circulation. Although tumoural MMP-9 has been associated with poor survival, reports are conflicting and contain relatively small sample sizes. Furthermore, the influence of high serum MMP-9 on survival remains unknown. Src family kinases (SFKs) have been implicated in many adverse cancer cell behaviors. SFKs comprise 9 family members BLK, C-SRC, FGR, FYN, HCK, LCK, LYN, YES, YRK. C-SRC has been the most investigated of all SFKs, but the role of other SFKs in cellular behaviors and their prognostic value remains largely unknown. The development of Src inhibitors, such as Dasatinib, has identified SFKs as a potential therapeutic target for patients at higher risk of poor survival. Unfortunately, clinical trials so far have not been promising but this may reflect inadequate patient selection and SFKs may act as useful prognostic and predictive biomarkers. In chapter 3, the association between cancer related inflammation, tumour MSI, clinicopathological factors and survival was tested in two independent cohorts. A training cohort consisting of n=182 patients and a validation cohort of n=677 patients. MSI tumours were associated with a raised CRP (p=0.003). Hypoalbuminaemia was independently associated with poor overall survival in TNM stage II cancer (HR 3.04 (95% CI 1.44 – 6.43);p=0.004), poor recurrence free survival in TNM stage III cancer (HR 1.86 (95% 1.03 – 3.36);p=0.040) and poor overall survival in CI colorectal cancer (HR 1.49 (95% CI 1.06 – 2.10);p=0.022). Interestingly, MSI tumours were associated with poor overall survival in TNM stage III cancer (HR 2.20 (95% CI 1.10 – 4.37);p=0.025). In chapter 4, the role of MMP-9 in colorectal cancer progression and survival was examined. MMP-9 in the tissue was assessed using IHC and serum expression quantified using ELISA. Serum MMP-9 was associated with cancer cell expression (Spearman’s Correlation Coefficient (SCC) 0.393, p<0.001)) and stromal expression (SCC 0.319, p=0.002). Serum MMP-9 was associated with poor recurrence-free (HR 3.37 (95% CI 1.20 – 9.48);p=0.021) and overall survival (HR 3.16 (95% CI 1.22 – 8.15);p=0.018), but tumour MMP-9 was not survival or MSI status. In chapter 5, the role of SFK expression and activation in colorectal cancer progression and survival was studied. On PCR analysis, although LYN, C-SRC and YES were the most highly expressed, FGR and HCK had higher expression profiles as tumours progressed. Using IHC, raised cytoplasmic FAK (tyr 861) was independently associated with poor recurrence free survival in all cancers (HR 1.48 (95% CI 1.02 – 2.16);p=0.040) and CI cancers (HR 1.50 (95% CI 1.02 – 2.21);p=0.040). However, raised cytoplasmic HCK (HR 2.04 (95% CI 1.11 – 3.76);p=0.022) was independently associated with poor recurrence-free survival in TNM stage II cancers. T84 and HT29 cell lines were used to examine the cellular effects of Dasatinib. Cell viability was assessed using WST-1 assay and apoptosis assessed using an ELISA cell death detection assay. Dasatinib increased T84 tumour cell apoptosis in a dose dependent manner and resulted in reduced expression of nuclear (p=0.008) and cytoplasmic (p=0.016) FAK (tyr 861) expression and increased nuclear FGR expression (p=0.004). The results of this thesis confirm that colorectal cancer is a complex disease that represents several subtypes of cancer based on molecular biological behaviors. This thesis concentrated on features of the disease related to inflammation in terms of genetic and molecular characterisation. MSI cancers are closely associated with systemic inflammation but despite this observation, they retain their relatively improved survival. MMP-9 is a feature of tissue remodeling during inflammation and is also associated with degradation of connective tissue, advanced T-stage and poor outcome when measured in the serum. The lack of stromal quantification due to TMA use rather than full sections makes the value of tumoural MMP-9 immunoreactivity in the prognostication and its association with MSI unknown and requires further study. Finally, SFK activation was also associated with SIR, however, only cytoplasmic HCK was independently associated with poor survival in patients with TNM stage II disease, the group of patients where identifying a novel biomarker is most needed. There is still some way to go before these biomarkers are translated into clinical practice and future work needs to focus on obtaining a reliable and robust scientific technique with validation in an adequately powered independent cohort.

A typical absence is a non-convulsive epileptic seizure that is a sole symptom of childhood absence epilepsy (CAE). It is characterised by a generalised hyper-synchronous activity (2.5-5 Hz) of neurons in the thalamocortical network that manifests as a spike and slow-wave discharge (SWD) in the electroencephalogram. Although CAE is not a benign form of epilepsy, its physiological basis is not well understood. In an attempt to make progress regarding the mechanism of SWDs, I built a large-scale computational model of the thalamocortical network that replicated key cellular and network electric oscillatory behaviours. Model simulation indicated that there are multiple pathological pathways leading to SWDs. They fell into three categories depending on their network-level effects. Moreover, all SWDs had the same physiological mechanism of generation irrespective of their underlying pathology. They were initiated by an increase in NRT cell bursting prior to the SWD onset. SWDs critically depended on the T-type Ca2+ current (IT) mediated firing in NRT and higher-order thalamocortical relay cells (TCHO), as well as GABAB synaptic receptor-mediated IPSPs in TCHO cells. On the other hand, first-order thalamocortical cells were inhibited during SWDs and did not actively participate in their generation. These cells, however, could promote or disrupt SWD generation if they were hyperpolarised or depolarised, respectively. Importantly, only a minority of active TC cells with a small proportion of them bursting were necessary to ensure the SWD generation. In terms of their relationship to other brain rhythms, simulated SWDs were a product of NRT sleep spindle (6.5-14 Hz) and cortical δ (1-4 Hz) pacemakers and had their oscillation frequency settle between the preferred oscillation frequencies of the two pacemakers with the actual value depending on the cortical bursting intensity. These modelling results are discussed in terms of their implications for understanding CAE and its future research and treatment.

This current PhD Thesis in Neuropathology focuses on the development and assessment of in vitro simulation approaches to intracerebral haemorrhage. The PhD Thesis provides a clinical and experimental neuropathological overview of intracerebral haemorrhage as well as an account of the in vitro simulation approaches to the disease, before proceeding to the presentation of the experimental work designed and performed by the author. The development of the herein presented in vitro simulation approaches to intracerebral haemorrhage was based on the use of an immortalized embryonic murine hippocampal cell-line (mHippoE-14) and its response to oligomycin-A and ferrum or haemin under appropriately selected conditions (aiming to simulate the natural history of the disease in a more reliable manner). The PhD Thesis provides a characterization of the mHippoE-14 cell-line (through a real-time cellular response analysis and a cytomorphological characterization), before proceeding to the actual experimental justification of the conditions chosen for the development of the herein presented in vitro simulation approaches to intracerebral haemorrhage, and their assessment. The latter was performed through the undertaking of: (a) real-time cellular response analysis, (b) cytomorphological assessment, (c) profiling of neuronal markers’ expression, (d) neurochemical assessment, and (e) proteomic profiling. All experiments were performed at the University of Glasgow. The current PhD Thesis also provides a critical appraisal of: (a) the utility, novelty and limitations of the developed in vitro simulation approaches, and (b) the positioning of the developed in vitro simulation approaches within the neuropathopoietic context.

Adequate nutritional status promotes optimal structure and function. In PLWH, few studies on the impact of dietary intake on nutritional and metabolic status have been undertaken. This cross-sectional secondary data analysis examined how different dietary patterns influenced nutritional and metabolic integrity in asymptomatic PLWH in the North-West Province of South Africa. Dietary data were collected using validated QFFQ. Data analysis was by SPSS version 14. Dietary and nutrient patterns were generated using Principal Component Analysis. Though asymptomatic, marked biochemical differences depicting altered metabolism and inflammation were observed in PLWH compared to the uninfected. PLWH also showed an anthropometric profile that depicted altered body composition and abnormal fat distribution. Four dietary patterns: animal-based, ‘recommended’, staple, and the Carbohydrate, Vegetable and Legumes (CVL) based were observed in both PLWH and the uninfected with slight differences. In PLWH, the animal-based similar to the CVL pattern was associated with better overall nutrient intake (r=0.5, p<0.001) and selected nutrients, including energy (r=0.3, p<0.001), protein (r=0.6, p<0.001), iron (r=0.5, p<0.001), zinc (r=0.6, p<0.001) and vitamin A (r=0.5, p<0.001), compared to the other dietary patterns. The animal based dietary pattern also predicted higher BMI (OR=2.2, 95% CI=0.9-5.0), LBM (3.6, 1.3-10.4), serum albumin (1.5, 0.9-2.4) and lower liver enzymes AST (0.5, 0.3-0.8) and ALT (0.6, 0.4-0.9). Using Graphical Chain Modelling, higher intake of the animal-based but lower staple-based dietary patterns were associated with better overall nutrient intake, serum vitamins A, E, lipid score, albumin, BMI and LBM suggesting that intake of this diet may provide better nutrient quality, enhancing nutritional status and metabolic proficiency, which may ultimately influence disease progression. The findings have implications for dietary guidelines for this population but further research is required. However, if these findings are true, then a predominantly animal-based diet may be ‘recommended’ for this population. Moreover, the longer term implications of high fat intake associated with the animal based dietary pattern on obesity and associated risks should be considered. This poses a challenge to imperatively weigh up the longer term risks of the overall population profile crucial for public health.

The physicochemical nature of the infectious agent in prion diseases creates a significant challenge for decontamination services. It has been shown to be both resistant to standard methods of decontamination, used to inactivate viruses and bacteria, and to associate avidly with surgical stainless steel. Moreover, the pathophysiology of the variant, iatrogenic and sporadic forms of Creutzfeldt-Jakob Disease (CJD) suggests deposition of the infectious agent across a wide range of extraneural, lymphoid tissues, as well as in the skeletal muscle and blood. Coupled with the potential for asymptomatic carriers, there is a significant risk of iatrogenic transmission of CJD through both neurosurgical procedures and standard surgery. This PhD study was undertaken in order to improve methods of instrument decontamination and to evaluate prion detection techniques and their applicability for the assessment of prion inactivation and removal. The project has provided relevant, critical assessment of hospital decontamination procedures, in addition to guidance on how working protocols should be improved to provide a cleaner and safer end product for the patient. Moreover, laboratory studies have been performed to evaluate current methods of prion decontamination in the context of hospital procedures for instrument reprocessing. Challenges faced by sterile service departments, such as soil drying and surface degradation, have been addressed and their impact on the risk of iatrogenic transmission of prions has been investigated. Critically, the use of a fluorescent amyloid fluorophore for the detection of prionassociated amyloid as a marker for disease permitted the investigation of the role of amyloid in infectious disease under denaturing conditions. Correlation of this detection technique with the identification of PrPres by Western blot and infectious disease suggested that, whilst fluorescent detection of prion-associated amyloid was more sensitive than Western blot, PrPres detection was more specific relative to infectivity. Improved fluorophores, with greater sensitivity, have been evaluated which will enhance in situ detection of prions in the future.

Crackle sounds are associated with a variety of lung disorders. Smoking is also associated with many of the changes in the lung and airways leading to crackles. However, studying crackles as an indication of pathologic changes related to cigarette smoking in the lung is an underdeveloped area of research which needs to be explored. This study was undertaken to investigate whether differences in the crackles' characteristics (duration of two cycle deflection (2CD) and number of crackles per breathing cycle (NCBC)) in the lung of smoking and non-smoking young adults could be found and to quantify these differences, if present, using a digital stethoscope and computer aided lung sound analysis (CALSA). Sixty male subjects (30 smokers and 30 non-smokers) with an average age of 26.6 years (SD ± 4.7) were recruited, drawn from students at the University of Southampton in the United Kingdom. The lung sound data were recorded on one occasion using a digital stethoscope connected to a laptop running MATLAB to record and store the lung sounds from seven anatomical sites on the chest. The 2CD and NCBC per site in 25 second recordings were calculated using data from each of the anatomical sites used for recording lung sounds (excluding the trachea). No statistically significant differences in NCBC per site were found between smokers and non-smokers at any anatomical location. The 2CD per site data revealed some statistically significant differences at both anterior sites (anterior left: F (2, 57) = 9.40, P = 0.00; anterior right: F (2, 57) = 9.51, P = 0.00)) and both lateral sites (middle left: F (2, 57) = 4.2, P = 0.02; middle right: F (2, 57) = 4.36, P = 0.02)). The hypothesis that lung crackle’s 2CD differ between smokers and non-smokers has been supported but the hypothesis that NCBC differ between smokers and non-smokers has not been supported.