Autologous chondrocyte implantation-derived synovial fluids display distinct responder and non-responder proteomic profiles

Hulme, Charlotte H. & Wilson, Emma L. - Equal contributorsBackground Autologous chondrocyte implantation (ACI) can be used in the treatment of focal cartilage injuries to prevent the onset of osteoarthritis (OA). However, we are yet to understand fully why some individuals do not respond well to this intervention. Identification of a reliable and accurate biomarker panel that can predict which patients are likely to respond well to ACI is needed in order to assign the patient to the most appropriate therapy. This study aimed to compare the baseline and mid-treatment proteomic profiles of synovial fluids (SFs) obtained from responders and non-responders to ACI. Methods SFs were derived from 14 ACI responders (mean Lysholm improvement of 33 (17–54)) and 13 non-responders (mean Lysholm decrease of 14 (4–46)) at the two stages of surgery (cartilage harvest and chondrocyte implantation). Label-free proteome profiling of dynamically compressed SFs was used to identify predictive markers of ACI success or failure and to investigate the biological pathways involved in the clinical response to ACI. Results Only 1 protein displayed a ≥2.0-fold differential abundance in the preclinical SF of ACI responders versus non-responders. However, there is a marked difference between these two groups with regard to their proteome shift in response to cartilage harvest, with 24 and 92 proteins showing ≥2.0-fold differential abundance between Stages I and II in responders and non-responders, respectively. Proteomic data has been uploaded to ProteomeXchange (identifier: PXD005220). We have validated two biologically relevant protein changes associated with this response, demonstrating that matrix metalloproteinase 1 was prominently elevated and S100 calcium binding protein A13 was reduced in response to cartilage harvest in non-responders. Conclusions The differential proteomic response to cartilage harvest noted in responders versus non-responders is completely novel. Our analyses suggest several pathways which appear to be altered in non-responders that are worthy of further investigation to elucidate the mechanisms of ACI failure. These protein changes highlight many putative biomarkers that may have potential for prediction of ACI treatment success

Dietary fibre for the newly weaned pig: Influences on pig performance, intestinal development and expression of experimental post-weaning colibacillosis and intestinal spirochaetosis

The diet fed in the immediate post-weaning phase influences the development of the intestinal tract and the establishment of microflora within the gut of the piglet. This development may prove beneficial to the long-term health of the pig or it may result in growth checks, diarrhoea and excessive growth of intestinal pathogens, depending on the diet fed and the stresses imposed upon the piglet. Post-weaning colibacillosis (PWC) is associated with excessive proliferation of enterotoxigenic Escherichia coli in the small intestine. These bacteria attach to enterocytes and release toxins that cause hypersecretory diarrhoea. Diarrhoea is accompanied by weight loss, anorexia, dehydration and eventually death if infection is severe. The pathogenesis of PWC is complex and multifactorial, and is heavily influenced by weaning-associated factors such as stress and the change in diet at weaning. The primary aim of this PhD study was to investigate the influence of dietary fibre on the intestinal and whole body development of healthy weaner pigs and pigs with experimental PWC. The latter animals were used to investigate the influence of fibre on the incidence of diarrhoea and the proliferation of pathogenic intestinal E. coli in experimentally infected pigs. Physiologically, the term dietary fibre includes any plant polysaccharides that are resistant to digestion in the small intestine, instead passing into the large intestine where they are fermented. The negative control diet used in all experiments contained cooked white rice as the main ingredient because it is very low in fibre content and is highly digestible. Sources of fibre were added into this diet to create the desired level and type of dietary fibre. In experiments 2, 3 and 4, a hydrolysed rice diet was also tested as a base rice ingredient. As different facilities were used for healthy and experimental infection experiments, Chapter 3 addressed the issue of food intake with regard to the design of experiments within the project. The remainder of the thesis was divided into sections based on the particular type of dietary fibre that was being targeted. Typically, pigs were killed 1-3 weeks after weaning, and intestinal and whole body measurements made. Dietary sources of primarily insoluble fibre were first examined, followed by sources of soluble fibre, and finally purified viscous soluble sources of fibre. Each of these areas was explored with regard to the intestinal and whole body development of the healthy pig before investigating how the type of fibre affected pigs with experimental PWC. As an extension of this work to other intestinal infections, the influence of dietary soluble viscous fibre on the pathogenesis of porcine intestinal spirochaetosis (PIS), a post-weaning large intestinal infection caused by the spirochaete Brachyspira pilosicoli, was also tested. In the healthy newly weaned pig there was rapid adaptation to the presence of increasing amounts of dietary fibre. Sources of insoluble fibre, particularly wheat and lupins, had the greatest effect on increasing the size of the large intestine and on increasing microbial fermentation, although the addition of soluble fibre (pearl barley) also was capable of significantly increasing large intestinal size and fermentative capacity compared to the base rice diet. As a result of feeding fibre sources, the carcase growth tended to suffer at the expense of intestinal growth, although all pigs expended energy into intestinal growth in the immediate post-weaning period. The ileal digestibility of nutrients at 10 days post-weaning was depressed by addition of fibre to the diet. The digestibility of crude protein and gross energy at the ileum decreased upon addition of insoluble fibre from lupins, and upon addition of resistant starch, whilst addition of pearl barley (soluble fibre) reduced the starch digestibility. The interaction of diet with the development and expression of PWC differed according to the diet fed. Inoculation with enterotoxigenic E. coli generally reduced the whole body and intestinal growth and intestinal fermentation of all pigs, although the pigs fed the cooked white rice diet suffered the least depression in growth and consistently had drier faeces throughout all trials. Raw wheat, as a primary dietary ingredient and source of insoluble fibre and resistant starch, did not significantly alter the proliferation of intestinal enterotoxigenic E. coli. However, extrusion of the wheat resulted in an increase in the proliferation of E. coli, as did hydrolysing the rice. Addition of pearl barley (soluble fibre source) to the cooked rice diet significantly increased the proliferation of enterotoxigenic E. coli as well as increasing the viscosity of the intestinal contents of healthy and experimentally infected pigs. Feeding a diet containing the viscous, purified polysaccharide carboxymethylcellulose (CMC) at 4% of the diet induced a natural infection of PWC without requiring experimental inoculation with enterotoxigenic E. coli. This effect was repeatable in the immediate post-weaning period but did not occur a few weeks after weaning. This study showed that dietary fibre affects the rate of development of the intestines and the pig’s ability to utilise dietary nutrients immediately after weaning. Although increasing the amount of dietary fibre was not always detrimental to the live weight growth of the pig, the experimentally infected pigs fed the cooked rice diet (low fibre) were the only infected animals to maintain positive growth rates. The expression of PWC was increased by the addition of soluble fibre and by increasing the viscosity of the intestinal contents. This work illustrates the complex interaction of diet with the microflora of the pig’s intestinal tract, and suggests that a highly digestible, low fibre diet may be most suitable for growth and prevention of intestinal disorders in the first one to two weeks following weaning

Characterisation of hypertension in a new model of PKD in rats

1 page(s

Factor structure and construct validity of the eating disorder examination-questionnaire in college students: Further support for a modified brief version

Objective: The Eating Disorder Examination-Questionnaire (EDE-Q) is widely used in research studies across clinical and nonclinical groups. Relatively little is known about psychometric properties of this measure and the available literature has not supported the proposed scale structure. This study evaluated the factor structure and construct validity of the EDE-Q in a nonclinical study group of young adults. Method: Participants were 801 young adults (573 females and 228 males) enrolled at a large public university in the Midwestern United States who completed the EDE-Q and a battery of behavioral and psychological measures. Results: Confirmatory factor analysis (CFA) revealed an inadequate fit for the original EDE-Q structure but revealed a good fit for an alternative structure suggested by recent research with predominately overweight/obese samples. CFA supported a modified seven-item, three-factor structure; the three factors were interpreted as dietary restraint, shape/weight overvaluation, and body dissatisfaction. Factor loadings and item intercepts were invariant across sex and overweight status. The three factors had less redundancy than the original EDE-Q scales and demonstrated improved convergent and discriminant validity in relation to relevant other measures. Discussion: These factor-analytic findings, which replicate findings from studies with diverse predominately overweight/obese samples, supported a modified seven-item, three-factor structure for the EDE-Q with improved psychometric characteristics. The findings provide further empirical support for the distinction between body dissatisfaction and overvaluation and have implications for assessment and research. These findings need to be replicated in samples of persons with eating-disorder psychopathology including those with anorexia nervosa, bulimia nervosa, and allied states

Temporal relationship between renal cyst development, hypertension and cardiac hypertrophy in a new rat model of autosomal recessive polycystic kidney disease

Background/Methods: We have examined the hypothesis that cyst formation is key in the pathogenesis of cardiovascular disease in a Lewis polycystic kidney (LPK) model of autosomal-recessive polycystic kidney disease (ARPKD), by determining the relationship between cyst development and indices of renal function and cardiovascular disease. Results: In the LPK (n = 35), cysts appear at week 3 (1.1 ± 0.1 mm) increasing to week 24 (2.8 ± 2 mm). Immunostaining for nephron-specific segments indicate cysts develop predominantly from the collecting duct. Cyst formation preceded hypertension (160 ± 22 vs. Lewis control 105 ± 20 mm Hg systolic blood pressure (BP), n = 12) at week 6, elevated creatinine (109 ± 63 vs. 59 ± 6 μmol/l, n = 16) and cardiac mass (0.7 vs. 0.4% bodyweight, n = 15) at week 12, and left ventricular hypertrophy (2,898 ± 207 vs. 1,808 ± 192 μm, n = 14) at week 24 (all p ≤ 0.05). Plasma-renin activity and angiotensin II were reduced in 10- to 12-week LPK (2.2 ± 2.9 vs. Lewis 11.9 ± 4.9 ng/ml/h, and 25.0 ± 19.1 vs. 94.9 ± 64.4 pg/ml, respectively, n = 26, p ≤ 0.05). Ganglionic blockade (hexamethonium 3.3 mg/kg) significantly reduced mean BP in the LPK (52 vs. Lewis 4%, n = 9, p ≤ 0.05). Conclusion: Cyst formation is a key event in the genesis of hypertension while the sympathetic nervous system is important in the maintenance of hypertension in this model of ARPKD

Age dependent response to anti-hypertensive therapy in a new model of rat polycystic kidney disease

2 page(s

Impacts of familiarity, conflict, and sex on continuous interpersonal behavior

Examines impacts of familiarity, conflict, and sex on continuously assessed behavior in dyadic interactions using the Continuous Assessment of Interpersonal Dynamics across several samples. Establishes norms and basic psychometrics for CAID while also informing factors that influence interpersonal behavior