Kylie Mills

Characterization of the α1-adrenoceptor subtype mediating contractions of the pig internal anal sphincter

The internal anal sphincter has been shown to contract in response to α1‐adrenoceptor stimulation and therefore α1‐adrenoceptor agonists may be useful in treating faecal incontinence. This study characterizes the α1‐adrenoceptor subtype responsible for mediating contraction of the internal anal sphincter of the pig.

Alterations in acetylcholine, PGE2 and IL6 release from urothelial cells following treatment with pyocyanin and lipopolysaccharide

The effects of pseudomonal virulence factor pyocyanin, and LPS from Pseudomonas aeruginosa and Escherichia coli on urothelial mediator release and cytokine production were examined. RT4 urothelial cells were treated with pyocyanin (1-100 μM) or LPS (1-100 ng/mL) for 24-h. Effects were measured in terms of changes in cell viability, basal and stretch-induced acetylcholine (Ach) and PGE2 release, and inflammatory cytokines (IL-6 and IL-12) production. Twenty-four hour pyocyanin (100 μM) treatment significantly decreased urothelial cell viability, while stretch-induced Ach release response was inhibited. E. coli LPS (100 ng/mL) produced a similar response with an additional significant increase in basal Ach release. All three virulence factors significantly increased urothelial PGE2 release; under basal release for pyocyanin (100 μM), stretch-induced release for pseudomonal LPS (≥ 10 ng/mL) and both basal and stimulated release for E. coli LPS (≥ 10 ng/mL). IL-6 and IL-12 were not detected in control samples, however 24h treatment with pyocyanin (100 μM) or LPS (100 ng/mL) resulted in IL-6 release from urothelial cells. The changes in urothelial Ach and PGE2, and release of inflammatory cytokine IL-6 induced by exposure to the bacterial virulence factors may play a role in the symptoms of pain and urinary urgency experienced with urinary tract infections.

Three gaseous neurotransmitters, nitric oxide, carbon monoxide, and hydrogen sulfide, are involved in the neurogenic relaxation responses of the porcine internal anal sphincter

Background/Aims The internal anal sphincter (IAS) plays an important role in maintaining continence and a number of neurotransmitters are known to regulate IAS tone. The aim of this study was to determine the relative importance of the neurotransmitters involved in the relaxant and contractile responses of the porcine IAS. Methods Responses of isolated strips of IAS to electrical field stimulation (EFS) were obtained in the absence and presence of inhibitors of neurotransmitter systems. Results Contractile responses of the sphincter to EFS were unaffected by the muscarinic receptor antagonist, atropine (1 μM), but were almost completely abolished by the adrenergic neuron blocker guanethidine (10 μM). Contractile responses were also reduced (by 45% at 5 Hz, P < 0.01) following desensitisation of purinergic receptors with α,β-methylene-ATP (10 μM). In the presence of guanethidine, atropine, and α,β-methylene-ATP, the remaining relaxatory responses to EFS were examined. These responses were not altered by the cyclooxygenase inhibitor, indomethacin (5 μM), the vasoactive intestinal polypeptide receptor antagonist, [d-p-Cl-Phe6,Leu17]-vasoactive intestinal peptide (PheLeu-VIP; 100 nM), or the purinoceptor antagonists, 8-phenyltheophyline (P1 receptors) or suramin (P2 receptors). However, relaxation responses were reduced by Nω-nitro-L-arginine (L-NNA; 100 μM), an inhibitor of nitric oxide synthesis (40–50% reduction), zinc protoprophyrin IX (10 μM), an inhibitor of carbon monoxide synthesis (20–40% reduction), and also propargylglycine (30 μM) and aminooxyacetic acid (30 μM), inhibitors of hydrogen sulphide synthesis (15–20% reduction). Conclusions Stimulation of IAS efferent nerves releases excitatory and inhibitory neurotransmitters: noradrenaline is the predominant contractile transmitter with a smaller component from ATP, whilst 3 gases mediate relaxation responses to EFS, with the combined contributions being nitric oxide > carbon monoxide > hydrogen sulfide.

NKA enhances bladder afferent mechanosensitivity via urothelial and detrusor activation

Tachykinins are expressed within bladder-innervating sensory afferents and have been shown to generate detrusor contraction and trigger micturition. The release of tachykinins from these sensory afferents may also activate tachykinin receptors on the urothelium or sensory afferents directly. Here, we investigated the direct and indirect influence of tachykinins on mechanosensation by recording sensory signaling from the bladder during distension, urothelial transmitter release ex vivo, and direct responses to neurokinin A (NKA) on isolated mouse urothelial cells and bladder-innervating DRG neurons. Bath application of NKA induced concentration-dependent increases in bladder-afferent firing and intravesical pressure that were attenuated by nifedipine and by the NK2 receptor antagonist GR159897 (100 nM). Intravesical NKA significantly decreased bladder compliance but had no direct effect on mechanosensitivity to bladder distension (30 µl/min). GR159897 alone enhanced bladder compliance but had no effect on mechanosensation. Intravesical NKA enhanced both the amplitude and frequency of bladder micromotions during distension, which induced significant transient increases in afferent firing, and were abolished by GR159897. NKA increased intracellular calcium levels in primary urothelial cells but not bladder-innervating DRG neurons. Urothelial ATP release during bladder distention was unchanged in the presence of NKA, whereas acetylcholine levels were reduced. NKA-mediated activation of urothelial cells and enhancement of bladder micromotions are novel mechanisms for NK2 receptor-mediated modulation of bladder mechanosensation. These results suggest that NKA influences bladder afferent activity indirectly via changes in detrusor contraction and urothelial mediator release. Direct actions on sensory nerves are unlikely to contribute to the effects of NKA.

Cyclophosphamide and ifosfamide enhancement of bladder sensory nerve activity

Paul A James, Lara Petelin, Ian Campbell, Hugh Dawkins, Stephen Fox, Janet Hiller, Judy Kirk, Geoffrey Lindeman, Finlay Macrae, Lyon Mascarenhas, Julie McGaughran, Bettina Meiser, April Morrow, Cassandra Nichols, Nicholas Pachter, Christobel Saunders, Clare Scott, Nicola Poplawski, Letitia Thrupp, Alison Trainer, Robyn Ward, Mary-Anne Young, Gillian Mitchell

Can n-acetylcysteine or vitamin c protect human bladder urothelial cells from acrolein toxicity?

Background - Primary brain tumours are rare among adults, but patients often experience physical, cognitive, neurological and psychosocial morbidity. Research has documented high rates of unmet supportive care needs among subgroups, such as patients receiving specific treatments or those receiving palliative care, but the needs of patients in the period soon after diagnosis are not known. Aim - To describe the unmet supportive care needs of adults recently diagnosed with primary brain tumours and change in needs over the early diagnosis/treatment period. Methods - A representative population-based sample of 40 patients was recruited approximately three months after diagnosis through a state cancer registry in Queensland, Australia. Patients or carer proxies completed surveys of supportive care needs in six domains (physical/daily living, psychological, patient care and support, sexuality, health system and information needs, and brain tumour-specific needs) at baseline and three months later. Mean supportive care needs scores (scale 0-100, with higher scores indicating higher levels of need) were calculated and compared over time. Results - The highest mean supportive care needs score at each time point was for physical needs (baseline 47.9, SD 26.3), closely followed by psychological needs (baseline 45.8, SD 35.6). Mean scores for other domains ranged from 30.4 to 37.9. Mean scores in all domains except for sexuality significantly declined over time, with the greatest decline for the patient care and support needs domain (mean 15.9 point decrease). Conclusions - Adults with primary brain tumours experience high levels of unmet physical and psychological needs early in the disease trajectory. However, levels of needs, particularly for patient care, decline over time, perhaps with the completion of primary treatments. Further research is needed to confirm these findings in a larger sample and investigate reasons for the decline seen.Programme/Policy Process: Once a VHL develops its activities through a cooperative network of institutions which are users and producers of information, it was essential to structure such a network within the field of cancer control and develop a governance model that could allow its sustainable operation. The model is composed of Executive Secretary, Advisory Committee, Executive Committee and Responsibility Matrix. The institutions which are part of this collaborative network have been selected in order to represent the regional diversity present in Brazil and also the diverse profiles of institutions related to cancer control, such as research, academia, government, scientific societies and organizations representing patients.Background: Smoking rates in Aboriginal Australians are gradually reducing in some age groups, but not for people in the peak reproductive years.¹ Smoking cessation is vital for cancer prevention.² Many regional programs avoid the use of threat messages when targeting Australian Aboriginal smokers.³ Aim: To assess, for the first time, the responses of Aboriginal smokers, 18–45 years, to Risk Behaviour Diagnosis scales (RBD)⁴ and intentions to quit smoking, including gender differences. Methods: We interviewed 121 Aboriginal smokers, using a structured questionnaire including adapted RBD scales. The RBD measured perceived threat (susceptibility and severity of threat) and perceived efficacy (self-efficacy and response efficacy) on Likert scales. Intentions to quit were assessed. Scales were recoded into high-low responses. Face validity was assessed via an Aboriginal panel, and scales assessed for reliability. Chi-square tests investigated the associations between intention to quit, efficacy/threat and gender. Results: Among men, intention to quit was associated with perceived efficacy (X² = 15.23;df = 1; p < 0.0001), but not with perceived threat. For women, intention to quit was neither associated with efficacy nor threat. Both genders were more likely to have high intention to quit, with high efficacy and high threat (n = 54;45%:maleX² = 12.6;df = 1; p < 0.001:femaleX²= 5.6;df = 1; p < 0.05). There was no difference in intention to quit with low efficacy-high threat for either gender (n = 39;32%). In contrast, all of the men with low threat-high efficacy (n = 5;4%) intended to quit, whereas all of the women with low threat-low efficacy (n = 6;5%) intended to quit. Conclusions: High-perceived threat was associated with high intention to quit smoking only when perceived efficacy was high. Gender differences may be a consideration. The RBD scales could be used to tailor messages to the level of efficacy and threat in clinical consultations, and in regional programs. All Aboriginal Australian smokers may benefit from increased efficacy to quit smoking.Abstract presented at the 2014 World Cancer Congress, 3-6 December 2014, Melbourne, Australia

Chloroacetaldehyde, and not acrolein, is the more uro-toxic metabolite of cyclophosphamide and isofosfamide in vitro.

Hypothesis / aims of study Providing continence care is a common cause of sleep disruption for individuals living in residential aged care facilities. However little is known about what staff actually do when they provide continence care at night, how they balance residents’ needs for sleep and continence care, and the factors that inform their practice. The purpose of the study was to explore how residential aged care staff addressed residents’ dual needs for continence care and sleep at night, and the basis for their decisions about such care.Hypothesis / aims of study Men who undergo TURP are expected to experience improvement in flow rate as a result of the reduction in outlet resistance. Due to intrasubject variability in maximum flow rate (Qmax), this may not be apparent on conventional uroflowmetry (one flow measurement per subject before and after surgery). It should, however, be clearly demonstrable from home uroflowmetry, given that multiple measurements allow precise calculation of an average Qmax. Therefore, our aim was to demonstrate the effect of TURP on flow rate and voided volume (Vvoid) using home uroflowmetry.

Modulation of urothelial function and afferent sensitivity by neurokinin A

Hypothesis / aims of study Providing continence care is a common cause of sleep disruption for individuals living in residential aged care facilities. However little is known about what staff actually do when they provide continence care at night, how they balance residents’ needs for sleep and continence care, and the factors that inform their practice. The purpose of the study was to explore how residential aged care staff addressed residents’ dual needs for continence care and sleep at night, and the basis for their decisions about such care.Hypothesis / aims of study Men who undergo TURP are expected to experience improvement in flow rate as a result of the reduction in outlet resistance. Due to intrasubject variability in maximum flow rate (Qmax), this may not be apparent on conventional uroflowmetry (one flow measurement per subject before and after surgery). It should, however, be clearly demonstrable from home uroflowmetry, given that multiple measurements allow precise calculation of an average Qmax. Therefore, our aim was to demonstrate the effect of TURP on flow rate and voided volume (Vvoid) using home uroflowmetry.