Salvage Abdominoperineal Resection for Locally Recurrent or Persistent Anal Squamous Cell Carcinoma after Definitive Chemoradiation

PURPOSE/OBJECTIVE(S)

Initial treatment for patients with squamous cell carcinoma of the anal canal includes definitive chemoradiation. Salvage abdominoperineal resection (APR) is the treatment of choice for recurrent or persistent disease. Older studies suggest approximately 50% successful salvage of recurrent or persistent disease with APR. Risk factors for failure after salvage APR are incompletely characterized.

MATERIALS/METHODS

Using a single institutional database, patients were identified who underwent salvage APR after definitive intensity-modulated radiotherapy-based chemoradiation between 2003 and 2022. Clinical and pathologic variables analyzed included age at APR, sex, race, HIV status, initial cT stage, initial cN stage, radiation dose, recurrent vs persistent disease, recurrent pT stage, recurrent pN stage, the presence of LVSI, PNI or <2mm surgical margins, and the use of either intraoperative radiation or another treatment modality in addition to APR. The log rank test was used to determine differences in time from APR to events (local recurrence, distant metastasis and death) based on clinical and pathologic variables. The Cox Proportional Hazard Model was used to perform multivariable analysis for all factors with a univariate P-value <0.1.

RESULTS

Of 628 patients with anal squamous cell carcinoma, 50 (8.0%) were treated with abdominoperineal resection for locally recurrent (n = 29, 58%) or locally persistent (n = 21, 42%) disease. Median [interquartile range] follow up was 40.0 months [15.2-68.0 months] from APR. Median local recurrence-free survival was not reached; 1- and 2-year local recurrence-free survival was 81% (95% CI 72-92%) and 76% (64-89%). On multivariable analysis, pathologic T-stage of the recurrence (3.85 (1.07-13.9); P = .040), the presence of lymphovascular space invasion (9.1 (1.12-73.62); P = .038) and surgical margins <2mm (8.81 (2.11-36.73); P = .003) were all significantly associated with higher rates of local recurrence. Median distant metastasis-free survival was not reached; 1- and 2-year distant metastasis-free survival was 88% (81-98%) and 79% (67-92%). On multivariable analysis, only persistent (versus recurrent) local disease was significantly associated with higher rates of distant metastasis (1.23 (1.05-5.55) P = .043). Median overall survival was not reached; 1- and 2-year overall survival was 90% (81-98%) and 78% (65-90%). On multivariable analysis, only recurrent pT stage (T3/4 vs T1/2) was associated with higher rates of death (5.87 (1.02-33.65); P = .047).

CONCLUSION

APR is a successful salvage modality for anal squamous cell carcinoma with recurrent or persistent disease after chemoradiation results. Patients with pT3/4 disease, lymphovascular space invasion, surgical margins <2 mm may be associated with higher re-recurrence rates and may benefit from more frequent monitoring or treatment escalation.

Outcomes and after Hyperfractionated, Accelerated Reirradiation for Recurrent Anal Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

Abdominoperineal resection (APR) is the standard salvage treatment for recurrent or persistent squamous cell carcinoma of the anus (SCCA). However, reirradiation (reRT) can be used preoperatively or for those who are not candidates for surgery.

MATERIALS/METHODS

Using a single institutional database, patients were identified who underwent reRT for SCCA from 2003 to 2022. Response to reRT and outcomes after reRT were recorded. Variables analyzed included age at reRT, sex, reason for reRT (recurrent SCCA vs new SCCA after pelvic radiation for a different malignancy), interval between initial radiation and reRT, reRT dose, concurrent chemotherapy, receipt of APR and the presence of distant metastases at the time of reRT. Cox Proportional Hazard Model was used; multivariable analysis for all factors with a univariate P-value <0.1 on univariable analysis.

RESULTS

A total of 42 patients received reRT, which consisted of 1.5 Gray (Gy) twice daily fractions with ≥6-hour interval to a total dose ranging 30Gy to 54Gy (median [IQR] 39Gy [39-42Gy]. Thirty-eight patients (90.5%) received concurrent chemotherapy; most often with weekly cisplatin and 5-fluorouracil (N = 23, 54.8%). Median [IQR] follow-up after reRT was 11.4 months [4.9-40.8 months]. Median [IQR] initial radiation dose was 54Gy [54-58Gy], and median [IQR] interval between initial radiation and reRT was 3.6 years [2.1-6.0 years]. For 8 patients (19.1%), the initial radiation was given for a different pelvic malignancy prior to being diagnosed with SCCA. Four of these patients received brachytherapy alone or in conjunction with external beam. For the remaining 34 patients, the initial radiation was for SCCA and the reRT was for recurrent SCCA either in the anal canal (N = 23, 67.6%) or regional nodes (N = 11, 32.3%). Four patients (9.5%) had distant disease at the time of reRT. Eleven patients (26.2%) had planned APR after preoperative reRT; 1 patient had a pathologic complete response (pCR), 2 patients had a near pCR (<5% viable cancer). Twenty-nine patients (69.0%) were treated with reRT alone; 15 (51.7%) attained a clinical CR. Two patients (4.8%) were treated with palliative intent and response was not assessed. Median local recurrence free survival (LRFS) was 9.9 months; 2- and 3-year LRFS were both 41%. Median distant metastasis free survival (DMFS) was 11.8 months; 2- and 3-year DMFS were 38% and 34%, respectively. Median overall survival (OS) was 40.5 months; 2- and 3-year OS were 54% and 51%, respectively. On multivariable analysis, only the presence of distant disease at the time of reRT was significantly associated with worse LRFS (HR (95% CI) 4.14 (1.34-12.81); P = .014), worse DMFS (4.06 (1.37-12.06); P = .012) and worse OS (5.73 (1.57-20.9); P = .008).

CONCLUSION

ReRT is an option for patients presenting with either recurrent SCCA or new SCCA after prior pelvic radiation for a different malignancy. ReRT can be given prior to planned salvage APR or alone for patients who are not surgical candidates with an approximate 50% cCR rate.

Cat: Empirical modelling of Felis catus population dynamics in the UK

Domestic cats are popular companion animals, however not all live in human homes and many cats live within shelters or as free-roaming, unowned- feral or stray cats. Cats can transition between these subpopulations, but the influence of this connectivity on overall population dynamics, and the effectiveness of management interventions, remain poorly understood. We developed a UK-focused multistate Matrix Population Model (MPM), combining multiple life history parameters into an integrated model of cat demography and population dynamics. The model characterises cats according to their age, subpopulation and reproductive status, resulting in a 28-state model. We account for density-dependence, seasonality and uncertainty in our modelled projections. Through simulations, we examine the model by testing the effect of different female owned-cat neutering scenarios over a 10-year projection timespan. We also use the model to identify the vital rates to which total population growth is most sensitive. The current model framework demonstrates that increased prevalence of neutering within the owned cat subpopulation influences the population dynamics of all subpopulations. Further simulations find that neutering owned cats younger is sufficient to reduce overall population growth rate, regardless of the overall neutering prevalence. Population growth rate is most influenced by owned cat survival and fecundity. Owned cats, which made up the majority of our modelled population, have the most influence on overall population dynamics, followed by stray, feral and then shelter cats. Due to the importance of owned-cat parameters within the current model framework, we find cat population dynamics are most sensitive to shifts in owned cat husbandry. Our results provide a first evaluation of the demography of the domestic cat population in the UK and provide the first structured population model of its kind, thus contributing to a wider understanding of the importance of modelling connectivity between subpopulations. Through example scenarios we highlight the importance of studying domestic cat populations in their entirety to better understand factors influencing their dynamics and to guide management planning. The model provides a theoretical framework for further development, tailoring to specific geographies and experimental investigation of management interventions.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Evaluation of a brief video intervention aimed at UK-based veterinary surgeons to encourage neutering cats at four months old: A randomised controlled trial

In the UK, it is currently recommended that owned cats be neutered from four months of age. However, its uptake is inconsistent across the veterinary profession. Here we assess the effect of a brief video intervention that aimed to encourage four month neutering, whilst preserving clinical autonomy. We compare this theory-driven approach with traditional information giving and a control group. Veterinary surgeons who regularly undertook feline neutering work in the UK but did not routinely neuter cats at four months and/or recommend four month neutering for client owned cats were randomised into three groups (n = 234). Participants received either no information, a written summary of evidence or the video. The primary behaviour outcomes were the recommending and carrying out of neutering cats at four months. Evaluative, belief and stages of change measures were also collected. Self-reported outcomes were assessed pre-intervention, immediately post-intervention, two months post-intervention and six months post-intervention. At two months, participants that had received the video intervention were significantly more likely to have started recommending neutering cats at four months. At six months, participants that had received the video intervention were significantly more likely to have started carrying out neutering cats at four months. There were no significant behaviour changes for the other groups. At two months, the video intervention was associated with a significant increase in thinking about, and speaking to colleagues about, four-month neutering, relative to the control group. The written summary of evidence had no similar effect on stages of change, despite it being perceived as a significantly more helpful resource relative to the video. To conclude, a brief one-off video intervention resulted in an increase in positive behaviours towards neutering cats at 4 months, likely mediated by the social influences of the intervention prompting the opportunity to reflect and discuss four-month neutering with colleagues.

MOP and NOP receptor interaction: Studies with a dual expression system and bivalent peptide ligands

Opioids targeting mu;μ (MOP) receptors produce analgesia in the peri-operative period and palliative care. They also produce side effects including respiratory depression, tolerance/dependence and addiction. The N/OFQ opioid receptor (NOP) also produces analgesia but is devoid of the major MOP side effects. Evidence exists for MOP-NOP interaction and mixed MOP-NOP ligands produce analgesia with reduced side effects. We have generated a HEK_MOP/NOP human expression system and used bivalent MOP-NOP and fluorescent ligands to (i) probe for receptor interaction and (ii) consequences of that interaction. We used HEK_MOP/NOP cells and two bivalent ligands; Dermorphin-N/OFQ (MOP agonist-NOP agonist; DeNO) and Dermorphin-UFP101 (MOP agonist-NOP antagonist; De101). We have determined receptor binding profiles, GTPγ[³⁵S] binding, cAMP formation and ERK1/2 activation. We have also probed MOP and NOP receptor interactions in HEK cells and hippocampal neurones using the novel MOP fluorescent ligand, Dermorphin_ATTO488 and the NOP fluorescent ligand N/OFQ_ATTO594. In HEK_MOP/NOP MOP ligands displaced NOP binding and NOP ligands displaced MOP binding. Using fluorescent probes in HEK_MOP/NOP cells we demonstrated MOP-NOP probe overlap and a FRET signal indicating co-localisation. MOP-NOP were also co-localised in hippocampal tissue. In GTPγ[³⁵S] and cAMP assays NOP stimulation shifted the response to MOP rightwards. At ERK1/2 the response to bivalent ligands generally peaked later. We provide evidence for MOP-NOP interaction in recombinant and native tissue. NOP activation reduces responsiveness of MOP activation; this was shown with conventional and bivalent ligands.

Contrasting practices and opinions of UK-based veterinary surgeons around neutering cats at four months old

BACKGROUND

Many cats in the UK are not neutered before reaching potential breeding age. The purpose of this investigation was to understand the prevalence of veterinarians' behaviours around neutering cats at four months of age and to identify any needs of the veterinary profession on this.

METHODS

A sample of 483 veterinarians that completed a cross-sectional online questionnaire were included in quantitative and qualitative analyses.

RESULTS

Almost 70 per cent of veterinarians indicated they were comfortable carrying out neutering on cats of four months of age, and approximately half of veterinarians indicated they would recommend neutering client-owned cats at four months of age if practice policy permitted. There was no association found between these practices and geographic risk factors. Instead, neutering at four months was associated with the gender of the veterinarian, their practice policy and whether they routinely neuter unowned cats. Veterinarians have contrasting beliefs on similar themes, depending on whether they neuter kittens at four months or not, including differing opinions on general anaesthetic, surgery risks, owner compliance and their perceptions of neutering practices within the wider profession.

CONCLUSION

Familiarity and experience with the procedure, alongside perceived norms, are central to beliefs. We also highlight informational and learning barriers.

"I don't want to be a patient": Peer mentoring partnership fosters communication for autistic university students

Background: Despite recognition of the benefits of post-school education in improving life outcomes for autistic adults their university completion rates remain low.Aim: To explore the experiences of undergraduate autistic university students participating in specialist peer mentoring (SPM) to identify active ingredients in the peer mentoring process and to examine the impact of SPM on social communication.Material and method: A total of 30 (8 female; M age = 22.3; SD = 6.7) undergraduate autistic university students engaged in SPM participated in this study. A quantitative pre-test post-test design examined changes in autistic traits. In parallel, the experiences of participating in SPM were explored through semi-structured interviews.Results: Improvements were noted at post-test on the Social Responsiveness Scale-2 total score p = 0.02), and its Social Communication, (p = 0.03) and Social Motivation (p = 0.03) sub-scales. Four themes emerged from the interviews: Developing Partnership and Understanding, Modelling and Practising Communication, Psychological Support and Grading and Planning Skills.Conclusions: These results indicated that the mentor-mentee partnership was a crucial active ingredient of SPM. This partnership appeared to modify social cognition and motivation for autistic university students through modelling and practising communication.Significance: These results demonstrate that SPM can support participation at university for autistic university students.

Determination of Total Taurine in Pet Foods by Liquid Chromatography of the Dansyl Derivative: Collaborative Study

A liquid chromatographic (LC) method for the determination of total taurine in pet foods was evaluated in a collaborative study. Ten laboratories assayed 6 blind duplicate pairs of wet and dry pet foods. The taurine in the 6 sample pairs ranged from low (170 mg/kg) to high (2250 mg/kg) concentrations as is. Collaborators also assayed a sample of known taurine concentration for familiarization purposes. Samples were hydrolyzed to release bound taurine, which was subsequently converted to the dansyl derivative and quantitated by gradient-elution LC with fluorescence detection. Repeatability relative standard deviations, RSDr, ranged from 3.2 to 10.0%; reproducibility relative standard deviations, RSDR, ranged from 6.1 to 16.1%. The method has been adopted Official First Action status by AOAC INTERNATIONAL.

Combination of flow cytometry and functional imaging for monitoring of residual disease in myeloma

The iliac crest is the sampling site for minimal residual disease (MRD) monitoring in multiple myeloma (MM). However, the disease distribution is often heterogeneous, and imaging can be used to complement MRD detection at a single site. We have investigated patients in complete remission (CR) during first-line or salvage therapy for whom MRD flow cytometry and the two imaging modalities positron emission tomography (PET) and diffusion-weighted magnetic resonance imaging (DW-MRI) were performed at the onset of CR. Residual focal lesions (FLs), detectable in 24% of first-line patients, were associated with short progression-free survival (PFS), with DW-MRI detecting disease in more patients. In some patients, FLs were only PET positive, indicating that the two approaches are complementary. Combining MRD and imaging improved prediction of outcome, with double-negative and double-positive features defining groups with excellent and dismal PFS, respectively. FLs were a rare event (12%) in first-line MRD-negative CR patients. In contrast, patients achieving an MRD-negative CR during salvage therapy frequently had FLs (50%). Multi-region sequencing and imaging in an MRD-negative patient showed persistence of spatially separated clones. In conclusion, we show that DW-MRI is a promising tool for monitoring residual disease that complements PET and should be combined with MRD.

Rationale and development of a business case for antimicrobial stewardship programs in acute care hospital settings

Background

Antimicrobial stewardship programs (ASPs) have been shown to reduce inappropriate antimicrobial use and its consequences. However, these programs lack legislative requirements in many places and it can be difficult to determine what human resources are required for these programs and how to create a business case to present to hospital administrators for program funding. The objectives of the current paper were to review legislative requirements and outline human resource requirements for ASPs, and to create a base business case for ASPs.

Methods

A working group of antimicrobial stewardship experts from across Canada met to discuss the necessary components for creation of a business case for antimicrobial stewardship. A narrative review of the literature of the regulatory requirements and human resource recommendations for ASPs was conducted. Informed by the review and using a consensus decision-making process, the expert working group developed human resource recommendations based on a 1000 bed acute care health care facility in Canada. A spreadsheet based business case model for ASPs was also created.

Results

Legislative and /or regulatory requirements for ASPs were found in 2 countries and one state jurisdiction. The literature review and consensus development process recommended the following minimum human resources complement: 1 physician, 3 pharmacists, 0.5 program administrative and coordination support, and 0.4 data analyst support as full time equivalents (FTEs) per 1000 acute care beds. Necessary components for the business case model, including the human resource requirements, were determined to create a spreadsheet based model.

Conclusions

There is evidence to support the negative outcomes of inappropriate antimicrobial use as well as the benefits of ASPs. Legislative and /or regulatory requirements for ASPs are not common. The available evidence for human resource recommendations for ASPs using a narrative review process was examined and a base business case modelling scenario was created. As regulatory requirements for ASPs increase, it will be necessary to create accurate business cases for ASPs in order to obtain the necessary funding to render these programs successful.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0396-z) contains supplementary material, which is available to authorized users.

In vitro and in vivo characterization of the bifunctional μ and δ opioid receptor ligand UFP-505

BACKGROUND AND PURPOSE

Targeting more than one opioid receptor type simultaneously may have analgesic advantages in reducing side-effects. We have evaluated the mixed μ opioid receptor agonist/ δ opioid receptor antagonist UFP-505 in vitro and in vivo.

EXPERIMENTAL APPROACH

We measured receptor density and function in single μ, δ and μ /δ receptor double expression systems. GTPγ35 S binding, cAMP formation and arrestin recruitment were measured. Antinociceptive activity was measured in vivo using tail withdrawal and paw pressure tests following acute and chronic treatment. In some experiments, we collected tissues to measure receptor densities.

KEY RESULTS

UFP-505 bound to μ receptors with full agonist activity and to δ receptors as a low efficacy partial agonist At μ, but not δ receptors, UFP-505 binding recruited arrestin. Unlike morphine, UFP-505 treatment internalized μ receptors and there was some evidence for internalization of δ receptors. Similar data were obtained in a μ /δ receptor double expression system. In rats, acute UFP-505 or morphine, injected intrathecally, was antinociceptive. In tissues harvested from these experiments, μ and δ receptor density was decreased after UFP-505 but not morphine treatment, in agreement with in vitro data. Both morphine and UFP-505 induced significant tolerance.

CONCLUSIONS AND IMPLICATIONS

In this study, UFP-505 behaved as a full agonist at μ receptors with variable activity at δ receptors. This bifunctional compound was antinociceptive in rats after intrathecal administration. In this model, dual targeting provided no advantages in terms of tolerance liability.

LINKED ARTICLES

This article is part of a themed section on Emerging Areas of Opioid Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.14/issuetoc.

Dietary factors and pediatric multiple sclerosis: A case-control study

BACKGROUND

The role of diet in multiple sclerosis (MS) is largely uncharacterized, particularly as it pertains to pediatric-onset disease.

OBJECTIVE

To determine the association between dietary factors and MS in children.

METHODS

Pediatric MS patients and controls were recruited from 16 US centers (MS or clinically isolated syndrome onset before age 18, <4 years from symptom onset and at least 2 silent lesions on magnetic resonance imaging). The validated Block Kids Food Screener questionnaire was administered 2011-2016. Chi-squared test compared categorical variables, Kruskal-Wallis test compared continuous variables, and multivariable logistic regression analysis was performed.

RESULTS

In total, 312 cases and 456 controls were included (mean ages 15.1 and 14.4 years). In unadjusted analyses, there was no difference in intake of fats, proteins, carbohydrates, sugars, fruits, or vegetables. Dietary iron was lower in cases ( p = 0.04), and cases were more likely to consume below recommended guidelines of iron (77.2% of cases vs 62.9% of controls, p < 0.001). In multivariable analysis, iron consumption below recommended guidelines was associated with MS (odds ratio = 1.80, p < 0.01).

CONCLUSION

Pediatric MS cases may be less likely to consume sufficient iron compared to controls, and this warrants broader study to characterize a temporal relationship. No other significant difference in intake of most dietary factors was found.

Impact of early palliative care on caregivers of patients with advanced cancer: cluster randomised trial

Background

Early palliative care improves the quality of life (QoL) and satisfaction with care of patients with advanced cancer, but little is known about its effect on caregivers. Here, we report outcomes of caregiver satisfaction with care and QoL from a trial of early palliative care.

Patients and methods

Twenty-four medical oncology clinics were cluster-randomised, stratified by tumour site (lung, gastrointestinal, genitourinary, breast and gynaecological), to early palliative care team referral, or to standard oncology care with palliative care only as needed. Caregivers of patients with advanced cancer (clinical prognosis of 6-24 months, Eastern Cooperative Oncology Group 0-2) in both trial arms completed validated measures assessing satisfaction with care (FAMCARE-19) and QoL [SF-36v2 Health Survey; Caregiver QoL-Cancer (CQoL-C)], at baseline and monthly for 4 months. We used a multilevel linear random-intercept mixed-effect model to test whether there was improvement in the intervention group relative to the control group over 3 and 4 months.

Results

A total of 182 caregivers completed baseline measures (94 intervention, 88 control); 151 caregivers (77 intervention, 74 control) completed at least one follow-up assessment. Satisfaction with care improved in the palliative intervention group compared with controls over 3 months (P = 0.007) and 4 months (P = 0.02). There was no significant improvement in the intervention group compared with controls for CQoL-C (3 months: P = 0.92, 4 months: P = 0.51), Physical Component Summary of the SF-36v2 Health Survey (3 months: P = 0.83, 4 months: P = 0.20), or Mental Component Summary of the SF-36v2 Health Survey (3 months: P = 0.87, 4 months: P = 0.60).

Conclusion

Early palliative care increased satisfaction with care in caregivers of patients with advanced cancer.

ClinicalTrials.gov identifier

NCT01248624.

From science to action: Principles for undertaking environmental research that enables knowledge exchange and evidence-based decision-making

Effective conservation requires knowledge exchange among scientists and decision-makers to enable learning and support evidence-based decision-making. Efforts to improve knowledge exchange have been hindered by a paucity of empirically-grounded guidance to help scientists and practitioners design and implement research programs that actively facilitate knowledge exchange. To address this, we evaluated the Ningaloo Research Program (NRP), which was designed to generate new scientific knowledge to support evidence-based decisions about the management of the Ningaloo Marine Park in north-western Australia. Specifically, we evaluated (1) outcomes of the NRP, including the extent to which new knowledge informed management decisions; (2) the barriers that prevented knowledge exchange among scientists and managers; (3) the key requirements for improving knowledge exchange processes in the future; and (4) the core capacities that are required to support knowledge exchange processes. While the NRP generated expansive and multidisciplinary science outputs directly relevant to the management of the Ningaloo Marine Park, decision-makers are largely unaware of this knowledge and little has been integrated into decision-making processes. A range of barriers prevented efficient and effective knowledge exchange among scientists and decision-makers including cultural differences among the groups, institutional barriers within decision-making agencies, scientific outputs that were not translated for decision-makers and poor alignment between research design and actual knowledge needs. We identify a set of principles to be implemented routinely as part of any applied research program, including; (i) stakeholder mapping prior to the commencement of research programs to identify all stakeholders, (ii) research questions to be co-developed with stakeholders, (iii) implementation of participatory research approaches, (iv) use of a knowledge broker, and (v) tailored knowledge management systems. Finally, we articulate the individual, institutional and financial capacities that must be developed to underpin successful knowledge exchange strategies.

Evidence for nociceptin/orphanin FQ (NOP) but not µ (MOP), δ (DOP) or κ (KOP) opioid receptor mRNA in whole human blood

BACKGROUND

While it is well known that opioids depress the immune system, the site(s) of action for this depression is highly controversial. Immune modulation could occur directly at the immune cell or centrally via the hypothalamic-pituitary-adrenal axis. In a number of studies using individual enriched immune cell populations we have failed to detect classical µ (MOP), δ (DOP) and κ (KOP) receptors. The non-classical nociceptin/orphanin FQ (N/OFQ) receptor (NOP) is expressed on all cells examined thus far. Our hypothesis was that immune cells do not express classical opioid receptors and that using whole blood would definitively answer this question.

METHODS

Whole blood (containing all immune cell types) was incubated with opioids (morphine and fentanyl) commonly encountered in anaesthesia and with agents mimicking sepsis [lipopolysaccharide (LPS) and peptidoglycan G (PepG)]. Opioid receptor mRNA expression was assessed by endpoint polymerase chain reaction (PCR) with gel visualisation and quantitative PCR.

RESULTS

Classical MOP, DOP, and KOP receptors were not detected in any of the samples tested either at rest or when challenged with opioids, LPS or PepG. Commercial primers for DOP did not perform well in quantitative PCR, so the absence of expression was confirmed using a traditional gel-based approach. NOP receptors were detected in all samples; expression was unaffected by opioids and reduced by LPS/PepG combinations.

CONCLUSIONS

Classical opioid receptors are not expressed on circulating immune cells.

State-of-the-art three-dimensional analysis of soft tissue changes following Le Fort I maxillary advancement

We describe the comprehensive 3-dimensional analysis of facial changes after Le Fort I osteotomy and introduce a new tool for anthropometric analysis of the face. We studied the cone-beam computed tomograms of 33 patients taken one month before and 6-12 months after Le Fort I maxillary advancement with or without posterior vertical impaction. Use of a generic facial mesh for dense correspondence analysis of changes in the soft tissue showed a mean (SD) anteroposterior advancement of the maxilla of 5.9 (1.7) mm, and mean (SD) minimal anterior and posterior vertical maxillary impaction of 0.1 (1.7) mm and 0.6 (1.45) mm, respectively. It also showed distinctive forward and marked lateral expansion around the upper lip and nose, and pronounced upward movement of the alar curvature and columella. The nose was widened and the nostrils advanced. There was minimal forward change at the base of the nose (subnasale and alar base) but a noticeable upward movement at the nasal tip. Changes at the cheeks were minimal. Analysis showed widening of the midface and upper lip which, to our knowledge, has not been reported before. The nostrils were compressed and widened, and the lower lip shortened. Changes at the chin and lower lip were secondary to the limited maxillary impaction.

Development and characterisation of novel fentanyl-delta opioid receptor antagonist based bivalent ligands

BACKGROUND

Opioid tolerance is a limiting factor in chronic pain. Delta opioid peptide (DOP)(δ) receptor antagonism has been shown to reduce tolerance. Here, the common clinical mu opioid peptide (MOP)(µ) receptor agonist fentanyl has been linked to the DOP antagonist Dmt-Tic (2',6'-dimethyl-L-tyrosyl-1,2,3,4-tetrahydrisoquinoline-3-carboxylic acid) to create new bivalent compounds.

METHODS

Binding affinities of bivalents(#9, #10, #11, #12 and #13) were measured in Chinese hamster ovary (CHO) cells expressing recombinant human MOP, DOP, Kappa opioid peptide (KOP)(κ) and nociceptin/orphanin FQ opioid peptide (NOP) receptors. Functional studies, measuring GTPγ[(35)S] or β-arrestin recruitment, were performed in membranes or whole cells respectively expressing MOP and DOP.

RESULTS

The new bivalents bound to MOP (pKi : #9:7.31; #10:7.58; #11:7.91; #12:7.94; #13:8.03) and DOP (#9:8.03; #10:8.16; #11:8.17; #12:9.67; #13:9.71). In GTPγ[(35)S] functional assays, compounds #9(pEC50:6.74; intrinsic activity:0.05) #10(7.13;0.34) and #11(7.52;0.27) showed weak partial agonist activity at MOP. Compounds #12 and #13, with longer linkers, showed no functional activity at MOP. In antagonist assays at MOP, compounds #9 (pKb:6.87), #10(7.55) #11(7.81) #12(6.91) and #13(7.05) all reversed the effects of fentanyl. At DOP, all compounds showed antagonist affinity (#9:6.85; #10:8.06; #11:8.11; #12:9.42; #13:9.00), reversing the effects of DPDPE ([D-Pen(2,5)]enkephalin). In β-arrestin assays, compared with fentanyl (with response at maximum concentration (RMC):13.62), all compounds showed reduced ability to activate β-arrestin (#9 RMC:1.58; #10:2.72; #11:2.40; #12:1.29; #13:1.58). Compared with fentanyl, the intrinsic activity was: #9:0.12; #10:0.20; #11:0.18; #12:0.09 and #13:0.12.

CONCLUSIONS

The addition of a linker between fentanyl and Dmt-Tic did not alter the ability to bind to MOP and DOP, however a substantial loss in MOP functional activity was apparent. This highlights the difficulty in multifunctional opioid development.

Evolution of the oxygen sensitivity of cytochrome c oxidase subunit 4

Vertebrates possess two paralogs of cytochrome c oxidase (COX) subunit 4: a ubiquitous COX4-1 and a hypoxia-linked COX4-2. Mammalian COX4-2 is thought to have a role in relation to fine-tuning metabolism in low oxygen levels, conferred through both structural differences in the subunit protein structure and regulatory differences in the gene. We sought to elucidate the pervasiveness of this feature across vertebrates. The ratio of COX4-2/4-1 mRNA is generally low in mammals, but this ratio was higher in fish and reptiles, particularly turtles. The COX4-2 gene appeared unresponsive to low oxygen in nonmammalian models (zebrafish, goldfish, tilapia, anoles, and turtles) and fish cell lines. Reporter genes constructed from the amphibian and reptile homologues of the mammalian oxygen-responsive elements and hypoxia-responsive elements did not respond to low oxygen. Unlike the rodent ortholog, the promoter of goldfish COX4-2 did not respond to hypoxia or anoxia. The protein sequences of the COX4-2 peptide showed that the disulfide bridge seen in human and rodent orthologs would be precluded in other mammalian lineages and lower vertebrates, all of which lack the requisite pair of cysteines. The coordinating ligands of the ATP-binding site are largely conserved across mammals and reptiles, but in Xenopus and fish, sequence variations may disrupt the ability of the protein to bind ATP at this site. Collectively, these results suggest that many of the genetic and structural features of COX4-2 that impart responsiveness and benefits in hypoxia may be restricted to the Euarchontoglires lineage that includes primates, lagomorphs, and rodents.

[Dmt1]N/OFQ(1-13)-NH2: a potent nociceptin/orphanin FQ and opioid receptor universal agonist

BACKGROUND AND PURPOSE

Intrathecally (i.t.) administered nociceptin/orphanin FQ (N/OFQ) evokes antinociceptive effects in rodents. Recent studies in monkeys demonstrated that i.t. co-application of N/OFQ and morphine elicits synergistic antinociceptive actions suggesting mixed N/OFQ peptide (NOP) and μ opioid receptor agonists as innovative spinal analgesics. Thus, novel N/OFQ related peptides were synthesized in order to identify and pharmacologically characterize a mixed NOP/ μ opioid receptor agonist.

EXPERIMENTAL APPROACH

The following in vitro assays were used: calcium mobilization in cells expressing the human NOP or classical opioid receptors and chimeric G proteins, receptor and [(35)S]-GTPγS binding, [(35)S]-GTPγS binding in rat spinal cord membranes, guinea pig ileum bioassay. In vivo experiments were performed in monkeys using the tail withdrawal assay.

KEY RESULTS

From calcium mobilization studies [Dmt(1)]N/OFQ(1-13)-NH(2) was selected as the most potent and least selective compound. The mixed NOP/opioid full agonist activity and high affinity of [Dmt(1)]N/OFQ(1-13)-NH(2) was confirmed at human recombinant receptors in receptor binding, calcium mobilization and/or [(35)S]-GTPγS binding studies, at rat spinal cord receptors in [(35)S]-GTPγS binding experiments, and at guinea pig receptors inhibiting neurogenic contractions in the ileum. In vivo in the tail withdrawal assay in monkeys i.t. [Dmt(1) ]N/OFQ(1-13)-NH(2) was able to elicit robust and long-lasting antinociceptive effects.

CONCLUSIONS AND IMPLICATIONS

Collectively, these results demonstrate that [Dmt(1)]N/OFQ(1-13)-NH(2) behaves as NOP/opioid receptor universal agonist and substantiate the suggestion that such mixed ligands are worthy of development as innovative spinal analgesics.