Observed Trajectories of Cannabis Use and Concurrent Longitudinal Outcomes in Youth and Young Adults Receiving Coordinated Specialty Care for Early Psychosis

Cannabis use is present and persistent in young adults with early psychosis receiving Coordinated Specialty Care (CSC) in the United States. While CSC programs are effective in improving quality of life, helping individuals reach goals, and promoting recovery, cannabis use may limit the extent of these improvements. This study extended upon previous findings to examine trajectories of cannabis use among individuals with early psychosis. The sample consisted of 1325 CSC participants enrolled for more than one year at OnTrackNY and followed up to two years, categorized into three groups: no use, reduced use, and persistent use. Baseline demographic and clinical differences were compared across groups and associations between clinical and psychosocial outcomes at 12 months and 24 months were examined across groups. Of the sample, 40 % remained persistent users over two years while 12.8 % reduced their use. At baseline, persistent users were younger (p = 0.011), more likely to be male (p < 0.001), had lower education levels (p = 0.019), and were more likely to have had past legal issues prior to admission (p < 0.001) than non-users. At 2 years, persistent users had significantly worse symptom scores than non-users (p = 0.0003) and reduced users (p = 0.0004). These findings highlight the presence of persistent cannabis use being common in this population and the need to improve substance use treatment offered to allow more CSC participants to achieve improved outcomes.

Tau in cerebrospinal fluid induces neuronal hyperexcitability and alters hippocampal theta oscillations

Alzheimer's disease (AD) and other tauopathies are characterized by the aggregation of tau into soluble and insoluble forms (including tangles and neuropil threads). In humans, a fraction of both phosphorylated and non-phosphorylated N-terminal to mid-domain tau species, are secreted into cerebrospinal fluid (CSF). Some of these CSF tau species can be measured as diagnostic and prognostic biomarkers, starting from early stages of disease. While in animal models of AD pathology, soluble tau aggregates have been shown to disrupt neuronal function, it is unclear whether the tau species present in CSF will modulate neural activity. Here, we have developed and applied a novel approach to examine the electrophysiological effects of CSF from patients with a tau-positive biomarker profile. The method involves incubation of acutely-isolated wild-type mouse hippocampal brain slices with small volumes of diluted human CSF, followed by a suite of electrophysiological recording methods to evaluate their effects on neuronal function, from single cells through to the network level. Comparison of the toxicity profiles of the same CSF samples, with and without immuno-depletion for tau, has enabled a pioneering demonstration that CSF-tau potently modulates neuronal function. We demonstrate that CSF-tau mediates an increase in neuronal excitability in single cells. We then observed, at the network level, increased input-output responses and enhanced paired-pulse facilitation as well as an increase in long-term potentiation. Finally, we show that CSF-tau modifies the generation and maintenance of hippocampal theta oscillations, which have important roles in learning and memory and are known to be altered in AD patients. Together, we describe a novel method for screening human CSF-tau to understand functional effects on neuron and network activity, which could have far-reaching benefits in understanding tau pathology, thus allowing for the development of better targeted treatments for tauopathies in the future.

Consultant psychiatrists' experience of the impact of the COVID-19 pandemic on mental health services

OBJECTIVES

The novel coronavirus 2019 (COVID-19) has spread worldwide threatening human health. To reduce transmission, a 'lockdown' was introduced in Ireland between March and May 2020. The aim of this study is to capture the experiences of consultant psychiatrists during lockdown and their perception of it's impact on mental health services.

METHODS

A questionnaire designed by the Royal College of Psychiatrists was adapted and circulated to consultant members of the College of Psychiatrists of Ireland following the easing of restrictions. The questionnaire assessed the perceived impact on referral rates, mental health act provision, availability of information technology (IT), consultant well-being and availability of personal protective equipment (PPE). Thematic analysis was employed to analyse free-text sections.

RESULTS

Response rate was 32% (n = 197/623). Consultants reported an initial decrease/significant decrease in referrals in the first month of lockdown (68%, n = 95/140) followed by an increase/significant increase in the second month for both new (83%, n = 100/137) and previously attending patients (65%, n = 88/136). Social isolation and reduced face-to-face mental health supports were among the main reasons identified. The needs of children and older adults were highlighted. Most consultants (76%, n = 98/129) felt their working day was affected and their well-being reduced (52%, n = 61/119). The majority felt IT equipment availability was inadequate (67%, n = 88/132). Main themes identified from free-text sections were service management, relationship between patients and healthcare service and effects on consultants' lives.

CONCLUSIONS

The COVID-19 pandemic has placed increased pressure on service provision and consultant wellness. This further supports the longstanding need to increase mental health service investment.

440 Training in Microbiological Sampling for Toe Amputations in Diabetic Foot Disease: A Survey of UK Vascular Trainees

Aim

To determine usual practice and extent of training received by United Kingdom (UK) vascular surgery trainees in microbiological sampling for toe amputations in diabetic patients.

Method

A prospective online survey was distributed via social media networks and trainee organisations. All vascular surgery trainees in the UK were invited to participate. A total of 29 responses were included in the analysis.

Results

86% of respondents have been trained in toe amputations during registrar training. 66% have not been taught which samples to send for microbiological analysis. 10% receive regular training reviews in toe amputations. There is significant variability in the types of samples sent by trainees for microbiological analysis and the majority of trainees did not know how their samples are processed in the laboratory.

Conclusions

Toe amputations appear to be a neglected aspect of training for UK vascular surgery registrars. Lack of consistency in microbiological sampling techniques may prevent optimum antimicrobial stewardship and therefore increase the risk of further complications including major amputation. Inclusion of diabetic foot sepsis as a critical condition in the new vascular surgery curriculum may help to address this issue. A national consensus needs to be reached on how microbiological samples should be taken and processed in order for trainees to be taught in a consistent manner.

Deciphering the Agonist Binding Mechanism to the Adenosine A1 Receptor

Despite being among the most characterized G protein-coupled receptors (GPCRs), adenosine receptors (ARs) have always been a difficult target in drug design. To date, no agonist other than the natural effector and the diagnostic regadenoson has been approved for human use. Recently, the structure of the adenosine A1 receptor (A1R) was determined in the active, Gi protein complexed state; this has important repercussions for structure-based drug design. Here, we employed supervised molecular dynamics simulations and mutagenesis experiments to extend the structural knowledge of the binding of selective agonists to A1R. Our results identify new residues involved in the association and dissociation pathway, they suggest the binding mode of N6-cyclopentyladenosine (CPA) related ligands, and they highlight the dramatic effect that chemical modifications can have on the overall binding mechanism, paving the way for the rational development of a structure-kinetics relationship of A1R agonists.

Establishment of Pertussis toxin BRP batch 2 for CHO clustering assay

Recently, the Chinese hamster ovary (CHO) cell-based clustering assay replaced the in vivo Histamine Sensitisation Test (HIST) in mice in European Pharmacopoeia (Ph. Eur.) general chapter 2.6.33. ‘Residual pertussis toxin’ as the recommended method to test for residual pertussis toxin in acellular pertussis vaccine intermediates. To support the standardised CHO clustering assay, availability of a reference standard is critical. Ph. Eur. pertussis toxin Biological Reference Preparation (BRP) batch 1 was first calibrated in International Units in 2008 for the HIST and subsequently also calibrated for the CHO clustering assay in 2017. However, its stocks were dwindling and needed to be replaced. In an effort to maintain adequate supply, a project (BSP141) was initiated by the European Directorate for the Quality of Medicines & HealthCare (EDQM), under the aegis of the Biological Standardisation Programme, to establish a second pertussis toxin BRP (BRP2). Candidate material was manufactured ad hoc by an acellular pertussis vaccine manufacturer and an optimal formulation for long-term stability was defined. Exhaustive in-process and post-production controls demonstrated that the material was fit for its intended purpose and therefore a collaborative study for calibration and stability assessment of the candidate material was organised, which included 10 laboratories worldwide. As a result of the study, the candidate material was established as Ph. Eur. Pertussis toxin BRP batch 2 with a potency of 130 IU/vial for the CHO clustering assay. Unopened vials must be stored at −20°C. The BRP may be used for up to two weeks after reconstitution if appropriately handled and stored at 2–8°C.

Current level of technology use, health and eHealth literacy in older Canadians with a recent fracture-a survey in orthopedic clinics

Among older adults who have recently sustained a fracture, there is substantial adoption of mobile technology. Furthermore, health and eHealth literacy level reported by participants supports the development of interactive eHealth interventions toward fostering better patient engagement in skeletal health management.

INTRODUCTION

Electronic health resources are increasingly used in the self-management of medical conditions. We aimed to identify the current level of technology adoption, health, and eHealth literacy among older adults with a recent fracture, to determine if the use of electronic interventions would be feasible and acceptable in this population.

METHODS

Adults ≥ 50 years with recent fractures were invited to complete a self-administered survey composed of 21 questions, including an 8-item perceived eHealth literacy scale.

RESULTS

A total of 401 participants completed the survey (women, 64%; ≥ 65 years, 59%; university education, 32%). Most participants reported no difficulty in reading printed health material (67%) and felt confident in filling out medical forms (65%). Younger age and higher levels of education were associated with higher health literacy. Most respondents (81%) owned at least one mobile device (smartphone, 49%; tablet, 45%). eHEALS scores were similar among men (29, IQR 24-32) and women (29, IQR 25-33), and between younger age group categories (50-64 years, 30; IQR 26-33; and 65-74 years, 29; IQR 25-32), but lower in the oldest age group (≥ 75 years, 24; IQR 21-29; p < 0.05). Compared with the youngest group, those ≥ 75 years had higher odds of an eHEALS < 26 (odds ratio, 4.2; 95% confidence interval 2.0-8.9) after adjusting for sex and education level.

CONCLUSION

There is significant adoption of mobile technology among older adults. Health and eHealth literacy reported by this study population supports the development of interactive eHealth interventions toward fostering better patient engagement in skeletal health management.

Role of A1 receptor-activated GIRK channels in the suppression of hippocampal seizure activity

The neuromodulator adenosine is released during seizure activity to provide negative feedback suppression of ongoing activity and to delay the occurrence of the next burst of activity. Adenosine acts via multiple G-protein-coupled receptors including the A₁ receptor (A₁R) which inhibits neurotransmitter release and hyperpolarises neuronal membrane potential. The hyperpolarisation is produced, at least in part, by the activation of G-protein-activated inwardly rectifying K⁺ (GIRK) channels. We have used tertiapin-Q (TQ), a potent and selective inhibitor of GIRK channels, to assess the role of GIRK channels in controlling seizure activity in areas CA1 and CA2 of mouse hippocampal slices. TQ (100-300 nM) blocked ~50% of the adenosine-mediated membrane potential hyperpolarisation of hippocampal CA1 and CA2 neurons. TQ (100 nM) had no significant effect on synaptic transmission in area CA1 of the hippocampus but enhanced transmission in CA2, an effect prevented by blocking A₁Rs. TQ (100 nM) increased the frequency of spontaneous activity (induced by removing Mg²⁺ and increasing K⁺) and blunted the effects of exogenous adenosine on the suppression of activity. TQ had a significantly greater effect on electrically-stimulated seizure activity induced in CA2 versus that in CA1, producing a greater increase in both the duration and amplitude of the stimulated bursts. This is consistent with the greater A₁R density and A₁R activation tone in CA2. Thus GIRK channels play a role in the supressing effects of adenosine on seizure activity.

Pilot study on the use of infrared thermal imaging to predict infrainguinal bypass outcome in the immediate post-operative period

Objectives

Early bedside post-operative monitoring of infrainguinal bypass surgery is currently based on subjective clinical findings and handheld Doppler signals. Infrared thermal imaging is an objective and reproducible technique that has been proven to be a reliable and accurate method to measure skin temperature. The aim of this prospective study was to assess infrared thermal imaging as a predicting tool of bypass graft outcome in the immediate post-operative period and assess the angiosome concept.

Methods

This was a prospective cohort study of 25 patients undergoing infrainguinal bypass. Demographic and clinical data were prospectively collected and included gender, age, co-morbidities, pre- and post-operative ankle brachial pressure indices, surgery undertaken and patency of run-off vessels. Infrared thermal imaging was undertaken pre- and post-operatively to assess thermal changes to the feet following revascularisation.

Results

We found that an increase in temperature from pre- to post-operative was significantly associated with bypass patency. An increase in temperature was found to have a positive predictive value of 75%, a negative predictive value of 100%, a sensitivity of 100% and specificity of 89% for predicting graft patency.

Conclusions

Infrared thermal imaging can be used to measure temperature related changes of the microcirculation post-operatively and predict bypass outcomes in the immediate post-operative period.

"Reversible" myelodysplastic syndrome or ineffectual clonal haematopoiesis? - add(6p) myeloid neoplasm with a spontaneous cytogenetic remission

Cytotoxic chemotherapy has inherent mutagenic potential and alters the bone marrow microenvironment after therapy. In some cases, this potentiates expansion of an aberrant clone and may lead to a therapy-related myeloid neoplasm if the clone overcomes selective pressure. We present the case of a 43-year-old woman diagnosed with an indolent, therapy-related myeloid neoplasm with an isolated chromosome 6p abnormality following treatment for de novo Acute Myeloid Leukaemia (AML), who manifest a sustained spontaneous cytogenetic remission two years later, possibly due to an ineffectual or non-dominant founding clone. This case reminds us to be mindful of the possibility that clonal haematopoiesis may not always equate to clinically relevant disease, even in the setting of an abnormal clonal karyotype.

Discovery of N-arylpyrroles as agonists of GPR120 for the treatment of type II diabetes

The discovery of a novel series of N-arylpyrroles as agonists of GPR120 (FFAR4) is discussed. One lead compound is a potent GPR120 agonist, has good selectivity for related receptor GPR40 (FFAR1), has acceptable PK properties, and is active in 2 models of Type 2 Diabetes in mice.

Rapid prediction of stem cell mobilization using volume and conductivity data from automated hematology analyzers

BACKGROUND

Rapid analytics to predict circulating hematopoietic stem cells are valuable for optimal management of mobilization, particularly for the use of newer and costly mobilization agents such as plerixafor.

STUDY DESIGN AND METHODS

We used stepwise, linear multiple regression modeling applied to cell population data collected by routine hematology analyzers (Beckman Coulter DxH 800) on patients undergoing autologous stem cell collection (n = 131). Beta coefficients were used to derive a formula for a stem cell index (SCI). We then tested the correlation of SCI with stem cell counts and performance of the SCI as a predictor of poor mobilization with external validation in a separate cohort (n = 183).

RESULTS

The SCI correlated strongly with CD34 counts by flow cytometry (r = 0.8372 in the development cohort, r = 0.8332 in the external validation cohort) and compares favorably with other rapid stem cell enumerating technologies. In the external validation cohort, the SCI performed well as a predictor (receiver operating characteristic area under the curve, 0.9336) of poor mobilization (CD34 count < 10), with a sensitivity of 72% and a specificity of 93%. When prevalence of poor mobilization was 33%, this resulted in a positive predictive value of 83% and a negative predictive value of 87%. The SCI also showed promise in tracking responses to plerixafor administration.

CONCLUSION

The findings demonstrate the utility of the cell population data collected by hematology analyzers to provide rapid data beyond standard complete blood counts, particularly for stem cell count prediction, requiring no additional reagents, specimen, or instrumentation.

Atypical femur fractures: a survey of current practices in orthopedic surgery

The results of a self-administered online survey demonstrate that orthopedic surgeons' management practices for AFF are variable. These data will inform the development of clinical practice guidelines.

INTRODUCTION

We aimed to determine current AFF treatment practices of orthopedic surgeons to inform clinical practice guideline development.

METHODS

A self-administered online survey was developed and sequentially posted on the Orthopaedic Trauma Association (OTA) website from July to August 2015 and the Canadian Orthopaedic Association (COA) website from December 2015 to January 2016. Level of confidence in diagnosis and treatment as well as treatment preferences between respondents who self-identified as trauma surgeons vs. non-trauma surgeons were compared.

RESULTS

A total of 172 completed surveys were obtained (OTA, N = 100, 58%; COA, N = 72, 8%). Seventy-eight percent of respondents had treated ≥1 AFF in the previous 6 months. Seventy-six percent reported feeling extremely or very confident in diagnosing AFF (trauma 84% vs. non-trauma surgeons 70%, p = 0.04), and 63% reported feeling extremely or very confident in treating AFF (trauma 82%, non-trauma surgeons 50%, p < 0.01). Preferred management for complete and symptomatic incomplete AFFs was surgical fixation with a cephalomedullary nail (CMN) by 88 and 79%, respectively, while close follow-up was preferred for asymptomatic incomplete AFFs in 72% of respondents. Trauma surgeons used the CMN more frequently than non-trauma surgeons (90 vs. 76% p = 0.03). In patients with bilateral AFFs, with one side surgically treated, 56% were extremely likely to surgically treat the contralateral side, if symptomatic. Most felt guidelines (81%) and educational resources (73%) would be valuable.

CONCLUSIONS

Current orthopedic treatment practices for AFFs are variable. The results of this survey will inform the development of practice guidelines and educational resources.

Safety and Efficacy of Isolated Limb Infusion Chemotherapy for Advanced Locoregional Melanoma in Elderly Patients: An Australian Multicenter Study

BACKGROUND

Isolated limb infusion (ILI) offers a minimally invasive treatment option for locally advanced extremity melanoma.

OBJECTIVE

The aim of the current study was to evaluate the safety and efficacy of ILI in elderly patients in an Australian multicenter setting.

METHODS

The results of 316 first ILI procedures, performed between 1992 and 2008 in five Australian institutions, were identified and analyzed, with the main focus on elderly patients (≥75 years of age). All institutions used the same protocol: melphalan was circulated in the isolated limb for 20-30 min (±actinomycin D), and toxicity, responses, and survival were recorded.

RESULTS

Characteristics of patients aged ≥75 years (n = 148) were similar to those aged <75 years (n = 168), except that older patients had more melanoma deposits (median 4 vs. 5; p = 0.035) and lower limb volumes (5.4 vs. 6.5 L; p = 0.001). Median drug circulation times were lower in the older group (21 vs. 24 min; p = 0.04), and older patients experienced less limb toxicity (grade III/IV in 22 and 37% of patients, respectively; p = 0.003). A complete response (CR) was seen in 27% of patients aged ≥75 years and in 38% of patients aged <75 years (p = 0.06), while overall response rates were 72 and 77%, respectively (p = 0.30). No difference in survival was seen (p = 0.69).

CONCLUSIONS

The ILI technique proved safe and effective in elderly patients. When present, toxicity was localized, and lower compared with younger patients, possibly due to shorter drug circulation times. CR rates were higher in younger patients, although not significantly, while overall response and survival were equal. Optimization of perioperative factors in elderly patients may allow response rates to be raised further, while maintaining low toxicity.

Discovery of Orally Efficacious Tetrahydrobenzimidazoles as TGR5 Agonists for Type 2 Diabetes

We have discovered a novel series of tetrahydrobenzimidazoles 3 as TGR5 agonists. Initial structure-activity relationship studies with an assay that measured cAMP levels in murine enteroendocrine cells (STC-1 cells) led to the discovery of potent agonists with submicromolar EC₅₀ values for mTGR5. Subsequent optimization through methylation of the 7-position of the core tetrahydrobenzimidazole ring resulted in the identification of potent agonists for both mTGR5 and hTGR5 (human enteroendocrine NCI-H716 cells). While the lead compounds displayed low to moderate exposure after oral dosing, they significantly reduced blood glucose levels in C57 BL/6 mice at 30 mg/kg and induced a 13-22% reduction in the area under the blood glucose curve (AUC)_0-120 min in oral glucose tolerance tests (OGTT).

Role of vitamin A metabolism in IIH: Results from the idiopathic intracranial hypertension treatment trial

INTRODUCTION

Vitamin A and its metabolites (called retinoids) have been thought to play a role in the development of idiopathic intracranial hypertension (IIH). The IIH Treatment Trial (IIHTT) showed the efficacy of acetazolamide (ACZ) in improving visual field function, papilledema grade, quality of life and cerebrospinal fluid (CSF) pressure. We postulated that IIH patients would demonstrate elevated measures of vitamin A metabolites in the serum and CSF.

METHODS

Comprehensive measures of serum vitamin A and its metabolites were obtained from 96 IIHTT subjects, randomly assigned to treatment with ACZ or placebo, and 25 controls with similar gender, age and body mass index (BMI). These included retinol, retinol binding protein, all-trans retinoic acid (ATRA), alpha- and beta-carotenes, and beta-cryptoxanthin. The IIHTT subjects also had CSF and serum vitamin A and metabolite measurements obtained at study entry and at six months.

RESULTS

At study entry, of the vitamin A metabolites only serum ATRA was significantly different in IIHTT subjects (median 4.33nM) and controls (median 5.04nM, p=0.02). The BMI of IIHTT subjects showed mild significant negative correlations with serum ATRA, alpha- and beta-carotene, and beta-cryptoxanthin. In contrast, the control subject BMI correlated only with serum ATRA. At six months, the serum retinol, alpha-carotene, beta-carotene, and CSF retinol were increased from baseline in the ACZ treated group, but only increases in alpha-carotene (p=0.02) and CSF ATRA (p=0.04) were significantly greater in the ACZ group compared with the placebo group. No other vitamin A measures were significantly altered over the six months in either treatment group. Weight loss correlated with only with the change in serum beta-carotene (r=-0.44, p=0.006) and the change in CSF retinol (r=-0.61, p=0.02).

CONCLUSION

Vitamin A toxicity is unlikely a contributory factor in the causation of IIH. Our findings differ from those of prior reports in part because of our use of more accurate quantitative methods and measuring vitamin A metabolites in both serum and CSF. ACZ may alter retinoid metabolism in IIH patients.

The clinical utility of genetic testing of tissues from pregnancy losses

OBJECTIVE

To map the current testing being undertaken following pregnancy loss across the UK and to examine the clinical utility in terms of identifying a cause for the loss and in identifying couples at risk of an unbalanced liveborn child.

DESIGN

Retrospective audit.

SETTING

UK, for the year 2014.

POPULATION

An audit of 6465 referrals for genetic testing of tissue samples following pregnancy loss.

METHODS

Data were obtained by questionnaire from 15 UK regional genetics laboratories.

MAIN OUTCOME MEASURES

Data were analysed with respect to gestational age, the presence of identified fetal anomalies, methodologies used, abnormality rates and the presence of a parental balanced rearrangement.

RESULTS

Of 6465 referrals a genetic cause was identified in 22% of cases (before 12 weeks' gestation, in 47%; at 12-24 weeks, in 14%; after 24 weeks, in 6%). In 0.4% of cases a balanced parental rearrangement was identified where there was a risk of an affected liveborn child in a future pregnancy. Eighty percent of genetic imbalances identified were aneuploidy or triploidy and could be identified by quantitative fluorescence polymerase chain reaction alone. There was significant variation across the UK in acceptance criteria, testing strategies and thus level of resolution of testing.

CONCLUSIONS

Genetic testing of tissues following pregnancy loss identifies a probable cause of fetal demise in 22% of cases, but it is of low clinical utility in identifying couples at risk of a future unbalanced liveborn child. A comprehensive multidisciplinary review is needed to develop proposals for an affordable and equitable service.

TWEETABLE ABSTRACT

UK audit of genetic testing of fetal loss shows variation in access to and resolution of analysis.

Large-amplitude internal waves benefit corals during thermal stress

Tropical scleractinian corals are particularly vulnerable to global warming as elevated sea surface temperatures (SSTs) disrupt the delicate balance between the coral host and their algal endosymbionts, leading to symbiont expulsion, mass bleaching and mortality. While satellite sensing of SST has proved a reliable predictor of coral bleaching at the regional scale, there are large deviations in bleaching severity and mortality on the local scale that are poorly understood. Here, we show that internal waves play a major role in explaining local coral bleaching and mortality patterns in the Andaman Sea. Despite a severe region-wide SST anomaly in May 2010, frequent upslope intrusions of cold sub-pycnocline waters due to breaking large-amplitude internal waves (LAIW) mitigated coral bleaching and mortality in shallow waters. In LAIW-sheltered waters, by contrast, bleaching-susceptible species suffered severe bleaching and total mortality. These findings suggest that LAIW benefit coral reefs during thermal stress and provide local refugia for bleaching-susceptible corals. LAIW are ubiquitous in tropical stratified waters and their swash zones may thus be important conservation areas for the maintenance of coral diversity in a warming climate. Taking LAIW into account can significantly improve coral bleaching predictions and provide a valuable tool for coral reef conservation and management.

Discovery and SAR of a novel series of 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles as N-type calcium channel inhibitors

A novel series of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles were investigated as N-type calcium channel blockers (Cav2.2 channels), a chronic pain target. One compound was active in vivo in the rat CFA pain model.

Australian multi-center experience outside of the Sydney Melanoma Unit of isolated limb infusion chemotherapy for melanoma

INTRODUCTION

Isolated limb infusion (ILI) is a minimally invasive alternative to isolated limb perfusion (ILP) for delivering high-dose regional chemotherapy to treat locally advanced limb melanoma. The current study aimed to evaluate the applicability of ILI in four Australian tertiary referral centers outside of its originating institution, the Sydney Melanoma Unit (SMU; currently known as the Melanoma Institute Australia).

METHODS

Data of 131 patients, treated between 1992 and 2008 were collectively analyzed. The ILI procedures were based on the Sydney Melanoma Unit protocol using melphalan. Response was determined using the WHO criteria and toxicity was assessed using the Wieberdink scale.

RESULTS

The median patient age was 74 years (range 28-100). Fifty-six percent were female. Overall response (OR) rate to ILI was 63% (CR 27%; PR 36%). Wieberdink toxicity grade III or higher was seen in 13%. No toxicity-related amputations occurred. Median follow-up was 24 months; median survival was 58 months. In patients with a complete response (CR), median survival was 101 months; in patients with a partial response (PR) this was 41 months (P = 0.026). On univariate analysis a younger age, lower-limb procedures and a lower Breslow thickness of the primary melanoma were associated with a favorable response. On multivariate analysis Breslow thickness and lower-limb ILI remained significant predictors for response.

CONCLUSION

In this, to date, largest multi-center study of ILI for melanoma the results are comparable to other reports and demonstrate that ILI can be widely implemented and safely applied across tertiary referral centers.

Transport of very preterm infants with respiratory distress syndrome using nasal continuous positive airway pressure

AIM

To audit clinical practice during transport of very preterm infants (<32 weeks) with acute respiratory distress syndrome (RDS) receiving nasal continuous positive airway pressure (NCPAP).

METHODS

Retrospective cohort study.

RESULTS

Twenty-seven infants were receiving NCPAP before transport team's arrival, and 23 were commenced on NCPAP after team's arrival. Six infants (12%) failed NCPAP before transfer, 2 infants (4.5%) failed NCPAP less than 24 hours, and 5 infants (11.3%) failed more than 24 hours - 7 days following admission. None died or developed pneumothorax during, or 7 days after admission. We did not observe NCPAP failure during transfer. There was a statistically significant difference between the NCPAP success and NCPAP failure groups for FiO2 at admission (p < 0.05), and the duration of NCPAP (p < 0.05).

CONCLUSION

NCPAP is a potentially safe and effective mode of respiratory support for very preterm infants during ground, and air transports.

Imperfect informed consent for prenatal screening: Lessons from the Quad screen

Objective

The study evaluated patient informed consent (IC) for the Quad screen and examined differences in IC between test acceptors and test refusers. A multidimensional model of IC was used.

Methods

Women seeking prenatal care at nine obstetrics clinics in a large Midwestern city completed surveys between February and December 2006. Surveys contained measures for three dimensions of IC: intention, understanding and controlling influence.

Results

56.2% of women did not meet criteria for all three of our dimensions of IC and therefore failed to give it. The failure rate was higher among women who choose to screen (72.6%) than women who choose not screen (50%) (p < 0.001). Women who met all criteria for IC were over three times less likley to choose to screen (or = 0.32, CI 0.17–0.62 ( p < 0.01)) than women who did not meet criteria for IC.

Conclusion

The decision to screen for fetal anomalies is less of a deliberated action than the decision not to screen. Women who lack a fundamental understanding of the purpose and nature of the screen may be operating on the belief that the screen is part of standard care and presents no need to deliberate.

A GIS-based methodology for selecting stormwater disconnection opportunities

The purpose of this paper is to introduce a geographic information system (GIS)-based decision support tool that assists the user to select not only areas where (retrofit) sustainable drainage systems (SuDS) could be implemented within a large catchment (>100 ha), but also to allow discrimination between suitable SuDS techniques based on their likely feasibility and effectiveness. The tool is applied to a case study catchment within London, UK, with the aim of increasing receiving water quality by reducing combined sewer overflow (CSO) spill frequency and volume. The key benefit of the tool presented is to allow rapid assessment of the retrofit SuDS potential of large catchments. It is not intended to replace detailed site investigations, but may help to direct attention to sites that have the greatest potential for retrofit SuDS implementation. Preliminary InfoWorks CS modelling of 'global disconnections' within the case study catchment, e.g. the removal of 50% of the total impervious area, showed that CSO spill volume could be reduced by 55 to 78% during a typical year. Using the disconnection hierarchy developed by the authors, the feasibility of retrofit SuDS deployment within the case study catchment is assessed, and the implications discussed.

Activity-dependent release of adenosine: a critical re-evaluation of mechanism

Adenosine is perhaps the most important and universal modulator in the brain. The current consensus is that it is primarily produced in the extracellular space from the breakdown of previously released ATP. It is also accepted that it can be released directly, as adenosine, during pathological events primarily by equilibrative transport. Nevertheless, there is a growing realization that adenosine can be rapidly released from the nervous system in a manner that is dependent upon the activity of neurons. We consider three competing classes of mechanism that could explain neuronal activity dependent adenosine release (exocytosis of ATP followed by extracellular conversion to adenosine; exocytotic release of an unspecified transmitter followed by direct non-exocytotic adenosine release from an interposed cell; and direct exocytotic release of adenosine) and outline discriminatory experimental tests to decide between them. We review several examples of activity dependent adenosine release and explore their underlying mechanisms where these are known. We discuss the limits of current experimental techniques in definitively discriminating between the competing models of release, and identify key areas where technologies need to advance to enable definitive discriminatory tests. Nevertheless, within the current limits, we conclude that there is evidence for a mechanism that strongly resembles direct exocytosis of adenosine underlying at least some examples of neuronal activity dependent adenosine release.

Biosensor measurement of purine release from cerebellar cultures and slices

We have previously described an action-potential and Ca²⁺-dependent form of adenosine release in the molecular layer of cerebellar slices. The most likely source of the adenosine is the parallel fibres, the axons of granule cells. Using microelectrode biosensors, we have therefore investigated whether cultured granule cells (from postnatal day 7–8 rats) can release adenosine. Although no purine release could be detected in response to focal electrical stimulation, purine (adenosine, inosine or hypoxanthine) release occurred in response to an increase in extracellular K⁺ concentration from 3 to 25 mM coupled with addition of 1 mM glutamate. The mechanism of purine release was transport from the cytoplasm via an ENT transporter. This process did not require action-potential firing but was Ca²⁺dependent. The major purine released was not adenosine, but was either inosine or hypoxanthine. In order for inosine/hypoxanthine release to occur, cultures had to contain both granule cells and glial cells; neither cellular component was sufficient alone. Using the same stimulus in cerebellar slices (postnatal day 7–25), it was possible to release purines. The release however was not blocked by ENT blockers and there was a shift in the Ca²⁺ dependence during development. This data from cultures and slices further illustrates the complexities of purine release, which is dependent on cellular composition and developmental stage.

Distal revascularisation with interval ligation (DRIL): an experience

INTRODUCTION

The global increase of chronic renal failure has resulted in a growing number of patients on haemodialysis using arteriovenous fistulas (AVFs). By virtue of their very function, AVFs at times shunt blood away from regions distally, resulting in an ischaemic steal syndrome. Distal revascularisation with interval ligation (DRIL) has been described as a procedure to treat symptomatic ischaemic steal. We present our experience in the management of this complication.

PATIENTS AND METHODS

Six patients with severe ischaemic steal were treated using a DRIL procedure between May 2004 and June 2007. There were three males and three females, all with elbow brachiocephalic AVFs. Symptoms ranged from severe rest pain to digital gangrene. Published results from international studies of 135 DRIL procedures were also reviewed.

RESULTS

Vascular access was maintained along with the elimination of ischaemic symptoms in the six patients using an ipsilateral reversed basilic vein graft. Interval ligation of the distal brachial artery was performed at the same time. All patients showed immediate and sustained clinical improvement of symptoms with a demonstrable increase in digital pulse oximetry.

CONCLUSIONS

DRIL is a beneficial treatment option that has proven successful at alleviating ischemic steal symptoms and preserving vascular access. This avoids placement of central lines, its associated risks, and the need to create an alternative sited fistula.