Celebrating Australian nurses who are pioneering the response to climate change: a compilation of case studies

BACKGROUND

Nurses, the largest healthcare workforce, are well placed to provide leadership in initiatives that promote planetary health. Yet, few practical examples of nurse leadership in the health sector's response to climate change are evident in the scholarly literature.

AIM

The aim of this discussion paper is to profile Australian nurses who are leading initiatives designed to champion planetary health and promote sustainable practice.

METHODS

The paper presents a series of case studies derived from interviews conducted in October and November 2023.

FINDINGS

The nurses' experiences and insights, along with the challenges they have encountered, are presented as evidence of Kouzes and Posner's five practices of exemplary leadership.

CONCLUSION

The case studies demonstrate that appointment of more nurses with climate and sustainability expertise will accelerate the implementation of responsive strategies that target waste management, emissions reduction and climate resilience across healthcare organisations.

In praise of postgraduate career clinics: Translating health professionals' willingness to engagement

AIM

To capture and retain healthcare staff in postgraduate courses relevant to individual career aspirations, service requirements and continuous practice development (CPD) within an English UK university.

DESIGN

Two virtual career clinics for postgraduate practitioners to engage in CPD offers within the university. An online post-enrolment online survey to explore their experiences of engagement with the university.

METHODS

Mixed: qualitative and quantitative methods. Engaging 10 participants attended the career clinics, and 42 participants with an online survey.

RESULTS

The career clinics were well received by participants who mapped CPD requirements and individual career aspirations. The surveys exposed challenges with marketing and enrolment; however, these were mitigated with support. Four recommendations are presented within this paper applicable to the international postgraduate education of all health practitioners.

Elevated plasma matrix metalloproteinases associate with Mycobacterium tuberculosis blood stream infection and mortality in HIV-associated tuberculosis

Mortality from HIV-associated tuberculosis (HIV-TB) is high, particularly among hospitalised patients. In 433 people living with HIV admitted to hospital with symptoms of TB, we investigated plasma matrix metalloproteinases (MMP) and matrix-derived biomarkers in relation to TB diagnosis, mortality and Mycobacterium tuberculosis (Mtb) blood stream infection (BSI). Compared to other diagnoses, MMP-8 was elevated in confirmed TB and in Mtb-BSI, positively correlating with extracellular matrix breakdown products. Baseline MMP-3, -7, -8, -10 and procollagen III N-terminal propeptide (PIIINP) associated with Mtb-BSI and 12-week mortality. These findings implicate MMP dysregulation in pathophysiology of advanced HIV-TB and support MMP inhibition as a host-directed therapeutic strategy for HIV-TB.

Advancing beyond the Hippocampus to Preserve Cognition for Patients with Brain Metastases: Dosimetric Results from a Phase 2 Trial of Memory-Avoidance Whole Brain Radiotherapy

PURPOSE/OBJECTIVE(S)

Recent advances to preserve neurocognitive function in patients treated for brain metastases include stereotactic radiosurgery (SRS), hippocampal avoidance whole brain radiation therapy (HA-WBRT), and memantine administration. However, 23% of patients receiving HA-WBRT and memantine on NRG-CC001 still experienced executive function deterioration at 4 months, with 12% experiencing total recall and delayed recognition deterioration at 6 months. The hippocampus, corpus callosum, fornix, and amygdala are key neurocognitive substructures with a low propensity for brain metastases. Herein, we report our preliminary experience using an advanced "memory-avoidance" WBRT (MA-WBRT) approach sparing these substructures for patients with multiple (>15) brain metastases.

MATERIALS/METHODS

Ten consecutive patients treated with MA-WBRT on a phase 2 clinical trial (OSU-21074) were reviewed. In each patient, the hippocampi, amygdalae, corpus callosa, and fornix were contoured. Patients were not eligible for MA-WBRT if they had metastases in these substructures. A memory- avoidance region created using a 5mm volumetric expansion around these substructures. Hotspots were avoided in the hypothalamus and pituitary gland. Dose constraints for these avoidance structures were modeled after NRG CC-001 and include a D100% ≤ 9 Gy and a D0.03 cc ≤ 16 (acceptable to 20 Gy). Coverage of brain metastases was prioritized over memory avoidance dose constraints. Linac-based volumetric modulated arc therapy (VMAT) plans were generated for a prescription dose of 30 Gy in 10 fractions.

RESULTS

On average, the memory avoidance structure volume was 37.1 ccs (Range: 25.2-44.6 ccs), occupying 2.5% of the entire whole brain target volume. All treatment plans met the D100% dose constraint, and 8/10 plans met the D0.03cc constraint, with priority given to tumor coverage for the remaining 2 cases. VMAT spared the memory avoidance structures with a median dose range of 10.8-14.2 Gy and a maximum dose (D0.03cc) range of 15.6-22.7 Gy. The mean dose to the memory avoidance structures was 12.7 Gy (Range: 11.5-13.8 Gy). Target coverage (D98% > 25 Gy) and homogeneity (D2% ≤ 37.5 Gy) were achieved for all plans.

CONCLUSION

Modern VMAT techniques allow for sparing of the hippocampus, amygdala, corpus callosum, and fornix with good target coverage and homogeneity. Prospective quality of life and cognitive data including are being collected and include the Functional Assessment of Cancer Therapy - Brain (Fact-Br), Hopkins Verbal Learning Test (HLVT-R), Trail Making Test A/B (TMT-A/B) and Controlled Oral Word Association Test (COWAT). After enrollment is completed, these data will be evaluated to assess the efficacy of MA-WBRT to mitigate declines in quality of life and cognition after whole brain radiation.

Higher Temperatures in Socially Vulnerable US Communities Increasingly Limit Safe Use of Electric Fans for Cooling

As the globe warms, people will increasingly need affordable, safe methods to stay cool and minimize the worst health impacts of heat exposure. One of the cheapest cooling methods is electric fans. Recent research has recommended ambient air temperature thresholds for safe fan use in adults. Here we use hourly weather reanalysis data (1950-2021) to examine the temporal and spatial evolution of ambient climate conditions in the continental United States (CONUS) considered safe for fan use, focusing on high social vulnerability index (SVI) regions. We find that although most hours in the day are safe for fan use, there are regions that experience hundreds to thousands of hours per year that are too hot for safe fan use. Over the last several decades, the number of hours considered unsafe for fan use has increased across most of the CONUS (on average by ∼70%), with hotspots across the US West and South, suggesting that many individuals will increasingly need alternative cooling strategies. People living in high-SVI locations are 1.5-2 times more likely to experience hotter climate conditions than the overall US population. High-SVI locations also experience higher rates of warming that are approaching and exceeding important safety thresholds that relate to climate adaptation. These results highlight the need to direct additional resources to these communities for heat adaptive strategies.

Complications of oxidised regenerated cellulose at Caesarean section: A report of two cases

Two patients underwent surgical deliveries within four months of one another at a single maternity unit. Both patients had complications of infection-like symptoms such as offensive vaginal discharge and pyrexia, months following their caesarean sections resulting in further surgery. The incidents were thought to be secondary to woven oxidised regenerated cellulose (ORC) use. ORC must be used according to its relevant product literature which can vary between brands. Surgeons must keep abreast of changes to the haemostatic material provided to them and therefore the properties of each type, especially when faced with bleeding not suitable for suturing or electrocautery.

Educating the educators: Implementing cultural safety in the nursing and midwifery curriculum

BACKGROUND

The Australian Nursing and Midwifery Accreditation Council mandates the teaching of cultural safety in Bachelor of Nursing and Midwifery programs in Australia. However nursing and midwifery academics may lack the awareness and knowledge required to share and develop cultural safety practices with their students. Specific cultural safety professional development for academics may be needed.

OBJECTIVES

This research explores how nursing and midwifery academics at an Australian university understand cultural safety and whether they are equipped to embed it in the curriculum. It also examines whether professional development workshops can support academics to prepare for cultural safety.

METHODS

An intervention involving three cultural safety professional development workshops was offered to nursing academics at an Australian university. The authors used qualitative surveys to consider whether the workshops deepened participants' understanding of cultural safety and developed the self-reflection required to embed cultural safety in teaching.

RESULTS

The workshops contributed to participants' improved understandings of culture, colonisation, white privilege and the need for self-reflection, but not all participants developed a working knowledge of cultural safety practice.

CONCLUSION

Professional development workshops can assist nursing and midwifery academics to develop their knowledge of cultural safety, but detailed, contextual understanding is likely to need more than three sessions. Academics' motivations to include cultural safety in their teaching may be linked to their desire for patient-driven and equitable services and a desire to meet accreditation requirements.

On the adsorption and reactivity of element 114, flerovium

Flerovium (Fl, element 114) is the heaviest element chemically studied so far. To date, its interaction with gold was investigated in two gas-solid chromatography experiments, which reported two different types of interaction, however, each based on the level of a few registered atoms only. Whereas noble-gas-like properties were suggested from the first experiment, the second one pointed at a volatile-metal-like character. Here, we present further experimental data on adsorption studies of Fl on silicon oxide and gold surfaces, accounting for the inhomogeneous nature of the surface, as it was used in the experiment and analyzed as part of the reported studies. We confirm that Fl is highly volatile and the least reactive member of group 14. Our experimental observations suggest that Fl exhibits lower reactivity towards Au than the volatile metal Hg, but higher reactivity than the noble gas Rn.

First Study on Nihonium (Nh, Element 113) Chemistry at TASCA

Nihonium (Nh, element 113) and flerovium (Fl, element 114) are the first superheavy elements in which the 7p shell is occupied. High volatility and inertness were predicted for Fl due to the strong relativistic stabilization of the closed 7p 1/2 sub-shell, which originates from a large spin-orbit splitting between the 7p 1/2 and 7p 3/2 orbitals. One unpaired electron in the outermost 7p 1/2 sub-shell in Nh is expected to give rise to a higher chemical reactivity. Theoretical predictions of Nh reactivity are discussed, along with results of the first experimental attempts to study Nh chemistry in the gas phase. The experimental observations verify a higher chemical reactivity of Nh atoms compared to its neighbor Fl and call for the development of advanced setups. First tests of a newly developed detection device miniCOMPACT with highly reactive Fr isotopes assure that effective chemical studies of Nh are within reach.

1065 Exposing the Incidence of Ileus in Pelvic and Acetabular Fractures: A Retrospective Case Analysis

Background

Paralytic ileus is a temporary inhibition of gastrointestinal mobility in the absence of mechanical obstruction. Ileus has previously been observed in up to 40% of patients undergoing bowel surgery, leading to increased morbidity and length of stay. Pelvic and acetabular fractures are often caused by high energy trauma and are associated with a risk of visceral injury. This is the first study to report the incidence of and risk factors for ileus following admission with pelvic and/or acetabular fractures.

Method

All patients over the age of 16 presenting to a major trauma centre throughout 2019 were included. Data included patient demographics, injury pattern, fracture management and presence of ileus. Previous studies identified patients as having ileus if they failed to tolerate an oral diet and open their bowels for more than three days (GI-2). Analysis assessed risk factors for ileus as well as its effect on length of stay.

Results

An incidence of ileus of 40.35% was observed in the 57 included patients. Ileus was three times more common in patients with a diagnosis of diabetes mellitus (p = 0.56) and 2.5 times more common in the presence of an open pelvic/acetabular fracture (p = 0.73). Length of stay was significantly longer in patients under 65 years identified as having ileus (p = 0.046). Gender, age, opiate use, fracture management and surgical approach were not identified as risk factors.

Conclusions

The authors have identified the essentiality of early risk factor identification and hope to encourage further research to create a prognostic tool.

965 Complication Rates in Operatively Managed Ankle Fracture/Dislocations - The Effect of Pre-Reduction Imaging and Compliance with BOAST 12 Guidance

Aim

The BOAST-12 guidelines for the management of ankle fractures aims to optimise functional recovery and reduce complications. They advise against having radiographs prior to urgent reduction of clinically deformed ankles as it could cause an unacceptable delay to subsequent management. Our study aimed to assess the effect of time to acceptable reduction on the risk of complications and time to definitive reduction.

Method

This was a retrospective observational study of patients with ankle fracture-dislocations between 2013 to 2017 at the Northern General Hospital’s Emergency Department (ED). Information collected from 2 patient groups (with and without pre-reduction radiographs), included patient demographics, time to accepted reduction, number of manipulations, operations, and subsequent complications.

Results

242 patients were identified. Time from arrival in ED to acceptable reduction was significantly longer in patients with pre-reduction radiographs versus patients without (184.5 vs 82 minutes, p < 0.00), but did not increase the overall risk of complications (p = 0.62). Pre-reduction radiographs were associated with insignificantly higher rates of post-traumatic osteoarthritis (p = 0.17) and slightly longer wait time for definitive intervention (1 vs 2 days, p = 0.72). However, this had no relationship with the number of manipulations (p = 0.53).

Conclusions

The use of pre-reduction radiographs significantly increased time to acceptable reduction of ankle fracture-dislocations. However, this was not associated with increased risk of complications or time to definitive management.

1005 Antibiotic-Impregnated Calcium Sulfate Beads Are Not Effective in the Primary Prevention of Infection in Open Femur and Tibia Fractures

Introduction

Infection is a major complication of open fractures. Antibiotic-impregnated calcium sulfate (AICS) beads are widely used as an adjuvant to systemic antibiotics. Whilst their efficacy in the secondary prevention of infection is established, we present the first retrospective study evaluating AICS beads in the primary prevention of infection in open fractures.

Method

214 open femur and tibia fractures in 207 patients were reviewed over a seven-year period. 148 fractures received only systemic antibiotic prophylaxis. 66 fractures also received AICS beads. The occurrence of acute infection (wound infection and acute osteomyelitis) was recorded, as well as that of long-term complications (chronic osteomyelitis, non-union and death).

Results

Fractures that received AICS with systemic antibiotics had an overall acute infection rate of 42% (28/66), compared to 43% (63/148) in fractures that received only systemic antibiotics (p > 0.05). There was no significant difference in infection rate even when fractures were stratified by Gustilo-Anderson grade. There was also no significant difference in the rate of long-term complications.

Conclusions

Our results indicate that the adjuvant use of AICS beads is not effective for the primary prevention of acute infection or long-term complications in open leg fractures. Further research is needed to elucidate the factors influencing the outcomes of AICS use.

AB1332-HPR ASSESSING THE PATIENT EXPERIENCE OF LUPUS NEPHRITIS: DEVELOPMENT OF A CONCEPTUAL MODEL AND REVIEW OF EXISTING PATIENT-REPORTED OUTCOME (PRO) MEASURES

Background:

Lupus nephritis (LN) is an autoimmune disease characterized by inflammation of the kidneys as a result of systemic lupus erythematosus (SLE). Approximately 50% of SLE patients will develop LN, which is considered to be one of the most severe manifestations of SLE and the leading cause of morbidity and mortality in SLE. While there is ample existing evidence on disease experience and PROs used in extra-renal SLE, little research has been done in LN. Qualitative interviews with patients can help identify concepts that are both important and relevant to the patient. In order to effectively evaluate treatment benefit, it is critical that PRO measures used to assess such concepts and define clinical trial endpoints are fit for purpose and have strong evidence of content validity in the specific context of use.

Objectives:

The objective of this study was to understand the patient experience of LN and to identify and characterize the signs and symptoms of LN and their impact on health-related quality of life (HRQoL) through the development of a disease-specific conceptual model. This model was then used to evaluate the content validity of existing PRO measures available for use in LN.

Methods:

A structured literature search was conducted in Medline, Embase and PsycINFO to identify qualitative research articles documenting the patient experience of LN. PRO measures developed or commonly used to assess patient experiences of LN were also identified. Semi-structured concept elicitation interviews were conducted with 15 adult patients in the US with a clinician-confirmed diagnosis of LN (defined in accordance with established clinical guidelines). Supplementary qualitative data were also collected from a review of publicly available online blogs/forums. Findings were used to inform the development of a conceptual model detailing the impact of LN signs, symptoms and HRQoL and evaluate the validity of existing measures used within LN.

Results:

Searches revealed a paucity of qualitative research conducted with LN patients, supporting the need for prospective research in LN. Consistent with existing literature in SLE, the core signs and symptoms identified from the qualitative literature review, interviews and blog/forum review included joint pain, fatigue, joint stiffness, swelling (particularly in the extremities) and skin rashes. LN patients also reported urinary frequency, urgency, foamy urine and blood in their urine. Disease impact on physical functioning, activities of daily living, emotions, social life, work/finances and sleep were reported. PRO measures commonly used to evaluate patient experiences in LN included the SF-36, LupusQOL, LupusPRO, SLE Symptom Checklist, KDQoL and KSQ. Conceptual mapping of instruments against the newly developed conceptual model (Figure 1) highlighted that no single measure provides a comprehensive assessment of all symptoms/impact important to LN patients. Furthermore, items are largely focused on impact of symptoms with few items on symptom severity.

Figure 1.

Conceptual model of lupus nephritis symptoms and associated impacts

Conclusion:

The presentation of signs and symptoms in LN patients appears similar to those reported in extra-renal SLE populations, with the addition of swelling and urinary symptoms. Qualitative research with LN patients guided the development of a comprehensive LN conceptual model outlining the disease experience from the patients’ perspective. These insights can be useful to inform PRO measurement strategies for clinical trials in LN.

Acknowledgments:

With thanks to Dr. Betty Diamond and Dr. David Wofsy for their collaboration and helpful insights

Disclosure of Interests:

Pamela Berry Employee of: Janssen, Kate Burrows Consultant of: Adelphi Values a health outcomes research company commissioned by Janssen to conduct the research reported in this abstract, Rebecca Hall Consultant of: Adelphi Values a health outcomes research company commissioned by Janssen to conduct the research reported in this abstract., Adam Gater Consultant of: Adelphi Values a health outcomes research company commissioned by Janssen to conduct the research reported in this abstract, Helena Bradley Consultant of: Adelphi Values a health outcomes research company commissioned by Janssen to conduct the research reported in this abstract, Amy Ward Consultant of: Adelphi Values a health outcomes research company commissioned by Janssen to conduct the research reported in this abstract, Chloe Tolley Consultant of: Adelphi Values a health outcomes research company commissioned by Janssen to conduct the research reported in this abstract, Patricia Delong Employee of: Janssen, Elizabeth C Hsia Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC

Predicting Early Stages of Beef Respiratory Disease Using Thermal Imaging Technology

ObjectivesThe objective of this research was to utilize thermal imaging technology to estimate body temperature, so that an early stage of BRD can be detected.Materials and MethodsNinety-two steers were restrained in a squeeze chute that is housed in an indoor handling facility on 6 separate occasions. At least one image was taken of each side of the head using a thermal infrared camera (FLIR E8 WiFi, FLIR, Wilsonville, OR). The distance at which the images were taken was approximately 1 m from the steer. The rectal temperature was used as the control method to compare thermal imaging data. After thermal image acquisition, images were analyzed using the FLIR ResearchIR Max software (v. 4.40.8.28, FLIR, Wilsonville, OR), with the regions of interest being the eye and nasal cavity.ResultsThe analysis focused on minimum (MIN), maximum (MAX), mean, standard deviation (SD), and range of temperatures in the regions of interest. The REG procedure in SAS (v. 9.4, SAS Institute, Inc., Cary, NC) was used to perform stepwise regression to predict rectal temperature from the outdoor temperature (OTEMP) and all imaging features. When OTEMP was greater than –17.8°C, the regression model contained OTEMP, left nasal MAX, left nasal SD, and left eye MAX temperature and right eye temperature range, with an R2 of 0.24. When OTEMP was above freezing (0°C), the regression model contained left nasal temperature range, right eye temperature range, and average nasal mean temperature, with an R2 increase to 0.50. When using all data, the regression model fit left nasal MAX, right nasal MIN, average nasal mean, and left eye MAX temperatures and right eye temperature range, with an R2 of 0.08. These results show that thermal imaging technology has higher prediction accuracy in warmer temperature ranges than extreme cold conditions.ConclusionMore validation research on this thermal imaging technology needs to be conducted at warmer temperatures since all the current data was collected on cold winter days and a large portion of U.S. cattle are reared in more temperate and warmer areas than North Dakota such as Nebraska, Kansas, Texas, Oklahoma, and Florida. Overall, these results show promise for using thermal imaging technology to help detect BRD in an earlier stage by detecting fever before other clinical signs of BRD are present.

Effect of Feeding a Low Vitamin a Diet to Beef Steers on Calpain 1 Activation during Meat Aging

ObjectivesThe objective of the study was to determine if a vitamin A deficient diet during beef finishing influences calpain 1 activation during meat aging.Materials and MethodsSixty-four steers of approximately 7 mo of age were subjected to a 14-d acclimation period followed by a 95-d growing period on a low vitamin A diet (1017 IU vitamin A/kg DM) designed to deplete liver vitamin A stores. Steers were assigned to a randomized complete blocked design with a 2 × 2 arrangement of treatments (breed: commercial Angus, n = 32, and purebred Simmental, n = 32; and a Low Vitamin A diet or a control diet). The low Vitamin A (LVA) treatment was a finishing diet with no supplemental vitamin A (723 IU vitamin A/kg DM). The control (CON) treatment was the LVA diet plus supplementation with 2200 IU vitamin A/kg DM for a total of 2923 IU vitamin A/kg DM. Serum retinol concentrations were monitored at the beginning and end of treatment. Upon completion of finishing, steers were slaughtered in two groups at a commercial plant. After fabrication, boneless strip loins (IMPS 180) were collected and transported to NDSU. Samples (approximately 40 g) were collected from the anterior portion of the strip loin on d-2 and d-7 of aging and immediately frozen. Protein was extracted from meat samples in fractionation buffers to yield sarcoplasmic and myofibrillar portions, separated by SDS-PAGE, and transferred to PVDF membranes. Immunoblot analysis was done using anti-desmin (d-2 and d-7) and anti-calpain 1 (d-2) antibodies, and results were visualized and documented. A pooled control was run on all membranes and set to a value of one for normalizing results. All experimental data were analyzed using the Proc Mixed procedure of SAS with breed of steers, dietary treatments, their interaction and slaughter date used as a fixed effect.ResultsCalpain 1 autolysis in the sarcoplasmic protein fraction of the d-2 aged loin samples were not affected by treatment or breed. The myofibrillar protein fraction from Angus loins had greater (P = 0.02) accumulation of the 76 kDa calpain 1 autolysis product than that from the Simmental loins; the myofibrillar fraction of the loins from the LVA treatment tended (P = 0.07) to have more 76 kDa calpain 1 autolysis product than that from the CON. There were not any differences (P > 0.19) in the 80 kDa calpain 1 band or the 78 kDa calpain 1 intermediate autolysis product in the myofibrillar fraction. There was a treatment by breed interaction (P = 0.01) for desmin in the d-7 aged loins where Angus loins from the CON treatment had less accumulation of the 46 kDa band than Angus loins on the LVA treatment and Simmental loins from either treatment.ConclusionVitamin A restriction increased protein proteolysis in Angus but not in Simmental steers. The increased calpain 1 autolysis in Angus vs. Simmental, regardless of Vitamin A treatment, indicates a genetic difference that may be the driver for the increased protein degradation in steers a restricted vitamin A diet.

Modelling methane emission mitigation by anaerobic digestion: effect of storage conditions and co-digestion

In this work the methane conversion factor (MCF) of untreated and anaerobically digested cattle manure (CM) as a function of storage temperature, time and co-digestion was measured in an in vitro experiment and modelled based on IPCC (2006) methodology (Tier 2). For this, one sample of untreated CM, one sample of mono-digested CM and three samples of CM co-digested with grass were incubated at seven different temperatures (from 5°C to 50°C) over 346 days. The main results showed that ultimate methane yield (B₀) of CM is higher than the B₀ reported by the IPCC (2006). Two temperature ranges should be considered for MCF evolution, below 15°C very low MCF was measured in this work for untreated CM, mono and co-digested samples. At higher temperatures, MCF obtained in this work and that provided by the IPCC could be comparable depending on storage time. Anaerobic mono-digestion decreased MCF compared to untreated CM at all temperatures and times, except in the temperature range between 20°C and 25°C if storage time is low, due to a lag phase observed in CM. This lag phase would probably not happen in real storage conditions depending on the proportion of old manure remaining in the storage tank. Co-digestion with grass-decreased MCF compared to mono-digestion, but increased CH₄ production in terms of fresh matter due to the higher B₀ of the mixture. Storage time, temperature and co-digestion should be considered in the quantification of CH₄ emission from digested material.

Model-informed drug development approach supporting approval of the 4-week (Q4W) dosing schedule for nivolumab (Opdivo) across multiple indications: a regulatory perspective

BACKGROUND

A nivolumab dosage regimen of 480 mg intravenously (i.v.) every 4 weeks (Q4W) was approved by FDA for the majority of the approved indications for nivolumab.

METHODS

The proposed new dosage regimen was supported by pharmacokinetic modeling and simulation, dose/exposure-response relationships for efficacy and safety in the indicated patient populations, and the clinical safety data with the 480 mg Q4W dosage regimen. Pharmacokinetic exposures achieved with 480 mg Q4W were predicted for 4166 patients in 21 clinical studies with various types of solid and hematological tumors. Exposure-response analyses were conducted to predict 480 mg Q4W safety and efficacy across all FDA-approved indications for nivolumab.

RESULTS

For the overall population, the geometric mean exposure achieved with 480 mg i.v. Q4W was 5.2% higher for steady state Cavg and 15.6% lower for Ctrough than those with 3 mg/kg i.v. Q2W, the approved dosage regimen. The simulated concentration-time course achieved with 480 mg Q4W regimen was below the median concentration achieved with 10 mg/kg i.v. Q2W that was also studied in clinical trials. The predicted probability of adverse events was similar between 480 mg Q4W and that observed with the 3 mg/kg Q2W regimen. Efficacy results were found to be similar between Q2W and Q3W dosage regimens in patients with renal cell carcinoma. The predicted efficacy for each indication suggested that the efficacy with 480 mg Q4W is unlikely to be compromised compared with that observed with 3 mg/kg Q2W.

CONCLUSIONS

The model-informed analyses of predicted exposure, efficacy and safety based on data from extensive clinical experience with nivolumab suggest that the benefit-risk profile of 480 mg Q4W regimen is comparable to the approved 3 mg/kg Q2W regimen, thus providing the regulatory basis for the approval of 480 mg Q4W regimen in the absence of clinical efficacy data with this new dosage regimen.

A primary germ cell tumour in the gastrointestinal tract: a caecal lesion of yolk-sac morphology in a young patient

A 24-year-old man with a history of Crohns disease, whilst undergoing surveillance colonoscopy was found to have an ulcerated caecal lesion. The histopathology from the mucosal biopsy was suggestive of a yolk sac tumour. After thorough re-examination, the patient had no radiological evidence of malignancy in his testes or retroperitoneum. His alpha-fetoprotein levels returned as 2145, whilst his carcinoembryonic antigen was negligible. The patient was therefore consented for and underwent a laparoscopic right hemi-colectomy with an ileocolic anastomosis, without any complications. The formal histopathology confirmed the results from the biopsy, of a yolk sac non seminous germ cell tumour with positive lymph nodes and lymphovascular invasion. The patient was referred on to medical oncology for neoadjuvant chemotherapy. As the literature in his instance is scarce, the patient's overall prognosis remains unclear. To the best of our knowledge this is the first reported primary germ cell tumour of the gastrointestinal tract.

A rapid method for the sequential separation of polonium, plutonium, americium and uranium in drinking water

A new sequential separation method for the determination of polonium and actinides (Pu, Am and U) in drinking water samples has been developed that can be used for emergency response or routine water analyses. For the first time, the application of TEVA chromatography column in the sequential separation of polonium and plutonium has been studied. This method utilizes a rapid Fe⁺³ co-precipitation step to remove matrix interferences, followed by plutonium oxidation state adjustment to Pu⁴⁺ and an incubation period of ~ 1 h at 50-60 °C to allow Po²⁺ to oxidize to Po⁴⁺. The polonium and plutonium were then separated on a TEVA column, while separation of americium from uranium was performed on a TRU column. After separation, polonium was micro-precipitated with copper sulfide (CuS), while actinides were micro co-precipitated using neodymium fluoride (NdF₃) for counting by the alpha spectrometry. The method is simple, robust and can be performed quickly with excellent removal of interferences, high chemical recovery and very good alpha peak resolution. The efficiency and reliability of the procedures were tested by using spiked samples. The effect of several transition metals (Cu²⁺, Pb²⁺, Fe³⁺, Fe²⁺, and Ni²⁺) on the performance of this method were also assessed to evaluate the potential matrix effects. Studies indicate that presence of up to 25 mg of these cations in the samples had no adverse effect on the recovery or the resolution of polonium alpha peaks.