Management of adult patients with haematological malignancies in critical care

There are a diverse range of haematological malignancies with varying clinical presentations and prognoses. Patients with haematological malignancy may require admission to critical care at the time of diagnosis or due to treatment related effects and complications. Although the prognosis for such patients requiring critical care has improved, there remain uncertainties in optimal clinical management. Identification of patients who will benefit from critical care admission is challenging and selective involvement of palliative care may help to reduce unnecessary and non-beneficial treatments. While patients with haematological malignancy can present a challenge to critical care physicians, good outcomes can be achieved. In this narrative review, we provide a brief overview of relevant haematological malignancies for the critical care physician and a summary of recent treatment advances. Subsequently, we focus on critical care management for the patient with haematological malignancy including sepsis; acute respiratory failure; prevention and treatment of tumour lysis syndrome; thrombocytopaenia; and venous thromboembolism. We also discuss immunotherapeutic-specific related complications and their management, including cytokine release syndrome and immune effector cell associated neurotoxicity syndrome associated with chimeric antigen receptor T-cell therapy. While the management of haematological malignancies is highly specialised and increasingly centralised, acutely unwell patients often present to their local hospital with complications requiring critical care expertise. The aim of this review is to provide a contemporary overview of disease and management principles for non-specialist critical care teams.

Healthcare utilisation and unmet health needs in children with intellectual disability: a propensity score matching approach using longitudinal cohort data

BACKGROUND

Health disparities for children with intellectual disabilities can be challenging to measure due to many other factors that can impact health and healthcare use. The aim of the current study was to use longitudinal cohort data to compare children with intellectual disability (ID) in Ireland between 2006 and 2014 on healthcare utilisation and unmet need, at ages 9 and 13, using a propensity score matching (PSM) approach.

METHODS

Using data from the Growing up in Ireland study, PSM was used to identify an appropriate control sample to compare with a sample of children with ID (n = 124). Participants were matched on variables that are known to influence healthcare utilisation to reduce the impact of confounding variables between groups so that differences between the groups can be estimated. Logistic regression was used to estimate effects at ages 9 and 13.

RESULTS

Children with ID were no more likely to have visited a general practitioner or emergency department in the past 12 months than children without ID. They did have a greater likelihood of visiting a doctor in a hospital in the past 12 months and of having an overnight stay in hospital by age 9. Primary caregivers of children with ID were more likely to report unmet health needs at ages 9 and 13.

CONCLUSIONS

This approach is a novel means of comparing healthcare use in this population by balancing the impact of other factors that may result in inequities, to which children with ID may be more vulnerable.

Paediatric hospital admissions for psychiatric and psychosocial reasons during the first year of the COVID-19 pandemic

Increases in youth psychiatric presentations to out-patient and emergency department settings during COVID-19 have been reported. This study, using data from five hospitals in Ireland, examines changes in the number and type of paediatric admissions during COVID-19 (March 2020 - February 2021) compared to the previous two years. ICD-10 classification was used to establish admissions with mental, behavioural, neuro-developmental disorders and psychosocial reasons (MBN-PS). Overall hospital admissions fell by 25.3%, while MBN-PS fell by only 2.6%, mostly during an initial lockdown. Admissions for MBN-PS increased in July-August (9.2%), increased further in September-December (28.3%), returning to pre-COVID-19 levels in January-February 2021. Significant increases were observed among youths with anorexia nervosa (47.8%), other eating disorders (42.9%), and admissions for anxiety (29.6%), with these effects relating to females only. Although admissions for self-harm increased (3%) and rates of ASD admissions reduced (17%), these were not statistically significant. The disproportionate increase in admissions for MBN-PS compared to medical admissions suggests an adverse effect of COVID-19 on youth mental health, for females in particular, and supports previous reports of a pandemic specific increase in eating psychopathology. Combined community and acute service delivery and capacity planning are urgently needed given the prior underfunding of services pre-pandemic.

Fluorescence lifetime imaging reveals regulation of presynaptic Ca2+ by glutamate uptake and mGluRs, but not somatic voltage in cortical neurons

Brain function relies on vesicular release of neurotransmitters at chemical synapses. The release probability depends on action potential-evoked presynaptic Ca2+ entry, but also on the resting Ca2+ level. Whether these basic aspects of presynaptic calcium homeostasis show any consistent trend along the axonal path, and how they are controlled by local network activity, remains poorly understood. Here, we take advantage of the recently advanced FLIM-based method to monitor presynaptic Ca2+ with nanomolar sensitivity. We find that, in cortical pyramidal neurons, action potential-evoked calcium entry (range 10-300 nM), but not the resting Ca2+ level (range 10-100 nM), tends to increase with higher order of axonal branches. Blocking astroglial glutamate uptake reduces evoked Ca2+ entry but has little effect on resting Ca2+ whereas both appear boosted by the constitutive activation of group 1/2 metabotropic glutamate receptors. We find no consistent effect of transient somatic depolarization or hyperpolarization on presynaptic Ca2+ entry or its basal level. The results unveil some key aspects of presynaptic machinery in cortical circuits, shedding light on basic principles of synaptic connectivity in the brain.

Nicotinic receptor activation induces NMDA receptor independent long-term potentiation of glutamatergic signalling in hippocampal oriens interneurons

KEY POINTS

Long-term potentiation of glutamatergic transmission to hippocampal interneurons in stratum oriens does not require NMDA receptors and the induction mechanisms are incompletely understood. Extracellular stimulation, conventionally used to monitor synaptic strength and induce long-term potentiation (LTP), does not exclusively recruit glutamatergic axons. We used optogenetic stimulation of either glutamatergic or cholinergic afferents to probe the relative roles of different signalling mechanisms in LTP induction. Selective stimulation of cholinergic axons was sufficient to induce LTP, which was prevented by chelating postsynaptic Ca2+ or blocking nicotinic receptors. The present study adds nicotinic receptors to the list of sources of Ca2+ that induce NMDA receptor independent LTP in hippocampal oriens interneurons.

ABSTRACT

Many interneurons located in stratum oriens of the rodent hippocampus exhibit a form of long-term potentiation (LTP) of glutamatergic transmission that does not depend on NMDA receptors for its induction but, instead, requires Ca2+ -permeable AMPA receptors and group I metabotropic glutamate receptors. A role for cholinergic signalling has also been reported. However, electrical stimulation of presynaptic axons, conventionally used to evoke synaptic responses, does not allow the relative roles of glutamatergic and cholinergic synapses in the induction of LTP to be distinguished. Here, we show that repetitive optogenetic stimulation confined to cholinergic axons is sufficient to trigger a lasting potentiation of glutamatergic signalling. This phenomenon shows partial occlusion with LTP induced by electrical stimulation, and is sensitive to postsynaptic Ca2+ chelation and blockers of nicotinic receptors. ACh release from cholinergic axons is thus sufficient to trigger heterosynaptic potentiation of glutamatergic signalling to oriens interneurons in the hippocampus.

Examining the obesity paradox: A moderating effect of fitness on adipose endocrine function in older adults

Despite evidence linking obesity with increased mortality, older adults with excessive adiposity seem protected, resulting in a so-called obesity paradox. Obesity is characterized by leptin resistance, which contributes to increased risk of all-cause mortality. Therefore, lifestyle factors, such as physical fitness, that lower leptin independent of adiposity may be confounding the obesity paradox. To investigate this, we evaluated whether physical fitness moderated the relationship between leptin and adiposity. We found older adults with higher fitness had lower body mass (r(39) = -0.43, p < 0.01), leptin (r(39) = -0.29, p = 0.03) and inflammation (IL-1β: (r(39) = -0.69, p < 0.01); TNF-α: (r(39) = -0.30, p = 0.03)). Fitness moderated the relationship between leptin and adiposity (F(5, 37) = 3.73, p < 0.01, R² = 0.33) to reveal the obesity paradox in moderately and high fit individuals (b = 216.24, t(37) = 1.46, p = 0.15; b= -88.10, t(37) = -0.49, p = 0.63) but not in low fit individuals. These results show the link between obesity and mortality may not be dependent on total adiposity, but rather on endocrine function and adipocyte leptin secretion. These results have important implications for older adults struggling to maintain healthy body composition and suggest that fitness may promote overall wellbeing.

Forward genetics identifies a novel sleep mutant with sleep state inertia and REM sleep deficits

Switches between global sleep and wakefulness states are believed to be dictated by top-down influences arising from subcortical nuclei. Using forward genetics and in vivo electrophysiology, we identified a recessive mouse mutant line characterized by a substantially reduced propensity to transition between wake and sleep states with an especially pronounced deficit in initiating rapid eye movement (REM) sleep episodes. The causative mutation, an Ile102Asn substitution in the synaptic vesicular protein, VAMP2, was associated with morphological synaptic changes and specific behavioral deficits, while in vitro electrophysiological investigations with fluorescence imaging revealed a markedly diminished probability of vesicular release in mutants. Our data show that global shifts in the synaptic efficiency across brain-wide networks leads to an altered probability of vigilance state transitions, possibly as a result of an altered excitability balance within local circuits controlling sleep-wake architecture.

Factors that influence family and parental preferences and decision making for unscheduled paediatric healthcare - systematic review

INTRODUCTION

Health systems offer access to unscheduled care through numerous routes; however, it is typically provided by general practitioners (GPs), by emergency medicine doctors in in emergency departments (EDs) and by GPs in out-of-hours GP services such as practitioner cooperatives. Unscheduled healthcare constitutes a substantial portion of healthcare delivery. A systematic review was conducted to establish the factors that influence parents' decision making when seeking unscheduled healthcare for their children. The systematic review question was "What are the factors that influence the decision making of parents and families seeking unscheduled paediatric healthcare?"

METHOD

Five databases (CINAHL, PubMed, SCOPUS, PsycInfo, EconLit) and four grey literature databases (Proquest, Lenus, OpenGrey, Google Scholar) were searched. The titles and abstracts of 3746 articles were screened and full-text screening was performed on 177 of these articles. Fifty-six papers were selected for inclusion in the review. Data relating to different types of unscheduled health services (namely primary care, the emergency department and out-of-hours services) were extracted from these articles. A narrative approach was used to synthesise the extracted data.

RESULTS

Several factors were identified as influencing parental preferences and decision making when seeking unscheduled healthcare for their children. A number of the included studies identified pre-disposing factors such as race, ethnicity and socioeconomic status (SES) as impacting the healthcare-seeking behaviour of parents. Unscheduled healthcare use was often initiated by the parent's perception that the child's condition was urgent and their need for reassurance. The choice of unscheduled service was influenced by a myriad of factors such as: waiting times, availability of GP appointments, location of the ED, and the relationship that the parent or caregiver had with their GP.

CONCLUSION

Policy and planning initiatives do not always reflect how patients negotiate the health system as a single entity with numerous entry points. Altering patients' behaviour through public health initiatives that seek to improve, for instance, health literacy or reducing emergency hospital admissions through preventative primary care requires an understanding of the relative importance of factors that influence behaviour and decision making, and the interactions between these factors.

The dietary impact of the Norman Conquest: A multiproxy archaeological investigation of Oxford, UK

Archaeology has yet to capitalise on the opportunities offered by bioarchaeological approaches to examine the impact of the 11th-century AD Norman Conquest of England. This study utilises an integrated multiproxy analytical approach to identify and explain changes and continuities in diet and foodways between the 10th and 13th centuries in the city of Oxford, UK. The integration of organic residue analysis of ceramics, carbon (δ13C) and nitrogen (δ15N) isotope analysis of human and animal bones, incremental analysis of δ13C and δ15N from human tooth dentine and palaeopathological analysis of human skeletal remains has revealed a broad pattern of increasing intensification and marketisation across various areas of economic practice, with a much lesser and more short-term impact of the Conquest on everyday lifestyles than is suggested by documentary sources. Nonetheless, isotope data indicate short-term periods of instability, particularly food insecurity, did impact individuals. Evidence of preferences for certain foodstuffs and cooking techniques documented among the elite classes were also observed among lower-status townspeople, suggesting that Anglo-Norman fashions could be adopted across the social spectrum. This study demonstrates the potential for future archaeological research to generate more nuanced understanding of the cultural impact of the Norman Conquest of England, while showcasing a method which can be used to elucidate the undocumented, everyday implications of other large-scale political events on non-elites.

Preparation of dissociated mouse primary neuronal cultures from long-term cryopreserved brain tissue

BACKGROUND

Dissociated primary neuronal cultures are widely used as a model system to investigate the cellular and molecular properties of diverse neuronal populations and mechanisms of action potential generation and synaptic transmission. Typically, rodent primary neuronal cultures are obtained from freshly-dissociated embryonic or postnatal brain tissue, which often requires intense animal husbandry. This can strain resources when working with genetically modified mice.

NEW METHOD

Here we describe an experimental protocol for frozen storage of mouse hippocampi, which allows fully functional dissociated primary neuronal cultures to be prepared from cryopreserved tissue.

RESULTS

We show that thawed hippocampal neurons have functional properties similar to those of freshly dissociated neurons, including neuronal morphology, excitability, action potential waveform and synaptic neurotransmitter release, even after cryopreservation for several years.

COMPARISON TO THE EXISTING METHODS

In contrast to the existing methods, the protocol described here allows for efficient long-term storage of samples, allowing researchers to perform functional experiments on neuronal cultures from brain tissue collected in other laboratories.

CONCLUSIONS

We anticipate that this method will facilitate collaborations among laboratories based at distant locations and will thus optimise the use of genetically modified mouse models, in line with the 3Rs (Replacement, Reduction and Refinement) recommended for scientific use of animals in research.

Moving toward the elimination of cervical cancer: modelling the health and economic benefits of increasing uptake of human papillomavirus vaccines

Background

The human papillomavirus (hpv) is a common sexually transmitted infection and a primary cause of cervical cancer. The Government of Canada has set a target of reaching 90% hpv vaccine coverage among adolescents by 2025. Here, we examine hpv vaccine uptake in school-based immunization programs across Canada and explore how achieving the 90% target could affect the future incidence of cervical cancer, mortality, and health system expenditures in a cohort of Canadian women.

Methods

Data for hpv vaccine uptake in the most recent reported school year available in each jurisdiction were provided in 2017 by jurisdictional school-based immunization programs and were used to estimate a national weighted average of 67%. The OncoSim microsimulation model (version 2.5) was used to compare 3 different levels of hpv vaccine uptake (0%, 67%, 90%) on health and economic outcomes for a hypothetical cohort of all 5- to 10-year-old girls in Canada in 2015.

Results

Vaccine uptake for girls in school-based programs varied from 55.0% to 92.0% in the jurisdictions reviewed. The OncoSim model projects that increasing uptake to 90% from 67% would result in a 23% reduction in cervical cancer incidence rates (to 3.1 cases from 4.0 cases per 100,000, averaged across the lifetime of the cohort) and a 23% decline in the average annual mortality rate (to 1.0 deaths from 1.3 deaths per 100,000). Finally, the model projects that the health system will incur a cost of $9 million (1% increase) during the lifetime of the cohort if uptake is increased to 90% from 67%. Costs are discounted (1.5%) and expressed in 2016 Canadian dollars. Costs reflect the payer perspective.

Conclusions

Our model shows that increasing hpv vaccine uptake to 90% from current levels for girls in school-based immunization programs could result in substantial reductions in the future incidence and mortality rates for cervical cancer in Canada.

Analogue closed-loop optogenetic modulation of hippocampal pyramidal cells dissociates gamma frequency and amplitude

Gamma-band oscillations are implicated in modulation of attention, integration of sensory information and flexible communication among anatomically connected brain areas. How networks become entrained is incompletely understood. Specifically, it is unclear how the spectral and temporal characteristics of network oscillations can be altered on rapid timescales needed for efficient communication. We use closed-loop optogenetic modulation of principal cell excitability in mouse hippocampal slices to interrogate the dynamical properties of hippocampal oscillations. Gamma frequency and amplitude can be modulated bi-directionally, and dissociated, by phase-advancing or delaying optogenetic feedback to pyramidal cells. Closed-loop modulation alters the synchrony rather than average frequency of action potentials, in principle avoiding disruption of population rate-coding of information. Modulation of phasic excitatory currents in principal neurons is sufficient to manipulate oscillations, suggesting that feed-forward excitation of pyramidal cells has an important role in determining oscillatory dynamics and the ability of networks to couple with one another.

T-type calcium channels contribute to NMDA receptor independent synaptic plasticity in hippocampal regular-spiking oriens-alveus interneurons

KEY POINTS

Regular-spiking interneurons in the hippocampal stratum oriens exhibit a form of long-term potentiation of excitatory transmission that is independent of NMDA receptors but requires co-activation of Ca²⁺ -permeable AMPA receptors and group I metabotropic glutamate receptors. We show that T-type Ca²⁺ channels are present in such interneurons. Blockade of T-type currents prevents the induction of long-term potentiation, and also interferes with long-lasting potentiation induced either by postsynaptic trains of action potentials or by pairing postsynaptic hyperpolarization with activation of group I metabotropic receptors. Several Ca²⁺ sources thus converge on the induction of NMDA receptor independent synaptic plasticity.

ABSTRACT

NMDA receptor independent long-term potentiation (LTP) in hippocampal stratum oriens-alveus (O/A) interneurons requires co-activation of postsynaptic group I metabotropic glutamate receptors (mGluRs) and Ca²⁺ -permeable AMPA receptors. The rectification properties of such AMPA receptors contribute to the preferential induction of LTP at hyperpolarized potentials. A persistent increase in excitatory transmission can also be triggered by exogenous activation of group I mGluRs at the same time as the interneuron is hyperpolarized, or by postsynaptic trains of action potentials in the absence of presynaptic stimulation. In the present study, we identify low-threshold transient (T-type) channels as a further source of Ca²⁺ that contributes to synaptic plasticity. T-type Ca²⁺ currents were detected in mouse regular-spiking O/A interneurons. Blocking T-type currents pharmacologically prevented LTP induced by high-frequency stimulation of glutamatergic axons, or by application of the group I mGluR agonist dihydroxyphenylglycine, paired with postsynaptic hyperpolarization. T-type current blockade also prevented synaptic potentiation induced by postsynaptic action potential trains. Several sources of Ca²⁺ thus converge on NMDA receptor independent LTP induction in O/A interneurons.

Transporting Forensic Psychiatric Patients

Patients in a forensic psychiatric facility often require escorted transport to medical facilities for investigations or treatments of physical health ailments. Transporting these patients presents significant safety and custody challenges because of the nature of patients housed in forensic psychiatric facilities. A significant proportion of these patients may be transfers from the Department of Corrections (DOC) under legal mandates for psychiatric evaluation and treatment better provided in a hospital setting, and most of them will return to the DOC. Although departments of correction have protocols for escorting these potentially dangerous individuals, it is unclear whether receiving psychiatric hospitals have established procedures for maintaining the safety of others and custody of these individuals during transportation outside the hospital facility. The literature is sparse on precautions to be observed when transporting dangerous forensic psychiatric patients, including those with high escape risk. In this article, we describe one forensic inpatient facility's procedure for determining the appropriate level needed to transport these individuals outside of the forensic facility. We also describe the risk assessment procedure for determining level of transport. These are quality improvement measures resulting from a critical review of an incident of escape from the forensic facility several years ago.

Long-term potentiation in hippocampal oriens interneurons: postsynaptic induction, presynaptic expression and evaluation of candidate retrograde factors

Several types of hippocampal interneurons exhibit a form of long-term potentiation (LTP) that depends on Ca²⁺-permeable AMPA receptors and group I metabotropic glutamate receptors. Several sources of evidence point to a presynaptic locus of LTP maintenance. The retrograde factor that triggers the expression of LTP remains unidentified. Here, we show that trains of action potentials in putative oriens-lacunosum-moleculare interneurons of the mouse CA1 region can induce long-lasting potentiation of stimulus-evoked excitatory postsynaptic currents that mimics LTP elicited by high-frequency afferent stimulation. We further report that blockers of nitric oxide production or TRPV1 receptors failed to prevent LTP induction. The present results add to the evidence that retrograde signalling underlies N-methyl-d-aspartate (NMDA) receptor-independent LTP in oriens interneurons, mediated by an unidentified factor.

Colorectal cancer screening in Canada: results from the first round of screening for five provincial programs

BACKGROUND

Early implementation of programmatic colorectal cancer (crc) screening for average-risk individuals 50-74 years of age in Canada has used fecal occult blood tests [fts (guaiac or immunochemical)] and colonoscopy for follow-up of abnormal fts. This paper presents results of an evaluation of this crc screening.

METHODS

Five Canadian provincial programs provided aggregated data for individuals with a first-round ft processed between January 1, 2009, and December 31, 2011.

RESULTS

The 104,750 people who successfully completed a first round of screening represented 16.1% of those who had access to the programs between January 1, 2009, and December 31, 2011 (mean age: 61.2 years; men: 61.4 years; women: 61.1 years). Of those participants, 4661 had an abnormal ft (4.4%). Uptake of colonoscopy within 180 days after an abnormal ft was 80.5%, ranging from 67.8% to 89.5% by program. The positive predictive value (ppv) for adenoma was 35.9% for guaiac ft and 50.6% for immunochemical ft. Adenoma and crc detection rates were, respectively, 16.9 and 1.8 per 1000 screened. Of invasive crcs detected, 64.6% were stage i or ii.

CONCLUSIONS

Considering the variation in characteristics and stage of implementation of each provincial program, the collaboration of the provinces leading to this report on the early performance of crc screening in Canada is a major milestone. Targets are met or nearly met for significant indicators such as ppv for adenoma and cancer detection rate. Participation is expected to increase as programs are fully implemented in the provinces. Additional effort may be needed to improve timely access to follow-up colonoscopy.

SUPPORTING CHILDREN IN U.S. LEGAL PROCEEDINGS: Descriptive and Attitudinal Data From a National Survey of Victim/Witness Assistants

We conducted a national survey of 786 victim/witness assistants (VWAs) to provide descriptive and attitudinal information about support person use in U.S. legal proceedings involving children. VWAs (N = 414) from 46 states returned completed surveys (response rate = 53%). Prosecutor-based VWAs or parents/guardians most frequently served as support persons. One support person was almost always or often used with child victims and/or witnesses of all ages. Support persons were extremely common in cases involving child sexual abuse, physical abuse, neglect, and adult domestic violence. Overall, support persons provided more informational than emotional support. The most common informational support was to provide referrals to community resources, conduct courtroom visit/orientation, and disseminate relevant procedural information. The most common emotional support was to accompany the child to trial. Support persons rarely or never questioned children directly during investigative interviews or in court. Respondents believed support persons decrease children's stress and increase accuracy and credibility; however, this effect varied as a function of who provided support, child age, case type, and type of emotional or informational support. Respondents believed that support person presence at trial probably does not prejudice jurors against defendants. These survey data provide a benchmark for legal professionals and a foundation for future social scientific research examining the effects of support person use on children.

Probing the morphology-device relation of Fe₂O₃ nanostructures towards photovoltaic and sensing applications

A lot of research on nanomaterials has been carried out in recent years. However, there is still a lack of nanostructures that have a combination of superior properties; both efficient electron transport and high surface area. Here, the authors have tried to develop hybrid α-Fe(2)O(3) flower-like morphology which exhibits both superior electron transport and high surface area. Intrigued by the unique properties of Fe(2)O(3) at the nanoscale and its abundance in nature, we have demonstrated a facile template-free solution based synthesis of hybrid α-Fe(2)O(3) comprising nanopetals nucleating radially from a 3D core. Due to its simplicity, the synthesis process can be easily reproduced and scaled up. We carried out in-depth studies on gas sensing and dye-sensitized solar cell (DSSC) device characterization so as to gain an understanding of how surface area and transport properties are affected by variation in morphology. The hybrid α-Fe(2)O(3) nanostructures are studied as potential candidates for gas sensors and for the first time as a working electrode for DSSC.

Plasticity of face processing in infancy

Experience plays a crucial role for the normal development of many perceptual and cognitive functions, such as speech perception. For example, between 6 and 10 months of age, the infant's ability to discriminate among native speech sounds improves, whereas the ability to discriminate among foreign speech sounds declines. However, a recent investigation suggests that some experience with non-native languages from 9 months of age facilitates the maintenance of this ability at 12 months. Nelson has suggested that the systems underlying face processing may be similarly sculpted by experience with different kinds of faces. In the current investigation, we demonstrate that, in human infants between 6 and 9 months of age, exposure to non-native faces, in this case, faces of Barbary macaques (Macaca sylvanus), facilitates the discrimination of monkey faces, an ability that is otherwise lost around 9 months of age. These data support, and further elucidate, the role of early experience in the development of face processing.

Analgesia for day-case shoulder surgery

BACKGROUND

Single-shot nerve blocks provide excellent postoperative analgesia for a limited period and are increasingly used in day-case units. They allow early patient discharge following painful operative procedures that would otherwise require overnight hospitalization. We investigated the adequacy of analgesia at home after the block had worn off.

METHODS

A prospective audit by telephone 1 week after surgery of 50 consecutive patients who had had a single-shot interscalene block for day-case shoulder arthroscopic surgery.

RESULTS

The mean length of adequate sensory block was 22.5 h (9-48 h) after which 20% of patients had a maximum visual analogue scale (VAS) score of 5/5. Most patients did not take analgesics as prescribed and two patients (5.4%) required additional analgesia from their family doctor or accident and emergency department.

CONCLUSIONS

We conclude that analgesia at home is often inadequate after painful day-case surgical procedures if single-shot local anaesthetic blockade is used.

Community data--where does the value lie? Assessing confidence limits of community collected water quality data

Waterwatch is a national community-based monitoring network that aims to involve community groups and individuals in the protection and management of waterways. Waterwatch Victoria has the dual objectives of catchment education and water quality monitoring. The educational outcomes are evident, with the Waterwatch programme facilitating over 9,000 students to monitor more than 2,000 sites in waterways in 2000. This paper aims to assess the scientific value of community-collected data, through examining differences between Waterwatch data and professionally collected data. The study looked at all aspects of volunteer data collection, including data confidence protocols, equipment, and data analysis. All professional data was collated by the Victorian Water Quality Monitoring Network (VWQMN). The parameters examined in this study were turbidity, electrical conductivity (EC), pH and total phosphorus. The level of agreement between community-collected data and professional data varied temporally and spatially. Waterwatch data for EC and pH appeared to be very similar to professionally collected data. Equipment used by Waterwatch volunteers for turbidity and total phosphorus appeared to be limited in accuracy to moderate ranges. Overall the VWQMN professionally collected data showed less variance, suggesting greater variability, potentially due to inaccuracies, in volunteer collected data

Positron emission tomography scanning in malignant melanoma

BACKGROUND

Several recent studies have demonstrated the low yield of anatomically based computed tomography scans in evaluating Stage III (American Joint Committee on Cancer) patients with malignant melanoma. The purpose of this study was to investigate the efficacy and clinical utility of functionally based positron emission tomography (PET) scans in the same patient population.

METHODS

A prospective evaluation of 106 whole body PET scans obtained after injection of 2-fluorine-18, 2-fluoro-2-deoxy-D-glucose (FDG) was performed in 95 patients with clinically evident Stage III lymph node and/or in-transit melanoma. Areas of abnormality on FDG PET scanning were identified visually as foci of increased metabolic activity compared with background, and all positive foci were assessed pathologically.

RESULTS

In this patient population, there were 234 areas that were evaluated pathologically of which 165 were confirmed histologically to be melanoma. PET scanning identified 144 of the 165 areas of melanoma for a sensitivity of 87.3%. The 21 areas of melanoma that were missed included 10 microscopic foci, 9 foci less than 1 cm, and 2 foci greater than 1 cm. There were 39 areas of increased PET activity that were not associated with malignancy for a 78.6% predictive value of a positive test. Of the 39 false-positive areas (false-positive rate of 56.5%), 13 could be attributed to recent surgery, 3 to arthritis, 3 to infection, 2 to superficial phlebitis, 1 to a benign skin nevus, and 1 to a colonic polyp. Pathologic evaluation of the remaining false-positive areas failed to reveal a definitive etiology for their increased activity on PET scan. With the application of pertinent clinical information, the predictive value of a positive PET scan could be improved to 90. 6%. The specificity of PET scanning in this study was only 43.5% because very few prophylactic lymph node dissections were performed. Thirty-six of the total 183 abnormal areas (19.7%) on PET scanning proved to be unsuspected areas of metastatic disease. These findings led to a change in the planned clinical management in patients after 16 of the 106 PET scans (15.1%).

CONCLUSIONS

FDG PET scanning can be helpful in managing patients with Stage III melanoma in whom further surgery is contemplated. Although false-positive areas are not uncommon, PET scans did change the management of patients 15% of the time. PET's inability to identify microscopic disease suggests that it is of limited use in evaluating patients with Stage I-II disease.

Are altered pharmacokinetics of non-steroidal anti-inflammatory drugs (NSAIDs) a risk factor for gastrointestinal bleeding?

AIMS

We hypothesised that pharmacokinetic factors might go some way to explaining the risk of major gastrointestinal haemorrhage with non-steroidal anti-inflammatory drugs (NSAIDs), with bleeders exhibiting a reduced clearance of NSAIDs compared with non-bleeders and set out to investigate this.

METHODS

Fifty patients presenting to hospital with acute gastrointestinal bleeding while taking piroxicam, indomethacin, diclofenac or naproxen and age, sex, musculoskeletal disease and drug matched community dwelling controls, up to two for each index case, who had not bled were recruited. Clinical details including duration of therapy were recorded. Bleeders discontinued the implicated NSAID at presentation, controls at least five half-lives before the study. Bleeders were contacted by letter 1 month after discharge and invited to take part and were studied after a median delay of 5 months. Subjects received an oral dose of their respective NSAID and venous blood was sampled, over a period determined by the half-life of the NSAID. Plasma concentrations were determined by high performance liquid chromatography.

RESULTS

The median length of treatment for the index patients was 1 year (range 2 weeks--28 years) and for the control patients 2 years (1 month--25 years), P<0.0005. There were no significant differences in peak plasma concentration, time to peak plasma concentration or area under the plasma concentration-time curve between bleeders or controls for any of the NSAIDs studied, apart from piroxicam Cmax being lower in bleeders at 2.07 mg l(-1) than in controls at 3.21 mg l(-1), mean difference (95% CI) -1.14 (-1.83 - -0.48), P<0.005.

CONCLUSIONS

The data failed to support the hypothesis that reduced clearance of NSAIDs, which results in higher plasma concentrations, is a risk factor for acute gastrointestinal haemorrhage.

Endothelial cell adhesion molecules in psoriasis

Skin biopsies from patients with psoriasis and normal controls were examined for the expression of cell adhesion molecules including intercellular adhesion molecule-1 (ICAM-1), endothelial leukocyte adhesion molecule-1 (ELAM-1), HECA-452 and 4D10, using an immunoperoxidase techique. This study demonstrates that psoriatic skin exhibits a wide variety of markers of endothelial cell activation which are either induced or increased in expression (ICAM-1, ELAM-1 & 4D10). Moreover, ICAM-1 & HECA-452 are also expressed on leukocytes. These antigens may facilitate the adhesion of inflammatory cells to endothelium and antigen-presenting cells in psoriatic skin. Thus, they may play a role in faciliating the infiltration of leukocytes into psoriatic skin.

The influence of ciprofloxacin on the pharmacokinetics and pharmacodynamics of a single dose of temazepam in the young and elderly

The effect of pretreatment with a 4-day course of ciprofloxacin (500 mg twice daily) on the pharmacokinetics and pharmacodynamics of a single oral dose of temazepam (10 mg) was investigated in 12 healthy young and nine elderly patient volunteers in a crossover design study. Temazepam clearance was lower in the elderly than in the young, but this difference was not statistically significant. Ciprofloxacin had no significant effect on temazepam pharmacokinetics or pharmacodynamics in either age group.

Identification of a human endothelial cell activation antigen that is co-expressed by germinal follicle centre B lymphocytes

Endothelial cell activation antigens may play important roles in immune responses and in inflammation. This report describes the identification and characterization of a monoclonal antibody, named EAA-B, which reacts specifically with human umbilical vein endothelial (HUVE) cells pre-treated with tumour necrosis factor-alpha (TNF-alpha) but not with untreated cells. The expression of the EAA-B antigen on HUVE cells could also be induced by interleukin-1 (IL-1), bacterial lipopolysaccharide (LPS), and phorbol esters but not by interferon-gamma (IFN-gamma). By contrast, EAA-B antigen expression on neonatal foreskin and rheumatoid synovial fibroblasts, whether pre-treated with TNF-alpha or not, was not detectable. Peripheral blood leucocytes and the leukaemic cell lines U937, HL-60, Raji and Molt 4 showed no detectable expression of the EAA-B antigen. Kinetic studies demonstrated that the EAA-B antigen was rapidly expressed, peaked at 6 hr and declined to basal level by 24 hr. Western blotting revealed that monoclonal antibody EAA-B recognized a polypeptide of approximately 80,000-90,000 MW. EAA-B partially blocked the augmented adhesion of HL-60 cells to TNF-treated HUVE cells. However, it failed to inhibit the enhanced binding of peripheral blood leucocytes, U937, Raji and Molt 4 Cells to TNF-treated HUVE cells. In situ, the EAA-B antigen was detected on some vascular endothelium in tonsils, lymph nodes, psoriatic skin and rheumatoid synovium but not in normal non-lymphoid tissues. Interestingly EAA-B antigen is also expressed by B lymphocytes in germinal follicle centres (GFC) of lymphoid tissues. The co-expression of this endothelial activation antigen by GFC B lymphocytes may have significant implications for immune responses and in B-lymphocyte differentiation.

An evaluation of buffered aspirin and aspirin tablets in postoperative pain after third molar surgery

1. Single doses (500 and 1000 mg) of both buffered aspirin and aspirin tablets were compared with placebo in a randomised double-blind trial of parallel design in patients with postoperative pain after third molar surgery. 2. Only buffered aspirin 500 mg provided significant pain relief (P = 0.016) during the 5 h investigation period. 3. A significant correlation (P = 0.004) was observed between overall pain scores after the various aspirin treatments and aspirin esterase activity. 4. Buffered aspirin preparations afforded a slight advantage over aspirin tablets in the control of postoperative pain after third molar surgery. However, the duration of analgesia was short (approximately 2 h). 5. Aspirin esterase activity appears to be an important determinant of the drug's efficacy in postoperative dental pain.

Hyaline membrane disease and early neonatal aldosterone metabolism in infants of less than 33 weeks gestation

We studied urine excretion of free and conjugated aldosterone by 12 control infants and 14 infants with hyaline membrane disease (HMD) on the first and seventh days after birth. Both groups had a mean gestational age of 29 weeks. Total urine aldosterone excretion (UAE) and percent excreted as conjugate were similar for both groups on both study days, and did not relate to the severity of respiratory failure in infants with HMD. Sodium intake was higher for infants with HMD on both study days (p less than 0.02), but their urine sodium excretion was only significantly (p less than 0.01) higher on day 7. For total UAE values greater than 3 nmol/kg/d, there was no significant difference between estimated sodium-potassium exchange by control (22 +/- 5%, n = 8) and HMD (31 +/- 5%, n = 10) groups. These data suggest that neither the magnitude of excretion of aldosterone in the urine, the ability to conjugate aldosterone nor the degree of relative distal tubular unresponsiveness to aldosterone are related to the severity of pulmonary immaturity in preterm infants.

The association of age with aspirin esterase activity in human liver

The activity of the phase 1 enzyme aspirin esterase was studied in liver tissue from 16 patients, aged 45-88 years. No correlation between age and enzyme activity was found in post-mitochondrial, cytosolic and microsomal fractions. These results provide further evidence that age is not a major determinant of the activity of hepatic drug-metabolizing enzymes in man.

Benorylate hydrolysis by human plasma and human liver

1. Benorylate (4-acetamido phenyl-O-acetylsalicylate) hydrolysis in vitro by human plasma and by human liver microsomes and cytosol has been investigated. 2. Benorylate was hydrolysed by a route involving initial hydrolysis of the acetyl group to yield phenetsal followed by hydrolysis to paracetamol and salicylate. Hydrolysis via acetylsalicylate was minor. 3. Benorylate was more actively hydrolysed by liver cytosol than microsomes and about 10 times faster than plasma. 4. Following a single oral dose benorylate (4 g) to volunteers only salicylate and paracetamol were detected in the plasma. 5. The therapeutic effects of benorylate appear to be mediated by salicylate and paracetamol.

Human liver and plasma aspirin esterase

The plasma, in addition to the liver, is a major site of hydrolysis of aspirin. Human plasma and liver aspirin esterase activities in samples from a group of patients varied over a two fold range and there was a significant correlation between individual plasma and liver activities. Human liver aspirin esterase was present in the cytosolic and microsomal fractions. Cytosolic and microsomal enzymes had different activities and apparent affinities for aspirin.

The efficacy of benorylate in postoperative dental pain

The efficacy of a single pre-operative dose of benorylate (4 g) was determined in a double-blind, randomized, placebo-controlled parallel study in patients undergoing removal of a single impacted lower third molar. Patients treated with benorylate 4 g reported significantly less pain between 3-6 h after dosage than those treated with placebo. Overall pain scores at 6 h were significantly less in the benorylate group than the placebo group. However, overall pain scores at 12 h did not differ significantly between treatment groups. It is concluded from this study that a single dose of benorylate 4 g given immediately prior to the removal of an impacted lower third molar provides limited pain control during the postoperative period.

Sodium-renin-aldosterone relations in normal and hypertensive pregnancy

To examine the short-term regulation of sodium excretion, plasma volume, and the renin-aldosterone system in pregnancy, women in their first pregnancy received either a high-salt (HS) (250 mmol/day) or a low-salt (LS) (20 mmol/day) diet for 7 days during the second and third trimester and after delivery (total 213 studies). Twenty women, studied while normotensive during mid-pregnancy, developed pregnancy-induced hypertension (PIH) in the third trimester. There was slightly greater difficulty adapting to sodium depletion (LS diet) during normal pregnancy compared with postpartum. The final mean values for sodium excretion were 27 (SE 2), 28 (SE 3) and 14 (SE 4) mmol/day in the second and third trimester and postpartum respectively. Sodium excretion with the HS diet was similar at all stages and plasma volumes were maintained as effectively during pregnancy as after delivery following both diets. Plasma renin activity (PRA) and aldosterone concentration rose and fell significantly following the LS and HS diets but the sensitivity of renin response to changes in salt intake was blunted during normal pregnancy. Women who later developed PIH, when studied whilst normotensive, failed to stimulate plasma aldosterone after salt depletion in their second trimester and did not exhibit the 'sodium-independent' component of PRA seen in continuously normotensive subjects at this stage.