Complications of fibrotic interstitial lung disease for the general radiologist

Interstitial lung diseases (ILDs) are a heterogeneous group of conditions characterised by non-infective inflammation and scarring of the lung parenchyma. They are not infrequently encountered by the general radiologist in both acute and outpatient reporting settings who may even be the first to make the diagnosis. In the acute setting, patients with ILD can present with respiratory deterioration due to a number of causes and in addition to the common causes of dyspnoea, an acute exacerbation of ILD needs to be considered. An exacerbation can be initiated by common triggers such as infection, pulmonary embolism (PE), and heart failure, and it can also be initiated by an insult to the lung or occur due to an unknown cause. Particular care needs to be taken when interpreting computed tomography (CT) examinations in these patients as the findings of an acute exacerbation are non-specific and patient and technical factors can cause spurious appearances including dependent changes, breathing artefact and contrast medium opacification. In the non-acute setting, patients with ILD are at increased risk of lung cancer and pulmonary hypertension (PH), with lung cancer being a particularly important consideration as treatments carry the risk of triggering an acute exacerbation or deterioration in lung function. Overall, this review aims to provide an overview for the general radiologist of additional factors to consider when interpreting scans in patients with ILD and how the presence of ILD impacts the differential diagnoses and complications that can occur in these patients in both acute and non-acute settings.

1665 Characterising the Escalation in Hospital Trauma Admission During the Easing of the COVID-19 Level 4 Lockdown Restrictions

Introduction

Major trauma reduced by over a third during the institution of UK level-4 national lockdown (Rajput K. et al; 2020). Easing of lockdown on a societal level posed unprecedented uncertainties. With the easing of restrictions, it is expected that the quantity of trauma would increase. In the absence of ‘normality’ it remains uncertain about the extent of the quantity, severity and aetiology of the trauma. The effect of lockdown easing on patterns of traumatic admissions has not been studied and it has important implications upon service provision.

Method

A retrospective cohort study using the data from 2017-2019 were used as a 3-year control to compare each month of 2020. Regional trauma data (TARN data) from Aintree level-1 Major Trauma Centre, the regional tertiary Specialist Units. Easing of restrictions to the regional tier system began in May-July. This index 3months was compared to the control data.

Results

Following easing of restrictions there was a significant increase in the Incident Severity Scores from trauma admissions. The %mortality during the level-4 lockdown decreases but as restrictions are eased there is an increase in the % mortality. The number of stabbings and road traffic collisions are also seen to increase following the ease of restrictions.

Conclusions

There is a decrease in the number of trauma calls seen following the easing of restrictions, yet the severity of the incident and the mortality rate has increased. Therefore, is the trauma more severe of does COVID-19 influence this?

The use of continuous electronic prescribing data to infer trends in antimicrobial consumption and estimate the impact of stewardship interventions in hospitalized children

Background

Understanding antimicrobial consumption is essential to mitigate the development of antimicrobial resistance, yet robust data in children are sparse and methodologically limited. Electronic prescribing systems provide an important opportunity to analyse and report antimicrobial consumption in detail.

Objectives

We investigated the value of electronic prescribing data from a tertiary children’s hospital to report temporal trends in antimicrobial consumption in hospitalized children and compare commonly used metrics of antimicrobial consumption.

Methods

Daily measures of antimicrobial consumption [days of therapy (DOT) and DDDs] were derived from the electronic prescribing system between 2010 and 2018. Autoregressive moving-average models were used to infer trends and the estimates were compared with simulated point prevalence surveys (PPSs).

Results

More than 1.3 million antimicrobial administrations were analysed. There was significant daily and seasonal variation in overall consumption, which reduced annually by 1.77% (95% CI 0.50% to 3.02%). Relative consumption of meropenem decreased by 6.6% annually (95% CI −3.5% to 15.8%) following the expansion of the hospital antimicrobial stewardship programme. DOT and DDDs exhibited similar trends for most antimicrobials, though inconsistencies were observed where changes to dosage guidelines altered consumption calculation by DDDs, but not DOT. PPS simulations resulted in estimates of change over time, which converged on the model estimates, but with much less precision.

Conclusions

Electronic prescribing systems offer significant opportunities to better understand and report antimicrobial consumption in children. This approach to modelling administration data overcomes the limitations of using interval data and dispensary data. It provides substantially more detailed inferences on prescribing patterns and the potential impact of stewardship interventions.

Sensor Noise in LISA Pathfinder: In-Flight Performance of the Optical Test Mass Readout

We report on the first subpicometer interferometer flown in space. It was part of ESA's Laser Interferometer Space Antenna (LISA) Pathfinder mission and performed the fundamental measurement of the positional and angular motion of two free-falling test masses. The interferometer worked immediately, stably, and reliably from switch on until the end of the mission with exceptionally low residual noise of 32.0_{-1.7}^{+2.4}  fm/sqrt[Hz], significantly better than required. We present an upper limit for the sensor performance at millihertz frequencies and a model for the measured sensitivity above 200 mHz.

Cytologic grading of primary malignant salivary gland tumors: A blinded review by an international panel

BACKGROUND

Fine needle aspiration (FNA) is commonly used for the preoperative evaluation of salivary gland tumors. Tumor grade is a key factor influencing clinical management of salivary gland carcinomas (SGCs). To assess the ability to grade nonbasaloid SGCs in FNA specimens, an international panel of cytopathologists convened to review and score SGC cases.

METHODS

The study cohort included 61 cases of primary SGC from the pathology archives of 3 tertiary medical centers. Cases from 2005 to 2016 were selected, scanned, and digitized. Nineteen cytopathologists blinded to the histologic diagnosis reviewed the digitized cytology slides and graded them as low, high, or indeterminate. The panelists' results were then compared to the tumor grades based on histopathologic examination of the corresponding resection specimens.

RESULTS

All but 2 of the 19 (89.5%) expert panelists review more than 20 salivary gland FNAs per year; 16 (84.2%) of the panelists work at academic medical centers, and 13 (68.4%) have more than 10 years' experience. Participants had an overall accuracy of 89.4% in the grading of SGC cases, with 90.2% and 88.3% for low- and high-grade SGC, respectively. Acinic cell carcinoma and mucoepidermoid carcinoma had the highest degree of accuracy, while epithelial-myoepithelial carcinoma and salivary duct carcinoma had the lowest degree of accuracy. As expected, the intermediate-grade SGC cases showed the greatest variability (high-grade, 42.1%; low-grade, 37.5%, indeterminate, 20.4%).

CONCLUSION

This study confirms the high accuracy of cytomorphologic grading of primary SGC by FNA as low- or high-grade. However, caution should be exercised when a grade cannot be confidently assigned.

Analysis of the accuracy of actuation electronics in the laser interferometer space antenna pathfinder

The Laser Interferometer Space Antenna Pathfinder (LPF) main observable, labeled Δg, is the differential force per unit mass acting on the two test masses under free fall conditions after the contribution of all non-gravitational forces has been compensated. At low frequencies, the differential force is compensated by an applied electrostatic actuation force, which then must be subtracted from the measured acceleration to obtain Δg. Any inaccuracy in the actuation force contaminates the residual acceleration. This study investigates the accuracy of the electrostatic actuation system and its impact on the LPF main observable. It is shown that the inaccuracy is mainly caused by the rounding errors in the waveform processing and also by the random error caused by the analog to digital converter random noise in the control loop. Both errors are one order of magnitude smaller than the resolution of the commanded voltages. We developed a simulator based on the LPF design to compute the close-to-reality actuation voltages and, consequently, the resulting actuation forces. The simulator is applied during post-processing the LPF data.

LISA Pathfinder Performance Confirmed in an Open-Loop Configuration: Results from the Free-Fall Actuation Mode

We report on the results of the LISA Pathfinder (LPF) free-fall mode experiment, in which the control force needed to compensate the quasistatic differential force acting on two test masses is applied intermittently as a series of "impulse" forces lasting a few seconds and separated by roughly 350 s periods of true free fall. This represents an alternative to the normal LPF mode of operation in which this balancing force is applied continuously, with the advantage that the acceleration noise during free fall is measured in the absence of the actuation force, thus eliminating associated noise and force calibration errors. The differential acceleration noise measurement presented here with the free-fall mode agrees with noise measured with the continuous actuation scheme, representing an important and independent confirmation of the LPF result. An additional measurement with larger actuation forces also shows that the technique can be used to eliminate actuation noise when this is a dominant factor.

Beyond the Required LISA Free-Fall Performance: New LISA Pathfinder Results down to 20 μHz

In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20  μHz. The Letter presents the measured differential acceleration noise figure, which is at (1.74±0.05)  fm s^{-2}/sqrt[Hz] above 2 mHz and (6±1)×10  fm s^{-2}/sqrt[Hz] at 20  μHz, and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency.

Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results

We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2±0.1  fm s^{-2}/sqrt[Hz], or (0.54±0.01)×10^{-15}  g/sqrt[Hz], with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8±0.3)  fm/sqrt[Hz], about 2 orders of magnitude better than requirements. At f≤0.5  mHz we observe a low-frequency tail that stays below 12  fm s^{-2}/sqrt[Hz] down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.

Integrated clinical coding in urology – a novel way of working

Objectives:

The objective of this article is to report a completed cycle of audit of coding co-morbidities for bladder outlet surgery. We also present a novel way of working to achieve better accuracy in capturing admitted patient care data and coding in urology.

Materials and methods:

We undertook a retrospective case note and coding review of all bladder outlet surgeries performed in a single month. After initiating several measures to improve data recording and capture, we re-audited our results prospectively and analysed the results.

Results:

The initial accuracy of coding co-morbidities was 73%. This improved to 100% at re-audit. However, we found that procedure coding errors remained. We have devised a novel working model to improve all coding issues related to urology.

Conclusion:

It is possible to improve accuracy of coding by educating clinicians working alongside our integrated model of a team of a clinician with an interest in coding with coding and finance personnel.

Carbon fiber reinforced polymer dimensional stability investigations for use on the laser interferometer space antenna mission telescope

The laser interferometer space antenna (LISA) is a mission designed to detect low frequency gravitational waves. In order for LISA to succeed in its goal of direct measurement of gravitational waves, many subsystems must work together to measure the distance between proof masses on adjacent spacecraft. One such subsystem, the telescope, plays a critical role as it is the laser transmission and reception link between spacecraft. Not only must the material that makes up the telescope support structure be strong, stiff, and light, but it must have a dimensional stability of better than 1 pm Hz(-1/2) at 3 mHz and the distance between the primary and the secondary mirrors must change by less than 2.5 μm over the mission lifetime. Carbon fiber reinforced polymer is the current baseline material; however, it has not been tested to the pico meter level as required by the LISA mission. In this paper, we present dimensional stability results, outgassing effects occurring in the cavity and discuss its feasibility for use as the telescope spacer for the LISA spacecraft.

A double-blind, randomized controlled trial of the use of imiquimod cream for the treatment of anal canal high-grade anal intraepithelial neoplasia in HIV-positive MSM on HAART, with long-term follow-up data including the use of open-label imiquimod

OBJECTIVE

To determine whether imiquimod was more effective than placebo for the treatment of high-grade anal canal intraepithelial neoplasia (HG-ACIN).

DESIGN

Double-blind, randomized placebo-controlled clinical trial.

METHODS

Sixty-four HIV-positive patients were randomized to self-application of imiquimod cream or matched placebo into the anal canal three times a week for 4 months. Response was assessed by cytology, high-resolution anoscopy and biopsy 2 months after therapy. All patients who failed to resolve were offered treatment with open-label imiquimod for a further 4 months.

RESULTS

Fifty-three patients completed the study, of which 28 patients were on active drug and 25 patients on placebo. In the imiquimod group, four patients resolved and eight patients downgraded to low-grade squamous intraepithelial lesion (LSIL) with a median follow-up of 33 months. In the placebo group, one patient resolved. Imiquimod was significantly associated with a positive outcome (P = 0.003). Only one patient discontinued owing to side effects. Twenty-one patients entered a second open-label phase of treatment. Five of these patients cleared their anal canal intraepithelial neoplasia (ACIN) and four patients downgraded to LSIL. The overall mean duration of follow-up was 36 months. During this extended follow-up period, 61% have exhibited sustained absence of high-grade squamous intraepithelial lesion (HSIL).

CONCLUSION

This study demonstrates the effectiveness of imiquimod for the treatment of ACIN, and the benefit of prolonged or repeated treatments. This form of therapy is likely to be especially valuable for patients with widespread multifocal ACIN who are otherwise difficult to treat, and should be considered as an adjunct to ablative therapy.

Cognitive assessment of children at age 2(1/2) years after maternal fish oil supplementation in pregnancy: a randomised controlled trial

OBJECTIVE

To assess the effects of antenatal omega 3 long-chain polyunsaturated fatty acid (n-3 LC PUFA) on cognitive development in a cohort of children whose mothers received high-dose fish oil in pregnancy.

DESIGN

A double-blind randomised placebo-controlled trial.

SETTING

Perth, Western Australia, Australia.

PATIENTS

98 pregnant women received the supplementation from 20 weeks' gestation until delivery. Their infants (n = 72) were assessed at age 2(1/2) years.

INTERVENTIONS

Fish oil (2.2 g docosahexaenoic acid (DHA) and 1.1 g eicosapentaenoic acid (EPA)/day) or olive oil from 20 weeks' gestation until delivery.

OUTCOME MEASURES

Effects on infant growth and developmental quotients (Griffiths Mental Development Scales), receptive language (Peabody Picture Vocabulary Test) and behaviour (Child Behaviour Checklist).

RESULTS

Children in the fish oil-supplemented group (n = 33) attained a significantly higher score for eye and hand coordination (mean ((SD) score 114 (10.2)) than those in the placebo group (n = 39, mean score 108 (SD 11.3); p = 0.021, adjusted p = 0.008). Eye and hand coordination scores correlated with n-3 PUFA levels in cord blood erythrocytes (EPA: r = 0.320, p = 0.007; DHA: r = 0.308, p = 0.009) and inversely correlated with n-6 PUFA (arachidonic acid 20:4n-6: r = -0.331, p = 0.005). Growth measurements in the two groups were similar at age 2(1/2) years.

CONCLUSION

Maternal fish oil supplementation during pregnancy is safe for the fetus and infant, and may have potentially beneficial effects on the child's eye and hand coordination. Further studies are needed to determine the significance of this finding.

Transradial coronary intervention without pre-screening for a dual palmar blood supply

It is usual practice to determine the presence of collateral blood supply to the hand prior to radial artery cannulation. We propose that pre-screening for a dual palmar vascular supply is not necessary and the presence of a palpable radial pulse is sufficient to allow successful radial artery cannulation. We retrospectively analysed our interventional PTCA registry, including only patients who had a transradial procedure without being pre-screened with an Allen's test or plethysmography. We report our data including complications the day after the procedure and at 30 days, and provide an up to date discussion on the need to assess patients for a dual palmar blood supply prior to transradial intervention.

Characterization of gabaergic neurons within the human medial mamillary nucleus

The morphology, distribution and relative frequency of GABAergic neurons in the medial mamillary nucleus (MMN) of normal human individuals was studied using a glutamic acid decarboxylase (GAD) antiserum. GAD-immunoreactive (GAD-IR) neurons were found sparsely distributed throughout the MMN and most displayed a simple bipolar morphology. A small population of large diameter GAD-IR neurons was found in the white matter capsule adjacent to the ventral border of the MMN. Results of double-labeling experiments revealed no evidence of calretinin, parvalbumin or calbindin immunoreactivities co-localizing with GAD-IR neurons. GAD-IR neurons of the MMN had an average somal area of 138+/-41 microm2, compared with the average somal area of 384+/-137 microm2 for the population of MMN neurons as a whole. GAD-IR neurons had a tendency to cluster in groups of two (and occasionally three) and showed a distribution gradient across the MMN with higher densities being found near the insertion of the fornix, the origin of the mamillo-thalamic tract and toward the medial MMN border. Quantitative estimates of GAD-IR neuron frequency revealed the GAD-IR phenotype to constitute an average of 1.7% percent of the total neuron population within the human MMN. These findings suggest that inhibitory activity within the human MMN is regulated in part by a small population of intrinsic GABAergic interneurons.

A comparative study of amino acid consumption by rat islet cells and the clonal beta-cell line BRIN-BD11 - the functional significance of L-alanine

Evidence has been published that L -alanine may, under appropriate conditions, promote insulin secretion in normal rodent islets and various beta cell lines. Previous results utilising the clonal beta-cell line BRIN-BD11, demonstrated that alanine dramatically elevated insulin release by a mechanism requiring oxidative metabolism. We demonstrate in this paper that addition ofL -alanine had an insulinotropic effect in dispersed primary islet cells. Addition of D -glucose increasedL -alanine consumption in both BRIN-BD11 cells and primary islet cells.L -glutamine consumption in the BRIN-BD11 cell line and primary rat islets was also determined. The consumption rate was in line with that previously reported for cells of the immune system and other glutamine-utilising cells or tIssues. However,L -alanine consumption was at least an order of magnitude higher thanL -glutamine consumption. The metabolism ofL -alanine in the beta-cell may result in stimulation of insulin secretion via generation of metabolic stimulus secretion coupling factors such asL -glutamate.

Evidence for a sustained increase in clonal beta-cell basal intracellular Ca2+ levels after incubation in the presence of newly diagnosed Type-1 diabetic patient sera. Possible role in serum-induced inhibition of insulin secretion

We have previously reported that newly diagnosed Type-1 diabetic patient sera potently suppressed insulin secretion from a clonal rat pancreatic beta-cell line (BRIN BD11) but did not alter cell viability. Here, we report that apoptosis in BRIN BD11 cells incubated in various sera types (fetal calf serum (FCS), normal human serum and Type-1 diabetic patient) was virtually undetectable. Although low levels of necrosis were detected, these were not significantly different between cells incubated in sera from different sources. ATP levels were reduced by approximately 30% while nitrite production increased twofold from BRIN BD11 cells incubated for 24 h in the presence of Type-1 diabetic patient sera compared with normal human sera. Additionally, ATP levels were reduced by approximately 40% and DNA fragmentation increased by more than 20-fold in BRIN BD11 cells incubated in FCS in the presence of a pro-inflammatory cytokine cocktail (interleukin-1beta, tumour necrosis factor-alpha and interferon-gamma), compared with cells incubated in the absence of cytokines. Nitric oxide production from BRIN BD11 cells was markedly increased (up to 10-fold) irrespective of sera type when the cytokine cocktail was included in the incubation medium. Type-1 diabetic patient sera significantly (P<0.001) raised basal levels of intracellular free Ca(2+ )concentration ([Ca(2+)](i)) in BRIN BD11 cells after a 24-h incubation. The alteration in [Ca(2+)](i) concentration was complement dependent, as removal of the early complement components C1q and C3 resulted in a significant reduction (P<0.01) of sera-induced [Ca(2+)](i )changes. We propose that the mechanism of Type-1 diabetic patient sera-induced inhibition of insulin secretion from clonal beta-cells may involve complement-stimulated elevation of [Ca(2+)](i) which attenuates the nutrient-induced insulin secretory process possibly by desensitizing the cell to further changes in Ca(2+).

The introduction of a paediatric anaesthesia information leaflet: an audit of its impact on parental anxiety and satisfaction

BACKGROUND

A paediatric anaesthesia information leaflet was produced to address preoperative parental anxiety and to facilitate informed parental consent.

METHODS

An audit was undertaken to assess the impact of introducing the leaflet. This addressed the information needs and expectations of parents of children undergoing anaesthesia, parental satisfaction with information provision and parental preoperative anxiety.

RESULTS

The audit revealed that parents expect to be provided with information, although not necessarily in written form. However, the majority who received the information leaflet concluded that verbal information alone would not have been sufficient. The information leaflet was found to be accessible, informative and useful and those who received it reported greater satisfaction with information provision than a control group. Many parents perceived that it resulted in lower levels of preoperative anxiety

CONCLUSIONS

A decision was therefore undertaken that routine use of the leaflet would continue on all of the paediatric surgical wards. However, the study also indicated that leaflets should not replace verbal communication with nursing and medical staff, who remain important sources of information.

Quantitative analysis of glutamic acid decarboxylase-immunoreactive neurons in the anterior thalamus of the human brain

Local circuit neurons in the human anterior thalamus (AT) were identified on the basis of glutamic acid decarboxylase immunoreactivity (GAD-IR). GAD-IR neurons of the AT displayed small diameter somas with thin, sparsely-branching dendrites, consistent with the morphological characteristics of local circuit neurons found in the thalami of other mammals. Sampling techniques revealed an average of 42% of all neurons within the AT were GAD-IR, one of the highest reported percentages of local circuit neurons in the mammalian thalamus. The presence of high proportion of local circuit neurons in the AT may indicate the extent to which the Papez circuit has evolved within the human brain in comparison to other mammals.

Developmental outcomes of newborn encephalopathy in the term infant

Newborn encephalopathy is a clinically defined condition of abnormal neurological behaviours in the newborn period. Though most cases have their origin in the preconceptional and antepartum period, newborn encephalopathy represents a crucial link between intrapartum events and permanent neurological problems in the child. The birth prevalence of newborn encephalopathy ranges from 1.8 to 7.7 per 1000 term live births according to the definition used and the population to which it is applied. Few studies have investigated the outcomes of newborn encephalopathy other than for cases solely attributed to intrapartum hypoxia. These adverse outcomes range from death to cerebral palsy, intellectual disability, and less severe neurological disabilities such as learning and behavioural problems. Outcomes following newborn encephalopathy may vary from country to country with 9.1% of affected babies dying in the newborn period in Western Australia and 10.1% manifesting cerebral palsy by the age of two. These compare to a case fatality of 30.5% in Kathmandu and a cerebral palsy rate of 14.5% by one year of age. The study by Robertson et al which followed children with hypoxic ischaemic encephalopathy found an incidence of impairment of 16% among survivors assessed at 8 years with 42% requiring school resource room help or special classes. This review emphasises the great need for comprehensive clinical and educational assessment as these infants approach school entry to enable appropriate educational provisions to be made.

Gram-negative bacteria induce proinflammatory cytokine production by monocytes in the absence of lipopolysaccharide (LPS)

Tumour necrosis factor-alpha (TNF-alpha), IL-1alpha and IL-6 production by human monocytes in response to a clinical strain of the Gram-negative encapsulated bacteria Neisseria meningitidis and an isogenic lpxA- strain deficient in LPS was investigated. Wild-type N. meningitidis at concentrations between 105 and 108 organisms/ml and purified LPS induced proinflammatory cytokine production. High levels of these cytokines were also produced in response to the lpxA- strain at 107 and 108 organisms/ml. The specific LPS antagonist bactericidal/permeability-increasing protein (rBPI21) inhibited cytokine production induced by LPS and wild-type bacteria at 105 organisms/ml but not at higher concentrations, and not by LPS-deficient bacteria at any concentration. These data show that proinflammatory cytokine production by monocytes in response to N. meningitidis does not require the presence of LPS. Therapeutic strategies designed to block LPS alone may not therefore be sufficient for interrupting the inflammatory response in severe meningococcal disease.

Parvalbumin-immunoreactive neurons in the human anteroventral thalamic nucleus

We immunohistochemically characterised the expression of the calcium-binding protein parvalbumin in the normal human anteroventral thalamic nucleus (AVN). Two morphologically distinct neuronal populations were found to be parvalbumin-immunoreactive (PV-IR): a large population of lightly staining PV-IR neurons and a smaller population of intensely PV-IR neurons. This second type of neuron, which displayed many characteristics normally associated with GABAergic interneurons, has not previously been described in human thalamus. Thus, presumptive thalamic interneurons in the human brain can be further subtyped on the basis of immunoreactivity to parvalbumin. This may have implications for the understanding of thalamocortical function in the normal state and in dysfunctional conditions such as Wernicke-Korsakoff syndrome and schizophrenia.

Circulating platelet-neutrophil complexes represent a subpopulation of activated neutrophils primed for adhesion, phagocytosis and intracellular killing

Platelets play a prominent role in linking the processes of inflammation, haemostasis and thrombosis. Recent studies have shown that platelets form heterotypic aggregates with leucocytes via platelet CD62P and leucocyte beta2 integrins. These interactions have been observed in vitro in blood taken from healthy volunteers and in clinical conditions in which thrombosis and inflammation are prominent. This study investigated the properties of platelet-neutrophil complexes (PNCs) in anticoagulated whole blood. At rest, neutrophils in PNCs exhibit a significantly more activated adhesion molecule profile than free neutrophils with increased CD11b expression and activation (increased binding of the CD11b/CD18 'activation reporter' monoclonal antibody 24) and decreased CD62L expression. In addition, neutrophils in PNCs phagocytosed significantly more Neisseria meningitidis and produced more toxic oxygen metabolites than free neutrophils. Stimulation with the platelet agonist adenosine diphosphate (ADP) led to further increases in CD11b expression and activation, loss of CD62L as well as increased phagocytosis and toxic oxygen metabolite production throughout the whole neutrophil population. When these experiments were repeated with the CD62P blocking antibody G1 the effects were inhibited to a variable extent, dependent upon the parameter under investigation. These results indicate that both soluble and contact-dependent factors contribute to platelet-mediated neutrophil activation. Platelet neutrophil complexes represent a large subpopulation of neutrophils with a more activated adhesion molecule profile, and a greater capacity for phagocytosis and toxic oxygen metabolite production. This study provides further support for a role for PNCs in both health and disease.

The clinical course of patients with acute myocardial infarction who are unsuitable for thrombolytic therapy because of the presenting electrocardiogram. UK Heart Attack Study Investigators

OBJECTIVE

To examine the clinical characteristics and 30-day fatality rate among patients with electrocardiograms (ECGs) ineligible for fibrinolysis in a consecutive series in four general hospitals in the UK.

METHODS

We studied 2439 consecutive patients who were identified from regular ward visits, surveillance of results from hospital laboratories, and hospital discharge coding.

RESULTS

Thirty percent (732) of patients did not have ECGs eligible for fibrinolysis therapy, while indications were uncertain in 55 (2%). Within the ineligible group, patients presenting with ST depression (n = 294) had a higher 30-day fatality rate than those with ST elevation or left bundle branch block (26% versus 17%; P < 0.001); they represented 40% of the group ineligible for fibrinolysis therapy, or 12% of the total cohort. Thirty-day fatality rates in patients presenting with pathological Q waves and no diagnostic ST segment changes (n = 130), those with T wave changes but no other abnormality (n = 168) and those with a normal ECG (n = 128) were 10%, 5% and 3%, respectively. Despite their high fatality rate, fewer patients with ST depression were admitted to coronary care units than those with ECGs eligible for fibrinolysis therapy (61% versus 85%; P < 0.001) and 23% did not receive heparin. The coronary anatomy in a subset of patients with ST depression showed two- or three-vessel disease in 79% and left main stenosis in 9%. The rates of coronary revascularisation were low in all groups (< 10%).

CONCLUSION

Patients with ECGs ineligible for fibrinolysis therapy are a disparate group, with a high rate of fatality occurring in patients who present with ST depression. The high prevalence of multiple vessel coronary disease in patients with ST depression suggests that a more active management strategy is required.

The Saccharomyces cerevisiae CCH1 gene is involved in calcium influx and mating

The yeast Saccharomyces cerevisiae gene CCH1 (ORF YGR217w) shows high homology with animal calcium channel alpha1-subunit genes. Knock-out mutants were constructed of Cch1 and of Mid1 which is known to mediate Ca2+ influx in response to the alpha-mating pheromone. Cch1 is involved in calcium influx and the late stage of the mating process. The cch1 mutant sensitivity against the alpha-mating pheromone can be reduced by the addition of extra calcium. The product of this gene is likely to interact with the MID1 gene product in Ca influx or its control.

A reporter gene assay for fungal sterol biosynthesis inhibitors

Acetoacetyl-CoA thiolase (ACoAT) catalyses the condensation of two acetyl-CoA molecules, the first step in the sterol biosynthetic pathway. We constructed a yeast strain containing a fusion of the promoter of the Saccharomyces cerevisiae ACoAT gene to a reporter gene (Escherichia coli beta-galactosidase). Reporter gene activity in this strain can be induced by a variety of inhibitors of sterol biosynthesis. These results suggest that the ACoAT gene is feedback regulated at the transcriptional level by products of the sterol biosynthetic pathway. The reporter gene approach described here may be used to screen chemical collections for compounds which inhibit fungal sterol biosynthesis.

Molecular biological investigations into the role of the NMDA receptor in the pathophysiology of schizophrenia

OBJECTIVE

There is increasing acceptance that schizophrenia is associated with a generalised disorder in cortical neurodevelopment. The aim of this paper is to review the evidence that this disorder may be accounted for by abnormalities in mechanisms mediated by the main family of excitatory neuroreceptors in cortical brain systems, the N-methyl-D-aspartate (NMDA) glutamatergic receptors.

METHOD

The neurobiological evidence is presented for an abnormality in cortical development related to synaptic pathology in schizophrenia. The unique functions of the NMDA receptor in information processing are described, especially its role in learning and memory, and in neural plasticity and brain development. It is argued that the cellular and molecular mechanisms which underlie learning and memory also govern normal brain development. Studies examining abnormalities in glutamatergic transmission in schizophrenia are reviewed.

RESULTS

There is a substantial literature in support of the possibility that NMDA receptor abnormalities may be involved in the neurodevelopmental predisposition to schizophrenia, as well as in symptom production.

CONCLUSIONS

Research to determine the role of the NMDA receptor in the pathophysiology of schizophrenia is warranted and now feasible. To be successful, this research will require the application of molecular biology techniques to postmortem brain tissue studies, in addition to traditional histochemical approaches.

Utilising molecular biological and histopathological techniques to study the dopaminergic system in patients with melancholia

OBJECTIVE

To describe the rationale for investigating the dopaminergic system in patients with melancholia by applying molecular biological (notably, in situ hybridisation) and histopathological techniques in postmortem brain tissue.

METHOD

Relevant advances in the functional neuroanatomy of frontostriatal circuits, as well as insights from clinical neuroimaging studies in primary and secondary depressive disorders, are presented. These are integrated with developments in the pharmacological and molecular characteristics of dopamine receptor subtypes and recognition of their selective anatomical distribution.

RESULTS

Converging data from the basic and clinical neurosciences suggest that the pathophysiology of depressive disorders characterised by psychomotor phenomena, such as melancholia, may involve dysregulation of dopaminergic mechanisms within complex frontostriatal circuits.

CONCLUSIONS

The key feature of in situ hybridisation is its capacity to test for variations in the functional components of designated biochemical systems within highly specific anatomical regions. We utilise this approach, in combination with relevant histopathological techniques, to test the structural and functional integrity of the dopaminergic system within key fronto-striatal circuits in patients who had exhibited psychomotor phenomena. The same approach can also be used to study the integrity of other relevant biochemical systems, such as the serotoninergic and noradrenergic systems, in patients with other mood disorders.

Molecular biology and the major psychoses

OBJECTIVE

To highlight the potential role of molecular biological studies in examining the expression of genes of interest in brain tissue to elucidate the pathophysiological basis of the major psychoses.

METHOD

To review the principles underlying the available techniques for expression studies.

RESULTS

Detection of messenger RNA by in situ hybridisation and quantitation by Northern analysis are powerful tools to detect abnormalities in gene expression in brain tissue.

CONCLUSION

The availability of simple techniques to examine the expression of RNA and protein products of individual genes, including examination at the level of individual cells, offers a clear opportunity to define the molecular basis of the major psychoses.

The changing profile of undergraduate dental students at the University of Otago 1992-1994

Incoming students to the School of Dentistry, University of Otago, were surveyed in 1992, 1993, and 1994. Since 1992 there has been a marked trend for the students to originate from an overseas culture, to have more wealthy parents who support their education, and an increase in the numbers who expect to practice overseas upon graduation. This has implications for workforce planning in New Zealand and raises issues relating to equality of access to tertiary education.