Anatomical integration and rich-club connectivity in euthymic bipolar disorder.

BACKGROUND: Although repeatedly associated with white matter microstructural alterations, bipolar disorder (BD) has been relatively unexplored using complex network analysis. This method combines structural and diffusion magnetic resonance imaging (MRI) to model the brain as a network and evaluate its topological properties. A group of highly interconnected high-density structures, termed the 'rich-club', represents an important network for integration of brain functioning. This study aimed to assess structural and rich-club connectivity properties in BD through graph theory analyses. METHOD: We obtained structural and diffusion MRI scans from 42 euthymic patients with BD type I and 43 age- and gender-matched healthy volunteers. Weighted fractional anisotropy connections mapped between cortical and subcortical structures defined the neuroanatomical networks. Next, we examined between-group differences in features of graph properties and sub-networks. RESULTS: Patients exhibited significantly reduced clustering coefficient and global efficiency, compared with controls globally and regionally in frontal and occipital regions. Additionally, patients displayed weaker sub-network connectivity in distributed regions. Rich-club analysis revealed subtly reduced density in patients, which did not withstand multiple comparison correction. However, hub identification in most participants indicated differentially affected rich-club membership in the BD group, with two hubs absent when compared with controls, namely the superior frontal gyrus and thalamus. CONCLUSIONS: This graph theory analysis presents a thorough investigation of topological features of connectivity in euthymic BD. Abnormalities of global and local measures and network components provide further neuroanatomically specific evidence for distributed dysconnectivity as a trait feature of BD.

Addressing the gap for racially diverse research involvement: The King's Model for minority ethnic research participant recruitment.

Objectives: Ethnic minorities (EM) are still underrepresented in research recruitment. Despite wide literature outlining the barriers, enablers and recommendations for driving inclusion and diversity in research, there is still little evidence for successful diversity in research participation, which has a direct impact on the quality of care provided to ethnically diverse individuals. A new, comprehensive approach to recruitment strategies is therefore necessary. Study design: service improvement initiative. Methods: In the light of the Covid-19 pandemic and the key public health need to address the disparity in care provided to non-white populations, we used a novel, comprehensive approach (The King's Model) comprising of local and community actions to promote inclusive research recruitment. We then compared rates of diverse recruitment in studies where the novel approach, was applied to studies which had been closed to recruitment at the time of analysis and where ethnicity data was available. Results: Our results demonstrate that following the introduction of the King's Model for diverse recruitment, commercial interventional study diverse recruitment increased from 6.4% to 16.1%, and for non-commercial studies, from 30.2% to 41.0% and 59.2% in the selected studies. Conclusions: King's Model is potentially a useful tool in enhancing non-Caucasian recruitment to clinical research. Enriched by additional recommendations based on our experiences during the Covid-19 research recruitment drive, we propose the King's Model is used to support ethnically diverse research recruitment. Further evidence is needed to replicate our findings, although this preliminary evidence provides granular details necessary to address the key unmet need of validating clinical research outcomes in non-white populations.

Intensive care unit experience of haemopoietic stem cell transplant patients.

BACKGROUND: Previous research at our institution (1988-1998) established an intensive care unit (ICU) and hospital mortality between 70% and 80% in haemopoietic stem cell transplant (HSCT) patients requiring ICU admission. AIMS: This study explored mortality in a more contemporary cohort while comparing outcomes to published literature and our previous experience. METHODS: Retrospective chart review of HSCT patients admitted to ICU between December 1998 and June 2008. RESULTS: Of 146 admissions, 53% were male, with a mean age of 44 years, an Acute Physiologic and Chronic Health Evaluation II score of 28 and Sepsis Organ Failure Assessment score of 11. Fifty-six per cent had graft versus host disease (GVHD), with respiratory failure (67%) being the most common admission diagnosis. All but one received mechanical ventilation. The ICU and hospital mortality were 42% (72% 1988-1998 cohort) and 64% (82% 1998-1998 cohort) respectively. The 6- and 12-month survivals were 29% and 24% respectively for the 1998-2008 cohort. Dying in ICU was independently predicted by fungal infection (P= 0.02) and early onset of organ failure (P < 0.001), while GVHD (P= 0.04) predicted survival. Mortality at 12 months was independently predicted by the acute physiology score (P= 0.002), increasing number of organ failures (P= 0.001), and cytomegalovirus positive serology (P= 0.005), while blood stream infection (P= 0.003), an antibiotic change on admission to the ICU (P= 0.007) and a diagnosis of non-Hodgkin lymphoma (P= 0.02) predicted survival. CONCLUSION: Our study found that acute admission of HSCT patients to the ICU is associated with improved survival compared to our previous experience, with organ failure progression a strong predictor of ICU outcome, and specific disease characteristics contributing to long-term survival.

Analysis of the aetiology of epilepsy in 3,216 adult patients attending a tertiary referral center enabled by an electronic patient record.

PURPOSE: The aim of this study was to review the causes of the epilepsies in our institution, an adult tertiary referral center for neurology and neurosurgery in Dublin, Ireland. Data was obtained from a bespoke epilepsy electronic patient record (EPR). METHODS: Predetermined search parameters of well-established broad categories of epilepsy aetiology were used to identify patients with a diagnosis of epilepsy attending Beaumont Hospital, Dublin. There were 3216 patients that met the inclusion criteria for this study. We included living patients with epilepsy attending our institution. We then excluded patients with a diagnosis of pure non-epileptic attack disorder and patients found to have idiopathic generalised epilepsy (IGE) (n = 382) from our final cohort. We excluded IGE due to the complex polygenic basis underlying this patient group. RESULTS: An aetiology was identified in 54.3 % (n = 1747) of the total number of patients studied. Of the symptomatic epilepsies, 41.08 % (n = 1321) were acquired and 13.3 % (n = 426) were predominantly of genetic or developmental aetiology. The most common causes of the acquired epilepsies were hippocampal sclerosis (n = 380; 28.75 %), cerebral tumor (n = 279; 21.06 %), traumatic brain injury (n = 248; 18.77 %), stroke and cerebrovascular disease (n = 151; 11.43 %) and perinatal causes (n = 138; 10.45 %). The leading causes in the genetic / developmental category included cavernous haemangiomas (n = 62, 22.22 %), arteriovenous malformations (n = 59; 21.15 %) and cortical dysplasia (n = 55; 19.71 %). The aetiology of a patient's epilepsy was undetermined in 45.68 % (n = 1469) of individuals. CONCLUSION: This study emphasizes the clinical utility of the ILAE's 2017 revised classification of the epilepsies and highlights the evolving dynamic nature of attributing causality in epilepsy. This is the largest single centre analysis of the aetiology of the epilepsies described in the literature. It is also the first large scale study examining aetiology utilising a bespoke electronic patient record in epilepsy.

Optical linewidth of a passively mode-locked semiconductor laser.

We measured the optical linewidths of a passively mode-locked quantum dot laser and show that, in agreement with theoretical predictions, the modal linewidth exhibits a parabolic dependence with the mode optical frequency. The minimum linewidth follows a Schawlow-Townes behavior with a rebroadening at high power. In addition, the slope of the parabola is proportional to the RF linewidth of the laser and can therefore provide a direct measurement of the timing jitter. Such a measurement could be easily applied to mode-locked semiconductor lasers with a fast repetition rate where the RF linewidth cannot be directly measured.

Point of care measurement of plasma creatinine in critically ill patients with acute kidney injury.

We report the utility of an enzymatic point of care system for estimation of plasma creatinine concentration in critically ill patients with acute kidney injury. Multiple measurements were obtained from a heterogenous population admitted to a multi-disciplinary intensive care unit. The acute kidney injury network guidelines were used to identify and stratify patients based on the creatinine concentration. Central laboratory values were used as comparators to assess the precision and bias of the system. Overall, point of care measurements correlated well with central pathology results (R(2) = 0.991, p < 0.001), although there tended to be a small negative bias in patients with acute kidney injury (3 micromol x l(-1)). The accuracy of point of care measurement is within clinically acceptable limits and given the much shorter turn around time can be used to identify and monitor patients with acute kidney injury in the critical care environment.

Acquired hypernatraemia is an independent predictor of mortality in critically ill patients.

This study reports the incidence and associated mortality of acquired hypernatraemia (Na > 150 mmol x l(-1)) in a general medical/surgical intensive care unit. Patients admitted over a 5-year period with normal sodium values were eligible for inclusion; exclusions were made for burn/neurosurgical diagnoses and for hypertonic saline therapy. From 3475 admissions (3317 patients), 266 (7.7%) episodes of hypernatraemia were observed. Hospital mortality was 33.5% in the hypernatraemic group and 7.7% in the normonatraemic group (p < 0.001). Acquired hypernatraemia was an independent risk factor for in-hospital mortality (OR 1.97, 95% CI 1.37-2.82, p < 0.001). Intermediate sodium levels (145-150 mmol x l(-1)) were associated with increased mortality (OR 1.42, 95% CI 1.02-1.98). Uncorrected sodium at discharge (p = 0.001) and peak sodium (p = 0.001) were better predictors of mortality than time to onset (p = 0.71) and duration of hypernatraemia (p = 1.0). Hypernatraemia avoidance is justified, but determinants of hypernatraemia and benefits of targeted treatment strategies require further elucidation.

Automatic implantable cardioverter-defibrillator: is early implantation cost-effective?

The evaluation of survivors of sudden cardiac death with serial electrophysiologic studies involves a lengthy and expensive hospitalization, especially when an automatic implantable cardioverter-defibrillator is ultimately necessary. The cost efficacy of this conventional approach was therefore compared with direct implantation of a cardioverter-defibrillator after the first electrophysiologic study. Thirty-two survivors of sudden death who had inducible ventricular tachycardia during their initial electrophysiologic study underwent serial drug trials. At discharge 12 (37%) were taking an antiarrhythmic drug found to prevent induction of ventricular tachycardia and 20 underwent cardioverter-defibrillator implantation after serial drug trials proved ineffective. The average length of hospitalization for this group that had undergone serial drug testing was 20.2 +/- 9.3 days at an average cost of $48,900 +/- $31,600. Seven survivors of sudden death had no inducible ventricular tachycardia during their initial electrophysiologic study and underwent direct cardioverter-defibrillator implantation. Their average length of hospitalization was 12.6 +/- 6.2 days at an average cost of $40,400 +/- $8,300. It is concluded that automatic implantable cardioverter-defibrillator implantation as an early intervention is not more costly and indeed may be cost-effective compared with therapy guided by serial electrophysiologic testing. As antitachycardia devices become more versatile, long lived and easier to implant, earlier implantation is likely to compare even more favorably with drug therapy.

Automated NOESY interpretation with ambiguous distance restraints: the refined NMR solution structure of the pleckstrin homology domain from beta-spectrin.

We have used a novel, largely automated, calculation method to refine the NMR solution structure of the pleckstrin homology domain of beta-spectrin. The method is called ARIA for Ambiguous Restraints for Iterative Assignment. The starting point for ARIA is an almost complete assignment of the proton chemical shifts, and a list of partially assigned NOEs, mostly sequential and secondary structure NOEs. The restraint list is then augmented by automatically interpreting peak lists generated by automated peak-picking. The central task of ARIA is the assignment of ambiguous NOEs during the structure calculation using a combination of ambiguous distance restraints and an iterative assignment strategy. In addition, ARIA calibrates ambiguous NOEs to derive distance restraints, merges overlapping data sets to remove duplicate information, and uses empirical rules to identify erroneous peaks. While the distance restraints for the structure calculations were exclusively extracted from homonuclear 2D experiments, ARIA is especially suited for the analysis of multidimensional spectra. Applied to the pleckstrin homology domain, ARIA generated structures of good quality, and of sufficiently high accuracy to solve the X-ray crystal structure of the same domain by molecular replacement. The comparison of the free NMR solution structure to the X-ray structure, which is complexed to D-myo-inositol-1,4,5-triphosphate, shows that the ligand primarily induces a disorder-order transition in the binding loops, which are disordered in the NMR ensemble but well ordered in the crystal. The structural core of the protein is unaffected, as evidenced by a backbone root-mean-square difference between the average NMR coordinates and the X-ray crystal structure for the secondary structure elements of less than 0.6 A.

Adaptation of protein surfaces to subcellular location.

In vivo, proteins occur in widely different physio-chemical environments, and, from in vitro studies, we know that protein structure can be very sensitive to environment. However, theoretical studies of protein structure have tended to ignore this complexity. In this paper, we have approached this problem by grouping proteins by their subcellular location and looking at structural properties that are characteristic to each location. We hypothesize that, throughout evolution, each subcellular location has maintained a characteristic physio-chemical environment, and that proteins in each location have adapted to these environments. If so, we would expect that protein structures from different locations will show characteristic differences, particularly at the surface, which is directly exposed to the environment. To test this hypothesis, we have examined all eukaryotic proteins with known three-dimensional structure and for which the subcellular location is known to be either nuclear, cytoplasmic, or extracellular. In agreement with previous studies, we find that the total amino acid composition carries a signal that identifies the subcellular location. This signal was due almost entirely to the surface residues. The surface residue signal was often strong enough to accurately predict subcellular location, given only a knowledge of which residues are at the protein surface. The results suggest how the accuracy of prediction of location from sequence can be improved. We concluded that protein surfaces show adaptation to their subcellular location. The nature of these adaptations suggests several principles that proteins may have used in adapting to particular physio-chemical environments; these principles may be useful for protein design.

Comparison of ARM and HEAT protein repeats.

ARM and HEAT motifs are tandemly repeated sequences of approximately 50 amino acid residues that occur in a wide variety of eukaryotic proteins. An exhaustive search of sequence databases detected new family members and revealed that at least 1 in 500 eukaryotic protein sequences contain such repeats. It also rendered the similarity between ARM and HEAT repeats, believed to be evolutionarily related, readily apparent. All the proteins identified in the database searches could be clustered by sequence similarity into four groups: canonical ARM-repeat proteins and three groups of the more divergent HEAT-repeat proteins. This allowed us to build improved sequence profiles for the automatic detection of repeat motifs. Inspection of these profiles indicated that the individual repeat motifs of all four classes share a common set of seven highly conserved hydrophobic residues, which in proteins of known three-dimensional structure are buried within or between repeats. However, the motifs differ at several specific residue positions, suggesting important structural or functional differences among the classes. Our results illustrate that ARM and HEAT-repeat proteins, while having a common phylogenetic origin, have since diverged significantly. We discuss evolutionary scenarios that could account for the great diversity of repeats observed.

Applying neuroimaging to detect neuroanatomical dysconnectivity in psychosis.

This editorial discusses the application of a novel brain imaging analysis technique in the assessment of neuroanatomical dysconnectivity in psychotic illnesses. There has long been a clinical interest in psychosis as a disconnection syndrome. In recent years graph theory metrics have been applied to functional and structural imaging datasets to derive measures of brain connectivity, which represent the efficiency of brain networks. These metrics can be derived from structural neuroimaging datasets acquired using diffusion imaging whereby cortical structures are parcellated into nodes and white matter tracts represent edges connecting these nodes. Furthermore neuroanatomical measures of connectivity may be decoupled from measures of physiological connectivity as assessed using functional imaging, underpinning the need for multi-modal imaging approaches to probe brain networks. Studies to date have reported a number of structural brain connectivity abnormalities associated with schizophrenia that carry potential as illness biomarkers. Structural connectivity abnormalities have also been reported in well patients with bipolar disorder and in unaffected relatives of patients with schizophrenia. Such connectivity metrics may represent clinically relevant biomarkers in studies employing a longitudinal design of illness course in psychosis.

Unstable angina: natural history and determinants of prognosis.

One hundred one patients with unstable angina were treated conservatively without the routine use of beta receptor blocking agents, calcium antagonist drugs, anticoagulant agents or nitrates. Only two patients underwent arteriography and coronary arterial bypass surgery during hospitalization and one patient during the 1st year of follow-up study. The 28 day mortality rate was 4 percent and the total 1 year cardiac mortality rate 10 percent. Two patients died from carcinoma. The incidence rate of nonfatal myocardial infarction was 9 percent during the first 28 days and a further 3 percent for the 1st year. These results compare favorably with the immediate and 1 year prognosis reported from other studies using different treatment procedures, including modern intensive drug treatment and coronary arterial bypass surgery. Various factors studied during the acute stage of unstable angina were assessed in an effort to predict the immediate and long-term outcome. Only persistence of pain after admission to the hospital was found a significant indicator of an adverse prognosis. Modern medical treatment of unstable angina with beta receptor blocking agents, calcium antagonist drugs, anticoagulant agents, nitrates and antiarrhythmic agents is critically examined. The paucity of proper randomized controlled studies confirming the value of medication is underlined. There is little evidence to show that aggressive or intensive medical or surgical treatment is superior to a conservative approach to management in the coronary care unit. This approach includes bed rest until the pain has resolved, symptomatic drug treatment only, the minimal use of invasive investigations and careful risk factor intervention.

Effect of milrinone in human platelet shape change, aggregation and thromboxane A2 synthesis: an in vitro study.

Milrinone (MIL; a cAMP-specific phosphodiesterase type-III inhibitor), added in vitro to achieve concentrations below the therapeutic levels, inhibited agonist-induced platelet shape change (PSC). Arachidonic acid (AA)-induced PSC was significantly more inhibited by a combination of MIL and indomethacin (INDO; a cyclooxygenase inhibitor) than by either alone. PSC induced by 5-hydroxytryptamine was inhibited by MIL but not by INDO; and this effect of MIL was not augmented by INDO. Whole blood-platelet aggregation (WB-PA) and platelet-rich plasma aggregation induced by potent stimulators of thromboxane A2 (TXA2) synthesis such as AA and calcium ionophore and by less potent agonists (e.g. ADP and U46619) were inhibited by MIL at or near therapeutic concentrations. WB-PA induced by collagen was significantly more inhibited by the MIL and INDO combination than by either of these agents alone whereas with ADP-induced WB-PA no additional effect could be shown when both MIL and INDO were co-incubated. MIL and similar types of drugs may be of benefit in conditions associated with platelet hyperactivity and some of these effects may be enhanced by cyclooxygenase inhibitors.

Uninfected random walkers in one dimension.

We consider a system of unbiased diffusing walkers (A(Phi)<-->(Phi)A) in one dimension with random initial conditions. We investigate numerically the relation between the fraction of walkers U(t) which have never encountered another walker up to time t, calling such walkers "uninfected" and the fraction of sites P(t) which have never been visited by a diffusing particle. We extend our study to include the A+B--> Phi diffusion-limited reaction in one dimension, with equal initial densities of A and B particles distributed homogeneously at t=0. We find U(t) approximately [P(t)]gamma, with gamma approximately 1.39, in both models, though there is evidence that a smaller value of gamma is required for t-->infinity.

Fraction of uninfected walkers in the one-dimensional Potts model.

The dynamics of the one-dimensional q-state Potts model, in the zero-temperature limit, can be formulated through the motion of random walkers which either annihilate (A+A-->Phi) or coalesce (A+A-->A) with a q-dependent probability. We consider all of the walkers in this model to be mutually infectious. Whenever two walkers meet, they experience mutual contamination. Walkers which avoid an encounter with another random walker up to time t remain uninfected. The fraction of uninfected walkers is known to obey a power-law decay U(t) approximately t(-phi(q)), with a nontrivial exponent phi(q) [C. Monthus, Phys. Rev. E 54, 4844 (1996); S. N. Majumdar and S. J. Cornell, ibid. 57, 3757 (1998)]. We probe the numerical values of phi(q) to a higher degree of accuracy than previous simulations and relate the exponent phi(q) to the persistence exponent theta(q) [B. Derrida, V. Hakim, and V. Pasquier, Phys. Rev. Lett. 75, 751 (1995)], through the relation phi(q)=gamma(q)theta(q) where gamma is an exponent introduced in [S. J. O'Donoghue and A. J. Bray, preceding paper, Phys. Rev. E 65, 051113 (2002)]. Our study is extended to include the coupled diffusion-limited reaction A+A-->B, B+B-->A in one dimension with equal initial densities of A and B particles. We find that the density of walkers decays in this model as rho(t) approximately t(-1/2). The fraction of sites unvisited by either an A or a B particle is found to obey a power law, P(t) approximately t(-theta) with theta approximately 1.33. We discuss these exponents within the context of the q-state Potts model and present numerical evidence that the fraction of walkers which remain uninfected decays as U(t) approximately t(-phi), where phi approximately 1.13 when infection occurs between like particles only, and phi approximately 1.93 when we also include cross-species contamination. We find that the relation between phi and theta in this model can also be characterized by an exponent gamma, where similarly, phi=gamma(theta).

Persistence in the one-dimensional A+B--> Ø reaction-diffusion model.

The persistence properties of a set of random walkers obeying the A+B--> Ø reaction, with equal initial density of particles and homogeneous initial conditions, is studied using two definitions of persistence. The probability P(t) that an annihilation process has not occurred at a given site has the asymptotic form P(t) approximately const+t(-straight theta), where straight theta is the persistence exponent (type I persistence). We argue that, for a density of particles rho>>1, this nontrivial exponent is identical to that governing the persistence properties of the one-dimensional diffusion equation, partial differential(t)straight phi= partial differential(xx)straight phi, where straight theta approximately 0.1207 [S. N. Majumdar, C. Sire, A. J. Bray, and S. J. Cornell, Phys. Rev. Lett. 77, 2867 (1996)]. In the case of an initial low density, rho(0)<<1, we find straight theta approximately 1/4 asymptotically. The probability that a site remains unvisited by any random walker (type II persistence) is also investigated and found to decay with a stretched exponential form, P(t) approximately exp(-constxrho(1/2)(0)t(1/4)), provided rho(0)<<1. A heuristic argument for this behavior, based on an exactly solvable toy model, is presented.

Measurement of platelet volume using a channelyzer: assessment of the effect of agonists and antagonists.

Platelets undergo morphological changes prior to aggregating. This phenomenon is known as the platelet shape change (PSC) and is usually accompanied by at increase in median platelet volume (MePV). We evaluated MePV changes in human platelet rich plasma (PRP) using a high resolution pulse-height analyser ("channelyzer"). Increases in MePV were induced by the addition of low concentrations of known aggregating agents. These agonists showed different patterns in terms of potency, duration and reversibility.

Intratester and intertester reliability and criterion validity of the parallelogram and universal goniometers for active knee flexion in healthy subjects.

BACKGROUND AND PURPOSE: A new parallelogram goniometer was designed by the Rehabilitation Centre of the Royal Ottawa Health Care Group in 1983. The advantage of using such a goniometer is that the clinician is not required to estimate the joint axis of rotation when taking a measurement. The parallelogram goniometer has obtained a good intratester and intertester reliability when measuring active range of motion of hip abduction on eight individuals with hip pathologies. However, the validity of the parallelogram goniometer has not been examined. The purposes of this study were to examine the intratester and intertester reliability and the criterion validity of the parallelogram and universal goniometers for active knee flexion on healthy individuals. SUBJECTS: Sixty healthy university students (44 females and 16 males; mean age of 20.6 yrs.) participated to this study. METHODS: Measurements with the universal and parallelogram goniometers were taken in two different positions, the smaller and larger angles of active knee flexion. All measurements were taken by two trained testers. A radiograph was taken in both positions to serve as the 'gold standard'. The sequence of the measurements and radiographs were randomly selected. The intra and intertester reliability of both goniometers were established by calculating the intraclass correlation coefficients (ICCs) using the repeated-measures ANOVA. The criterion validity was examined by calculating Pearson product-moment correlation coefficients (tau) between each goniometric and radiologic measurements. A 0.05 level of significance was chosen for each statistical test. RESULTS: Intratester reliability ranged from good to excellent for the small angles (ICC = 0.85 and 0.87) and the large angles (ICC = 0.91 and 0.96) when using the parallelogram goniometer. Intertester reliability was fair for the small angles of flexion (ICC = 0.43 to 0.52) and good to excellent for the large angles of flexion (ICC = 0.82 to 0.88). The parallelogram goniometer was found to have greater validity when measuring the large angles of knee flexion (r = 0.73 and 0.77) compared to the small angles of knee flexion (r = 0.33 and 0.41). Similar results of reliability and validity were obtained with the universal goniometer. CONCLUSION: The results of this study have clinical importance. The use of the parallelogram goniometer was found to be as reliable and valid as the universal goniometer when measuring active knee flexion. However, the parallelogram goniometer offered clinicians the advantages of obtaining precise angular measurements with fewer adjustments, and a faster application technique. Further studies on the parallelogram goniometer are necessary among individuals presenting with altered range of motion at different joints.

The otolaryngology, head and neck training appraisal questionnaire: a national general practice perspective.

BACKGROUND: Diseases of the Ear, Nose and Throat (ENT) make up a considerable proportion of the everyday workload of general practitioners (GPs). It is recognized that ENT makes up a very small part of the undergraduate curriculum, but some post-graduate training schemes are now offering placements in Otolaryngology. AIM: The aim of the study was to examine a perceived knowledge 'gap' of GPs in the area of Otolaryngology. METHOD: A postal questionnaire was sent to 1,000 GPs distributed evenly throughout the country. RESULTS: There was a 47.3 % response rate; 72 % of GPs felt that they would see at least three or more children with a relevant ENT problem each day. Almost 70 % of GPs had less than a month exposure to ENT in medical school and 84 % of GPs felt that further emphasis was required at the undergraduate level. Twenty-one per cent of GPs surveyed had spent some time in Postgraduate ENT training. Ninety-one per cent of GPs agreed that further emphasis on ENT training was required at the Postgraduate level. CONCLUSION: General Practitioners feel that increased importance should be placed on the study of Otolaryngology at both undergraduate and Postgraduate level.