Emergency drug use in a pandemic: Harsh lessons from COVID-19

The scientific and clinical communities have both experienced several harsh lessons on clinical care management and drug development during the COVID-19 pandemic. Here, we discuss several key lessons learned and describe a framework within which our two communities can work together and invest in to improve future pandemic responses.

Abstract P108: Impact of the Covid-19 Pandemic on Hyperacute Stroke Treatment: Experience From a Comprehensive Stroke Centre in Singapore

Background: The Coronavirus disease 2019 (COVID-19) pandemic is rapidly evolving and affecting healthcare systems across the world. Singapore has escalated its alert level to Disease Outbreak Response System Condition (DORSCON) Orange, signifying severe disease with community spread.

Objectives: We aimed to study the overall volume of AIS cases and the delivery of hyperacute stroke services during DORSCON Orange.

Methods: This was a single-centre, observational cohort study performed at a comprehensive stroke centre responsible for AIS cases in the western region of Singapore, as well as providing care for COVID-19 patients. All AIS patients reviewed as an acute stroke activation in the Emergency Department (ED) from November 2019 to April 2020 were included. System processes timings, treatment and clinical outcome variables were collected.

Results: We studied 350 AIS activation patients admitted through the ED, 206 (58.9%) pre- and 144 during DORSCON Orange. Across the study period, number of stroke activations showed significant decline (p =0.004, 95% CI 6.513 - -2.287), as the number of COVID-19 cases increased exponentially, whilst proportion of activations receiving acute recanalization therapy remained stable ( p = 0.519, 95% CI -1.605 - 2.702). Amongst AIS patients that received acute recanalization therapy, early neurological outcomes in terms of change in median NIHSS at 24 hours (-4 versus -4, p = 0.685) were largely similar between the pre- and during DORSCON orange periods.

Conclusions: The number of stroke activations decreased while the proportion receiving acute recanalization therapy remained stable in the current COVID-19 pandemic in Singapore.

Coronavirus 2019 Silver Linings

A heightened state of alert due to the Coronavirus Disease 2019 (COVID-19) outbreak was declared by the Singapore Ministry of Health on February 7, 2020. Within the hospital, team reorganizations, workflow revisions, and physical segregation caused anxiety among healthcare workers (HCWs). Fear of the unknown and emotional and physical fatigue started to take their toll on HCWs. We share our learning journey over the first 8 weeks of COVID-19: the importance of acknowledging fears and questions, and transforming them to collective knowledge; the role of empathic, hands-on leadership that brings camaraderie and calms scepticism; the importance of validating efforts and acknowledging hardship; and, most importantly, the security that comes from camaraderie, breaking down hierarchical barriers, and motivating each other to keep on going.

Responding to COVID-19: how an academic infectious diseases division mobilized in Singapore

BACKGROUND

On January 30, COVID-19 was declared a Public Health Emergency of International Concern-a week after Singapore's first imported case and 5 days before local transmission. The National University Hospital (NUH) is Singapore's third largest hospital with 1200 beds, heavy clinical workloads, and major roles in research and teaching.

MAIN BODY

With memories of SARS still vivid, there was an urgent requirement for the NUH Division of Infectious Diseases to adapt-undergoing major reorganization to face rapidly changing priorities while ensuring usual essential services and standards. Leveraging on individual strengths, our division mobilized to meet the demands of COVID-19 while engaging in high-level coordination, strategy, and advocacy. We present our experience of the 60 days since the nation's first case. During this time, our hospital has managed 3030 suspect cases, including 1300 inpatients, 37 confirmed cases, and overseen 4384 samples tested for COVID-19.

CONCLUSION

Complex hospital adaptations were supported by an unprecedented number of workflows and coordination channels essential to safe and effective operations. The actions we describe, aligned with international recommendations and emerging evidence-based best practices, may serve as a framework for other divisions and institutions facing the spread of COVID-19 globally.

Measurement of serum 7α-hydroxy-4-cholesten-3-one as a marker of bile acid malabsorption in dogs with chronic diarrhoea: a pilot study

Bile acid malabsorption is a common cause of chronic diarrhoea in people, however it has never previously been investigated in dogs, despite clinical suspicion of its existence. The goal of this study was to assess the feasibility of measuring serum 7α-hydroxy-4-cholesten-3-one (C4) in dogs, as a potential marker of bile acid malabsorption, and to see whether this is related to clinical disease severity or the presence of hypocobalaminaemia. Serum C4 concentration was measured in 20 clinically healthy control dogs and 17 dogs with chronic diarrhoea. Three of the 17 affected dogs (17.6 per cent) had a C4 concentration significantly above the range of clinically healthy dogs; these dogs were all poorly responsive to conventional therapy. These results suggest that bile acid malabsorption may be a clinically relevant disorder in dogs with chronic diarrhoea and serum C4 may be a useful tool to investigate this further.

The epidemiology of sepsis during rapid response team reviews in a teaching hospital

In a three-month retrospective study, we assessed the proportion of rapid response team (RRT) calls associated with systemic inflammatory response syndrome (SIRS) and sepsis. We also documented the site of infection (whether it was community- or hospital-acquired), antibiotic modifications after the call and in-hospital outcomes. Amongst 358 RRT calls, two or more SIRS criteria were present in 277 (77.4%). Amongst the 277 RRT calls with SIRS criteria, 159 (57.4%) fulfilled sepsis criteria in the 24 hours before and 12 hours after the call. There were 118 of 277 (42.6%) calls with SIRS criteria but no evidence of sepsis and 62 of 277 (22.3%) calls associated with both criteria for sepsis as well as an alternative cause for SIRS. Hence, 159 (44.4%) of all 358 RRT calls over the three-month study period fulfilled criteria for sepsis and in 97 (159-62) (27.1%) of the 358 calls, there were criteria for sepsis without other causes for SIRS criteria. The most common sites of infection were respiratory tract (86), abdominal cavity (38), urinary tract (26) and bloodstream (26). Infection was hospital-acquired in 91 (57.2%) and community-acquired in 67 (42.1%) cases, respectively. Patients were on antibiotics in 127 of 159 (79.9%) cases before the RRT call and antibiotics were added or modified in 76 of 159 (47.8%) cases after RRT review. The hospital length-of-stay of patients who received an RRT call associated with sepsis was longer than those who did not (16.0 [8.0 to 28.5] versus 10 days [6.0 to 18.0]; P=0.002).

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Partial trisomy 3p24.3 and partial monosomy 5p15.33: case report and a literature review

We report on a preterm neonate with a deletion of the distal short arm of chromosome 5p15.33 and partial trisomy of the distal short arm of chromosome 3p24.3. The patient was the first-born monozygotic twin. There were no pertinent facial or physical features except a small lower lip hemangioma. The neonate presented with cardiac defects, which included a patent ductus arteriosus, an atrial septal defect and ventricular septal defects. After 94 days of age, however, the patient died from superior vena cava syndrome, recurrent chylothoraces and generalized anasarca. Array comparative genomic hybridization (aCGH) using a custom oligonucleotide microarray (Agilent 180,000 probe platform revealed a terminal duplication of 1,128 oligonucleotide probes from 3pter to 3p24.3, spanning approximately 20.4 megabases (Mb), and a terminal deletion of 271 oligonucleotide probes from 5pter to 5p15.33, spanning approximately 4.3 Mb. This is the first report of a patient with partial trisomy 3p24.3 and partial monosomy 5p15.33 without major dysmorphic features.

Síndrome de Holt-Oram: caracterización de una nueva mutación

INTRODUCTION

Cardiomyelic syndromes encompass congenital heart disease and skeletal malformations of the upper limbs and are related to mutations in transcription factors with T-Box domains. Holt-Oram syndrome is caused by a dominant mutation in the TBX5 gene that alters the three-dimensional structure of the protein and its DNA binding function. Several point mutations and deletions in TBX5 have been reported in patients with the Holt-Oram syndrome phenotype.

PATIENTS AND METHODS

The proband was a boy with a large atrial septal defect ostium secundum type and a ventricular septal defect, diagnosed by clinical findings (heart murmur) and echocardiography. He also presented slightly hypoplastic thumbs with distal bilateral placement and an implantation index of 0.19 (compared with an average of 0.50 for his gestational age at birth). The boy was referred to the department of medical genetics to rule out 22q11.2 microdeletion syndrome.

RESULTS

Karyotype and fluorescence in situ hybridization at locus D22S75 were both normal. Because of his clinical findings, molecular study for Holt-Oram syndrome was indicated, leading to the finding of a mutation at intron 7 of TBX5, probably producing a splicing alteration of the gene and resulting in a protein truncated at its C-terminal end. The proband's parents presented the wild type sequence of the gene, thus indicating that the mutation was produced de novo, although a possible germinal mosaicism in the parents could not be ruled out.

CONCLUSIONS

Holt-Oram syndrome is the most frequent cause of cardiomyelic syndrome. All children with heart malformations and abnormalities of the upper limbs such as absent, hypoplastic, distally placed or triphalangic thumbs should undergo molecular studies for this syndrome.

Association of the dopamine transporter (DAT1) 10/10-repeat genotype with ADHD symptoms and response inhibition in a general population sample

Association between attention-deficit hyperactivity disorder (ADHD) and the 10-repeat allele of the dopamine transporter gene (DAT1) has been reported in independent clinical samples using a categorical clinical definition of ADHD. The present study adopts a quantitative trait loci (QTL) approach to examine the association between DAT1 and a continuous measure of ADHD behaviours in a general-population sample, as well as to explore whether there is an independent association between DAT1 and performance on neuropsychological tests of attention, response inhibition, and working memory. From an epidemiological sample of 872 boys aged 6-11 years, we recruited 58 boys scoring above the 90th percentile for teacher reported ADHD symptoms (SWAN ADHD scale) and 68 boys scoring below 10th percentile for genotyping and neuropsychological testing. A significant association was found between the DAT1 homozygous 10/10-repeat genotype and high-scoring boys (chi(2)square=4.6, P<0.03; odds ratio=2.4, 95% CI 1.1-5.0). Using hierarchical linear regression, a significant independent association was found between the DAT1 10/10-repeat genotype and measures of selective attention and response inhibition after adjusting for age, IQ, and ADHD symptoms. There was no association between DAT1 and any component of working memory. Furthermore, performance on tasks of selective attention although associated with DAT1 was not associated with SWAN ADHD high scores after controlling for age and IQ. In contrast, impairment on tasks that tapped sustained attention and the central executive component of working memory were found in high-scoring boys after adjusting for age and IQ. The results suggest that DAT1 is a QTL for continuously distributed ADHD behaviours in the general population and the cognitive endophenotype of response inhibition.

Are medullary breast cancers an indication for BRCA1 mutation screening? A mutation analysis of 42 cases of medullary breast cancer

Recommended guidelines have limited breast cancer gene ( BRCA1 ) mutation testing to individuals with a personal or family history of early onset breast and/or ovarian cancer, and those with multiple affected close relatives. Such large breast cancer families are rare in the general population, limiting the clinical application of the BRCA1 discovery. Previous reports have suggested an association between medullary breast cancer and BRCA1 mutation carriers. To test the feasibility of using these rare histological subtypes as an alternative to epidemiological factors, 42 cases of medullary cancer unselected for family history were screened for BRCA1 point mutations and large exon rearrangements. The large majority (83%) of these patients did not have significant family of breast or ovarian cancer. Two deleterious mutations resulting in a premature stop codon, and one exon 13 duplication were found. All mutations were detected in patients with typical medullary cancer, who had family history of multiple breast and ovarian cancers. Our findings suggest that medullary breast cancers are not an indication for BRCA1 mutation screening in the absence of significant family risk factors.

Avian cryptococcosis

Clinical and laboratory findings in 15 unreported cases of avian cryptococcosis from Australia were collated and contrasted with 11 cases recorded in the literature. Cryptococcus species produced localized invasive disease of the upper respiratory tract of captive parrots living in Australia. This resulted in signs referable to mycotic rhinitis or to involvement of structures contiguous with the nasal cavity, such as the beak, sinuses, choana, retrobulbar space and palate. Parrots of widely differing ages were affected and of the seven birds for which sex was determinable, six were male. Cryptococcus bacillisporus (formerly C. neoformans var. gattii) accounted for four of five infections in which the species or variety was determinable, suggesting that exposure to eucalyptus material may be a predisposing factor. In these cases, Cryptococcus appeared to behave as a primary pathogen of immunocompetent hosts. One tissue specimen was available from an Australian racing pigeon with minimally invasive subcutaneous disease; immunohistology demonstrated a C. neoformans var. grubii (formerly C. neoformans var. neoformans serotype A) infection, presumably subsequent to traumatic inoculation of yeast cells into the subcutis. Two similar cases had been reported previously in pigeons domiciled in America. Data for parrots, one pigeon and other birds studied principally in America and Europe (and likely infected with C. neoformans) suggested a different pattern of disease, more suggestive of opportunistic infection of immunodeficient hosts. In this cohort of patients, the organism was not restricted to cool superficial sites such as the upper respiratory tract or subcutis. Instead, infections typically penetrated the lower respiratory tract or disseminated widely to a variety of internal organs. Finally, three captive North Island brown kiwis, one residing in Australia, the other two in New Zealand, died as a result of severe diffuse cryptococcal pneumonia (two cases) or widely disseminated disease (one case). C. bacillisporus strains were isolated from all three cases, as reported previously for another kiwi with disseminated disease in New Zealand.

High throughput screening of human subtelomeric DNA for copy number changes using multiplex amplifiable probe hybridisation (MAPH)

BACKGROUND

Subtelomeric regions of the human genome are gene rich, with a high level of sequence polymorphism. A number of clinical conditions, including learning disability, have been attributed to subtelomeric deletions or duplications, but screening for deletion in these regions using conventional cytogenetic methods and fluorescence in situ hybridisation (FISH) is laborious. Here we report that a new method, multiplex amplifiable probe hybridisation (MAPH), can be used to screen for copy number at subtelomeric regions.

METHODS

We have constructed a set of MAPH probes with each subtelomeric region represented at least once, so that one gel lane can assay copy number at all chromosome ends in one person. Each probe has been sequenced and, where possible, its position relative to the telomere determined by comparison with mapped clones.

RESULTS

The sensitivity of the probes has been characterised on a series of cytogenetically verified positive controls and 83 normal controls were used to assess the frequency of polymorphic copy number with no apparent phenotypic effect. We have also used MAPH to test a cohort of 37 people selected from males referred for fragile X syndrome testing and found six changes that were confirmed by dosage PCR.

CONCLUSIONS

MAPH can be used to screen subtelomeric regions of chromosomes for deletions and duplications before confirmation by FISH or dosage PCR. The high throughput nature of this technique allows it to be used for large scale screening of subtelomeric copy number, before confirmation by FISH. In practice, the availability of a rapid and efficient screen may allow subtelomeric analysis to be applied to a wider selection of patients than is currently possible using FISH alone.

Androgen-secreting adrenal adenomas

BACKGROUND

The androgen source in women with hirsutism and signs of virilism may be the ovary or adrenal gland.

CASES

Three patients with androgen excess are reported. Two had hyperandrogenemia and Cushing syndrome with an adrenal mass greater than 5.5 cm; the third had a small adrenal adenoma secreting only testosterone and responsive to human chorionic gonadotropin. In all cases, the pathologic report from surgery and the long-term resolution of symptoms confirmed the benign nature of the tumors.

CONCLUSION

Basal and dynamic hormonal tests cannot precisely differentiate ovarian from adrenal tumors. Adrenal adenomas must be considered as a cause of hyperandrogenic syndrome.

Large-insert BAC/YAC libraries for selective re-isolation of genomic regions by homologous recombination in yeast

We constructed representative large-insert bacterial artificial chromosome (BAC) libraries of two human pathogens (Trypanosoma brucei and Giardia lamblia) using a new hybrid vector, pTARBAC1, containing a yeast artificial chromosome (YAC) cassette (a yeast selectable marker and a centromere). The cassette allows transferring of BACs into yeast for their further modification. Furthermore, the new hybrid vector provides the opportunity to re-isolate each DNA insert without construction of a new library of random clones. Digestion of a BAC DNA by an endonuclease that has no recognition site in the vector, but which deletes most of the internal insert sequence and leaves the unique flanking sequences, converts a BAC into a TAR vector, thus allowing direct gene isolation. Cotransformation of a TAR vector and genomic DNA into yeast spheroplasts, and subsequent recombination between the TAR vector's flanking ends and a specific genomic fragment, allows rescue of the fragment as a circular YAC/BAC molecule. Here we prove a new cloning strategy by re-isolation of randomly chosen genomic fragments of different size from T. brucei cloned in BACs. We conclude that genomic regions of unicellular eukaryotes can be easily re-isolated using this technique, which provides an opportunity to study evolution of these genomes and the role of genome instability in pathogenicity.

Differential impact of the FMR-1 full mutation on memory and attention functioning : a neuropsychological perspective

Memory and attention processing were examined in a group of 15 adult Fragile-X syndrome (FXS) males with Fragile-X mental retardation 1 (FMR-1) full mutation and compared to two control groups: a learning disabled (LD) control and a normal functioning control. Performance was assessed across a wide range of tasks including working memory, recognition memory, selective attention, sustained attention, and attentional switching. All three groups performed at a comparable level on recognition memory tasks, and the Fragile-X males and LD control group performed worse than the control group on tasks of working memory and sustained attention. On a task of executive function, the Fragile-X males demonstrated a significant deficit in comparison to the LD control group and the normal control group, but performed better than the LD control group and at a comparable level to the control group on tasks of selective attention. Molecular analyses of the lymphocyte DNA provided little evidence for a correlation between expansion size and performance on tasks of memory and attention. The findings from the present study are discussed in the context of functional neuroimaging and brain-behavior-molecular correlates.

Loss of heterozygosity in bilateral breast cancer

Women who develop bilateral breast cancer at an early age are likely to harbour germline mutations in breast cancer susceptibility genes. The aim of this study was to test for concordant genetic changes in left and right breast cancer of young women (age < 50) with bilateral breast cancer that may suggest an inherited breast cancer predisposition. Microsatellite markers were used to test for loss of heterozygosity (LOH) in left and right tumours for 31 women with premenopausal bilateral breast cancer. Markers adjacent to or within candidate genes on 17p (p53), 17q (BRCA1), 13q (BRCA2), 11q (Ataxia Telangiectasia-ATM) and 3p (FHIT) were chosen. Mutational testing for BRCA1 and BRCA2 was performed for cases where blood was available. Concordant LOH in both left and right tumours was demonstrated for at least one of the markers tested in 16/31(54%) cases. Where allelic loss was demonstrated for both left and right breast cancer, the same allele was lost on each occasion. This may suggest a common mutational event. Four cases showed concordant loss of alleles in both left and right breast cancer at D17S791 (BRCA1). BRCA1 mutations were identified in two of these cases where blood was available. Four cases showed concordant LOH at D13S155 (BRCA2). Concordant LOH was further demonstrated in seven cases for D11S1778 (ATM) and four cases for D3S1300 (which maps to the FHIT gene), suggesting a possible role for these tumour suppressor genes in this subgroup of breast cancer patients. No concordant allelic loss was demonstrated for D17S786 suggesting that germline mutations in p53 are unlikely in such cases of bilateral breast cancer.

Measurement of locus copy number by hybridisation with amplifiable probes

Despite its fundamental importance in genome analysis, it is only recently that systematic approaches have been developed to assess copy number at specific genetic loci, or to examine genomic DNA for submicro-scopic deletions of unknown location. In this report we show that short probes can be recovered and amplified quantitatively following hybridisation to genomic DNA. This simple observation forms the basis of a new approach to determining locus copy number in complex genomes. The power and specificity of multiplex amplifiable probe hybridisation is demonstrated by the simultaneous assessment of copy number at a set of 40 human loci, including detection of deletions causing Duchenne muscular dystrophy and Prader-Willi/Angelman syndromes. Assembly of other probe sets will allow novel, technically simple approaches to a wide variety of genetic analyses, including the potential for extension to high resolution genome-wide screens for deletions and amplifications.

A neuropsychological-genetic profile of atypical cri du chat syndrome: implications for prognosis

Cri du chat syndrome is associated with a deletion on the short arm of chromosome 5. The main diagnostic feature is a high pitched, cat-like cry which has recently been localised to 5p15.3 and is separate from the remaining clinical features of the syndrome, which have been localised to 5p15.2. The present study describes a family of four who have a deletion slightly distal (5p15.3) to the critical region. Detailed neuropsychological evaluations indicated a similar pattern of cognitive performance to that reported for subjects with typical CDCS but with only minimal intellectual impairment. In addition, in this family the 5p deletion is transmitted in an autosomal dominant fashion, contrasting with most cases of CDCS, which are either de novo or occur as an unbalanced product of a balanced translocation in a normal parent. This study confirms the importance of differentiating between 5p deletions that coincide with the typical cri du chat phenotype which includes severe to profound learning disability and deletions that only delete the distal critical region that coincides with a milder degree of cognitive impairment and a much improved prognosis.

Spatial cognition in males with Fragile-X syndrome: evidence for a neuropsychological phenotype

Spatial performance in a group of young Fragile-X syndrome males with FMR-1 full mutation was compared to a learning disabled control group comprising young Down's syndrome males and two control groups of mainstream schoolchildren. Performance was assessed across a wide range of spatial tasks including visuo-construction, visuo-spatial memory, visuo-motor, and visuo-perception. The findings indicate a task-specific rather than global deficit in spatial performance in Fragile-X males with visuo-constructive and visuo-motor skills most vulnerable. Molecular analysis of the lymphocyte DNA found minimal evidence for a correlation between CGG expansion size and spatial performance, although tasks with a visuo-perceptual component correlated negatively with expansion size indicating that the further away the number of repeats are from the 200 threshold the poorer the performance.

The nature of the spatial deficit in young females with Fragile-X syndrome: a neuropsychological and molecular perspective

Spatial performance in a group of young Fragile-X syndrome females with FMR-1 full mutation was compared to two control groups of mainstream schoolchildren. Performance was assessed across a wide range of spatial tasks including visuo-spatial, visuo-construction, visuo-motor, visuo-perception and spatial-memory. A spatial deficit emerged only on those tasks which comprised a visuo-constructive component, with the Fragile-X group performing worse overall. All other tasks were performed at a comparable level across the three groups. Molecular analysis of the lymphocyte DNA found minimal evidence for a correlation between expansion size and spatial performance. In addition, there was no evidence for a correlation between the proportion of active to inactive unmethylated FMR-1 genes (activation ratio) and spatial performance. These results conflict with recent reports of a correlation between activation ratio and intellectual functioning.

University students' knowledge of STDs: labels, symptoms and transmission

A sample of 630 Victorian university students, aged between 17 and 24, completed a questionnaire on knowledge of sexually transmitted diseases (STDs). Overall students demonstrated moderate levels of knowledge about the names of diseases which are transmitted by sexual contact, symptoms and medical facts and transmission modes of common STDs. However, they had more knowledge about the labels than they did about symptoms and transmission modes and were misinformed about certain clinical aspects of STDs. It was found that the different levels of knowledge varied with the type of STD. Knowledge about symptoms of transmission did not correlate with a disease's incidence or clinical aspects. Sexual experience and having an Australian born mother correlated with higher scores. This study suggests that young people do not have high levels of knowledge about common STDs they may encounter. Identification of a label is of limited personal value if there is no concurrent knowledge about disease transmission and prognosis.

A study of FRAXE in mentally retarded individuals referred for fragile X syndrome (FRAXA) testing in the United Kingdom

The folate-sensitive fragile site FRAXE is located in proximal Xq28 of the human X chromosome and lies approximately 600 kb distal to the fragile X syndrome (FRAXA) fragile site at Xq27.3. The cytogenetic expression of FRAXE is thought to be associated with mental handicap, but this is usually mild compared to that of the more common fragile X syndrome that is associated with the expression of the FRAXA fragile site. The exact incidence of FRAXE mental retardation is uncertain. We describe here the results of a U.K. survey designed to assess the frequency of FRAXE in a population of individuals referred for fragile X syndrome testing and found to be negative for expansion events at the FRAXA locus. No FRAXE expansion events were found in 362 cytogenetically negative males studied, and one expansion event was identified in a sample of 534 males for whom cytogenetic analyses were either unrecorded or not performed. Further FRAXE expansion events were detected in two related females known to be cytogenetically positive for a fragile site in Xq27.3-28. To gain insight into the FRAXE phenotype, the clinical details of the identified FRAXE male plus three other FRAXE individuals identified through previous referrals for fragile X syndrome testing are presented. For the population studied, we conclude that FRAXE mental retardation is a relatively rare but significant form of mental retardation for which genetic diagnosis would be appropriate.

A comparison of epidural diamorphine with intramuscular papaveretum following caesarean section

Following caesarean section carried out under epidural blockade using local anaesthetic only, 40 consenting women were randomly allocated to receive either epidural diamorphine 2.5-5 mg in 10 ml physiological saline and intramuscular saline or epidural saline and intramuscular papaveretum 10-20 mg, dosage depending on weight, when the pain returned. When analgesia was next requested the alternative treatment was given. A visual analogue pain score was recorded before and 15, 30, 60, 120, 180 and 240 min after the first treatment. Respirations were counted and symptoms noted. On the following day the mother was asked whether she preferred the first or the second treatment. Both treatments produced a reduction in pain score but analgesia was significantly better with epidural diamorphine and the duration of action (8.5 +/- 5.2 h) was significantly longer than that following intramuscular papaveretum (4.1 +/- 2.3 h, P < 0.01). Two mothers who received epidural diamorphine initially required no further analgesia. No difference in respiratory rate was noted but side-effects were more frequent with epidural diamorphine. Despite this more women preferred this treatment. Because of enhanced mobility provided by good analgesia epidural diamorphine is worth offering to women following caesarean section.

Haemodynamic adjustments to mental stress in normotensives and subjects with mildly elevated blood pressure

Cardiac output, heart rate, stroke volume, pre-ejection period, total peripheral resistance, systolic and diastolic blood pressure, and oxygen consumption were monitored or derived in young men with mildly elevated casual blood pressures and unambiguously normotensive control subjects before, during, and after exposure to a mental arithmetic stress. Measurements were also taken while subjects underwent graded dynamic exercise. This permitted cardiac output-oxygen consumption regression equations to be calculated and, as a consequence, cardiac output during mental stress to be represented as additional cardiac output. Systolic and diastolic blood pressure were higher during all phases of the study in the mildly elevated blood pressure group. An overall groups effect during the mental stress phase of the experiment was observed for cardiac output and pre-ejection period, and the effect for stroke volume was close to significance. Significant Groups X Periods interactions were found for cardiac output and additional cardiac output, and the heart rate effect was nearly significant. Post-hoc comparisons here indicated that, in the main, group differences in these cardiac variables were more evident during the mental arithmetic stress than during the pre- and post-task baseline periods. Total peripheral resistance did not differ reliably between groups and the cardiac effects were specific to the mental stress phase of the study.

Atropine-induced heart rate changes: a comparison between midazolam-fentanyl-propofol-N2O and midazolam-fentanyl-thiopentone-enflurane-N2O anaesthesia

Atropine-induced heart rate (HR) changes were studied in 19 patients (ASA physical status I) during anaesthesia-maintained predominantly with propofol-N2O or thiopentone-enflurane-N2O. Ten patients (Group A) received midazolam (0.07 mg.kg-1), fentanyl (1 microgram.kg-1), propofol (2 mg.kg-1) and succinylcholine (1 mg.kg-1). Following tracheal intubation, anaesthesia was maintained with propofol (6 mg.kg-1.hr-1), N2O (67 per cent) and O2 (33 per cent). In nine patients (Group B) thiopentone (4 mg.kg-1) was substituted for propofol and anaesthesia maintained with N2O (67 per cent) O2 (33 per cent), and enflurane (0.5 per cent inspired concentration). The study was non-randomised because Group B patients were only included if HR before administration of atropine less than 90 beats.min-1. IPPV was performed in all patients using a Manley ventilator (minute vol. 85 ml.kg-1; tidal vol. 7 ml.kg-1). Ten minutes after tracheal intubation, incremental doses of atropine (equivalent cumulative doses: 1.8, 3.6, 7.2, 14.4, 28.8 micrograms.kg-1) were administered at two-minute intervals and HR responses calculated during the last 45 sec of each intervening period. No differences were observed between the groups following 1.8 and 3.6 micrograms.kg-1 atropine, but propofol-N2O anaesthesia was associated with reduced responses (P less than 0.01) following 7.2, 14.4 and 28.8 micrograms.kg-1 atropine. These results suggest that there is a predominance of parasympathetic influences during propofol-N2O anaesthesia compared with thiopentone-enflurane-N2O anaesthesia.

An analgesiometry system for use in rabbits with some preliminary data on the effects of buprenorphine and lofentanil

A low cost infrared skin heating system has been designed to measure the efficacy of analgesics in rabbits. Following construction of a prototype, it was used to assess the effect of buprenorphine given subcutaneously and per rectum. Buprenorphine administered subcutaneously has a rapid onset of action, but its duration (8-10 h) appears slightly shorter than has been suggested previously; rectal administration appears to prolong its effect. Preliminary data show that lofentanil has a longer duration of action than buprenorphine and it may prove, therefore, to be a valuable long-acting analgesic in the rabbit.

Inferior pulmonary ligament lymphadenopathy: demonstration by computed tomography

Inferior pulmonary ligament lymphadenopathy is common in bronchogenic carcinoma and may also occur in lymphoma and potentially in any condition which may cause intrathoracic lymphadenopathy. Despite the apparent frequency with which inferior pulmonary ligament lymphadenopathy occurs, we have been unable to find a description of the computed tomographic findings of this condition. In a patient with lymphoma, we found inferior pulmonary ligament lymphadenopathy by computed tomography as an oval, elongated soft-tissue density arising within the inferior pulmonary ligament and still attached to the mediastinum by a piece of the normal ligament. We believe that this appearance should be sufficient for the correct computed tomographic diagnosis of inferior pulmonary ligament lymphadenopathy.

Prognosis for babies born with fused eyelids

The overall mortality for babies referred to our unit with fused eyelids was 68.7%; but when severe skin bruising was present only one of 18 babies survived (5.6%). This compares with a survival rate of 75% for those not bruised at or soon after birth. Skin bruising invariably indicates a very poor prognosis in babies born with fused eyelids.