Chest CT screening for COVID-19 in elective and emergency surgical patients: experience from a UK tertiary centre

AIM

To determine the incidence of possible COVID-19-related lung changes on preoperative screening computed tomography (CT) for COVID-19 and how their findings influenced decision-making. To also to determine whether the patients were managed as COVID-19 patients after their imaging findings, and the proportion who had SARS-CoV2 reverse transcriptionpolymerase chain reaction (RT-PCR) testing.

MATERIALS AND METHODS

A retrospective study was undertaken of consecutive patients having imaging prior to urgent elective surgery (n=156) or acute abdominal imaging (n=283). Lung findings were categorised according to the British Society of Thoracic Imaging (BSTI) guidelines. RT-PCR testing, management, and outcomes were determined from the electronic patient records.

RESULTS

3% (13/439) of CT examinations demonstrated findings of classic/probable COVID-19 pneumonia, whilst 4% (19/439) had findings indeterminate for COVID-19. Of the total cohort, 1.6% (7/439) subsequently had confirmed RT-PCR-positive COVID-19. Importantly, all the patients with a normal chest or alternative diagnoses on CT who had PCR testing within the next 7 days, had a negative RT-PCR (92/407). There was a change in surgical outcome in 6% (10/156) of the elective surgical cohort with no change to surgical management was demonstrated in the acute abdominal emergency cohort requiring surgery (2/283).

CONCLUSION

There was a 7% (32/439) incidence of potential COVID-19-related lung changes in patients having preoperative CT. Although this altered surgical management in the elective surgical cohort, no change to surgical management was demonstrated in the acute abdominal emergency cohort requiring surgery.

Peripheral nerves are pathologically small in cerebellar ataxia neuropathy vestibular areflexia syndrome: a controlled ultrasound study

BACKGROUND AND PURPOSE

Sensory neuronopathy is a cardinal feature of cerebellar ataxia neuropathy vestibular areflexia syndrome (CANVAS). Having observed that two patients with CANVAS had small median and ulnar nerves on ultrasound, we set out to examine this finding systematically in a cohort of patients with CANVAS, and compare them with both healthy controls and a cohort of patients with axonal neuropathy. We have previously reported preliminary findings in seven of these patients with CANVAS and seven healthy controls.

METHODS

We compared the ultrasound cross-sectional area of median, ulnar, sural and tibial nerves of 14 patients with CANVAS with 14 healthy controls and 14 age- and gender-matched patients with acquired primarily axonal neuropathy. We also compared the individual nerve cross-sectional areas of patients with CANVAS and neuropathy with the reference values of our laboratory control population.

RESULTS

The nerve cross-sectional area of patients with CANVAS was smaller than that of both the healthy controls and the neuropathy controls, with highly significant differences at most sites (P < 0.001). Conversely, the nerve cross-sectional areas in the upper limb were larger in neuropathy controls than healthy controls (P < 0.05). On individual analysis, the ultrasound abnormality was sufficiently characteristic to be detected in all but one patient with CANVAS.

DISCUSSION

Small nerves in CANVAS probably reflect nerve thinning from loss of axons due to ganglion cell loss. This is distinct from the ultrasound findings in axonal neuropathy, in which nerve size was either normal or enlarged. Our findings indicate a diagnostic role for ultrasound in CANVAS sensory neuronopathy and in differentiating neuronopathy from neuropathy.

A score for the prediction of cardiovascular events in the hypertensive aged

BACKGROUND

With few exceptions, tools used to estimate cardiovascular disease (CVD) risk in those without prior events are based mainly on data from middle-aged subjects. Given the ever increasing number of older people, many with hypertension, a risk score relevant to this group is warranted. Our aim was to develop a cardiovascular risk equation suitable for risk prediction in elderly, hypertensive populations.

METHODS

We utilized cardiovascular end point data from 4.1 years median follow-up in 5,426 hypertensive subjects without previous CVD from the Second Australian National Blood Pressure Study (ANBP2). Our risk model, based on Cox regression, was developed using 75% of subjects without evident CVD (n = 4,072), randomly selected and stratified by age and gender, and internally validated using the remaining 25%. The model was also externally validated against the Dubbo Study dataset.

RESULTS

The final model included sex, age, physical activity in the 2 weeks prior to entry into study, family history, use of anticoagulants, centrally acting antihypertensive agents or diabetes medication, and an interaction term for sex and diabetes medication. The C-statistic was 0.65 (0.62-0.67) for our predictive model on the model development dataset and 0.62 (0.57-0.67) on the internal validation dataset. The Dubbo Data C-statistic for CVD was 0.68 (95% CI 0.65-0.71).

CONCLUSIONS

All models performed similarly. Because of greater ease of implementation, we recommend that existing algorithms be extended into older age groups.

Evidence that systemic gentamicin suppresses premature stop mutations in patients with cystic fibrosis

Here we report the effects of gentamicin treatment on cystic fibrosis transmembrane regulator (CFTR) production and function in CF airway cells and patients with CF with premature stop mutations. Using immunocytochemical and functional [6-methoxy-N- (3-sulfopropyl) quinolinium (SPQ)-based] techniques, ex vivo exposure of airway cells from stop mutation CF patients led to the identification of surface-localized CFTR in a dose-dependent fashion. Next, five patients with CF with stop mutations and five CF control subjects were treated with parenteral gentamicin for 1 wk, and underwent repeated in vivo measures of CFTR function (nasal potential difference [PD] measurements and sweat chloride [Cl(-)] testing). During the treatment period, the number of nasal PD readings in the direction of Cl(-) secretion was increased approximately 3-fold in the stop mutation patient group compared with controls (p < 0.001), and four of five stop mutation patients with CF had at least one reading during gentamicin treatment with a Cl(-) secretory response of more than -5 mV (hyperpolarized). A response of this magnitude was not seen in any of the CF control subjects (p < 0.05). In an independent series of experiments designed to test the ability of repeat nasal PDs to detect wild-type CFTR function, evidence of Cl(-) secretion was seen in 88% of control (non-CF) nasal PDs, and 71% were more than -5 mV hyperpolarized. Together, these results suggest that gentamicin treatment can suppress premature stop mutations in airway cells from patients with CF, and produce small increases in CFTR Cl(-) conductance (as measured by the nasal PD) in vivo.

Country report: Australia

The last 10 years has been an interesting time for Australian medical education despite reduced funding.

WORKFORCE

There are five main workforce trends: a rural/urban maldistribution, a need for more specialists, public hospital staffing difficulties, increasing female practitioners and under-representation of indigenous practitioners.

ISSUES FACING THE DEANS

Lack of resources is a problem facing Deans, with pressure for clinical service in teaching hospitals. Entrepreneurial activities have been undertaken including the enrollment of overseas students. Medical schools have also responded to important government initiatives.

DEVELOPMENTS IN MEDICAL EDUCATION

Australia's 11 medical schools have undergone significant reform in the last decade. There is a mix of four (graduate), five and six year courses. AUSTRALIA'S NEW MEDICAL SCHOOL: James Cook University opened the first medical school in northern Australia in 2000. The School admits students from rural, northern Australian and indigenous backgrounds. It has a strong regional mission. RURAL AND COMMUNITY-BASED EDUCATION: Government funding to address the maldistribution of the workforce has led to the establishment of rural clubs, Departments of Rural Health and community-based programs.

THE FIRST TWO POSTGRADUATE YEARS

There have been recent moves to improve education in the two years following graduation. This includes the initiation of national projects in curriculum and assessment.

POSTGRADUATE AND CONTINUING MEDICAL EDUCATION

Postgraduate programs in Australia are being reformed to build on the changes in undergraduate education. CME is also under review.

CONCLUSION

Australian medical educators should build on the recent reforms and take on some of the new directions in medical education.

A clinical inflammatory syndrome attributable to aerosolized lipid-DNA administration in cystic fibrosis

Immunologic reactivity to lipid-DNA conjugates has traditionally been viewed as less of an issue than with viral vectors. We performed a dose escalation safety trial of aerosolized cystic fibrosis transmembrane conductance regulator (CFTR) cDNA to the lower airways of eight adult cystic fibrosis patients, and monitored expression by RT-PCR. The cDNA was complexed to a cationic lipid amphiphile (GL-67) consisting of a cholesterol anchor linked to a spermine head group. CFTR transgene was detected in three patients at 2-7 days after gene administration. Four of the eight patients developed a pronounced clinical syndrome of fever (maximum of 103.3EF), myalgias, and arthralgia beginning within 6 hr of gene administration. Serum IL-6 but not levels of IL-8, IL-1, TNF-alpha, or IFN-gamma became elevated within 1-3 hr of gene administration. No antibodies to the cationic liposome or plasmid DNA were detected. We found that plasmid DNA by itself elicited minimal proliferation of peripheral blood mononuclear cells taken from study patients, but led to brisk immune cell proliferation when complexed to a cationic lipid. Lipid and DNA were synergistic in causing this response. Cellular proliferation was also seen with eukaryotic DNA, suggesting that at least part of the immunologic response to lipid-DNA conjugates is independent of unmethylated (E. coli-derived) CpG sequences that have previously been associated with innate inflammatory changes in the lung.

Catatonia in autistic spectrum disorders

BACKGROUND

The clinical pictures of autistic spectrum disorders include features described in catatonia.

AIMS

To examine the severe exacerbation of the catatonic features of autistic disorders in adolescence or early adult life, which occurs in some individuals.

METHOD

A semi-structured interview schedule was used to collect information from parents or other care-givers concerning 506 referrals to a specialist clinic for autistic spectrum disorders. Individuals with severe exacerbation of catatonic features were compared with a same-age group of referrals without this type of deterioration in skills and behaviour.

RESULTS

Seventeen per cent of referrals aged 15 or over had severe exacerbation of catatonic features. They were significantly more likely than the comparison group to have had, before the onset of the change in behaviour, impaired language and passivity in social interaction.

CONCLUSIONS

Catatonia is a later complication of autistic spectrum disorders, which adds considerably to the burden of caring. More research is needed to identify causes, neuropathology, and early signs of vulnerability.

Changes in skills for people with intellectual disability: a follow-up of the Camberwell Cohort

The skills of a total population of children with severe intellectual disability and/or autism from Camberwell, South London, UK, and the initial follow-up data, taken when the subjects were adolescents and young adults (Shah 1986), are described in the present study. Changes in skills over time are presented within the categories of communication, self-care, and educational and cognitive skills, as assessed by the Handicaps, Behaviours and Skills schedule. The results indicated that skills had improved in many areas between times 1 and 2, but that this improvement was more noticeable for the children who had been youngest at time 1. The implications of these results and predictions for a further follow-up study are discussed.

Autism: not an extremely rare disorder

OBJECTIVE

To study autism over time in order to ascertain whether there has been an increase in its prevalence in recent years.

METHOD

All English language papers on the prevalence of autism were reviewed. Ten of the studies retrieved were not used in the final analysis because they did not meet full criteria for inclusion in the review. The remaining 20 studies, published between 1966 and 1997, were subdivided into US studies (n=2) and non-US studies (n=18), and the latter group was subdivided into four 8-year periods.

RESULTS

The early studies yielded prevalence rates of under 0.5 in 1000 children, whereas the later ones showed a mean rate of about 1 in 1000. There was a marked difference in prevalence rates between those studies that included some children born before 1970 (low rates) and those that included only children born in 1970 and after (high rates). This is probably due to the lower rates obtained by use of criteria strictly based on Kanner's description of his syndrome. The US studies reported atypically low rates. There was a highly significant estimated increase with calendar year in the non-US studies (3.8% per year).

CONCLUSION

It is concluded that autism is considerably more common than was previously believed. The possible reasons for the higher reported rates are discussed.

A screening questionnaire for Asperger syndrome and other high-functioning autism spectrum disorders in school age children

The high-functioning Autism Spectrum Screening Questionnaire (ASSQ) is a 27-item checklist for completion by lay informants when assessing symptoms characteristic of Asperger syndrome and other high-functioning autism spectrum disorders in children and adolescents with normal intelligence or mild mental retardation. Data for parent and teacher ratings in a clinical sample are presented along with various measures of reliability and validity. Optimal cutoff scores were estimated, using Receiver Operating Characteristic analysis. Findings indicate that the ASSQ is a useful brief screening device for the identification of autism spectrum disorders in clinical settings.

Control and cardiovascular risk factors of hypertension. An assessment of a sample of patients

OBJECTIVES

To monitor the documentation of blood pressure measurements and other cardiovascular risk factors in general practice patients with hypertension.

METHOD

Twenty-five case notes of patients diagnosed as hypertensive were randomly selected from each of 58 participating general practitioners in suburban general practice in Adelaide, South Australia and were monitored by two registered nurses.

MAIN OUTCOME MEASURES

to assess whether blood pressure readings, weight, smoking history, alcohol intake and family history were documented, and whether electrocardiogram, plasma lipids, urinalysis and biochemical screen (which includes blood urea nitrogen, creatinine, glucose, electrolytes and uric acid) had been undertaken.

RESULTS

Data from 1446 hypertensive patients showed that for the last three blood pressure values recorded, 483 (33%) had an average level of 140/90 mm Hg or less and 1100 (76%) had an average of 160/95 mm Hg or less. The other cardiovascular risk factors selected were variably recorded, with biochemical screen being most commonly recorded [1198 (83%)] and family history [423 (29%)] the least.

CONCLUSIONS

Inadequacies in the control of hypertension and in the documentation of other cardiovascular risk factors suggest that further educational initiatives are required in this common chronic illness.

Delayed language onset as a predictor of clinical symptoms in pervasive developmental disorders

DSM-IV states that Asperger Disorder may be distinguished from Autistic Disorder by a lack of a delay in early language development. The aim of this study was to establish whether the presence or absence of early language delay would predict autistic symptomatology in children diagnosed with a PDD/autism spectrum disorder. Forty-six language-delayed and 62 normal language onset individuals (M age 11 years) were compared on ICD-10 research criteria and DSM-IV criteria, receptive language, and developmental history variables. Retrospective data were also obtained to determine whether language onset predicted autism symptomatology when young (< 6 years). We found that early language delay predicts more autistic symptomatology when young, but not at an older age. Early language delay is also associated with developmental motor milestone delays and lower receptive language abilities. The results question the use of early language delay as a valid discriminating variable between PDD subgroups.

Are there subgroups within the autistic spectrum? A cluster analysis of a group of children with autistic spectrum disorders

Comprehensive data on the developmental history and current behaviours of a large sample of high-functioning individuals with diagnoses of autism, Asperger's syndrome, or other related disorder were collected via parent interviews. This provided the basis for a taxonomic analysis to search for subgroups. Most participants also completed theory of mind tasks. Three clusters or subgroups were obtained; these differed on theory of mind performance and on verbal abilities. Although subgroups were identified which bore some relationship to clinical differentiation of autistic, Asperger syndrome, and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS) cases, the nature of the differences between them appeared strongly related to ability variables. Examination of the kinds of behaviours that differentiated the groups suggested that a spectrum of autistic disorders on which children differ primarily in term of degrees of social and cognitive impairments could explain the findings.

The addition of mibefradil to chronic hydrochlorothiazide therapy in hypertensive patients is associated with a significant antihypertensive effect

OBJECTIVE

To evaluate the antihypertensive efficacy, tolerability, safety, and dose-response characteristics of the novel calcium antagonist, mibefradil, in combination with a diuretic regimen.

DESIGN

A multinational, double-blind, randomised, placebo-controlled, parallel-design trial.

METHODS

Three hundred and seven patients whose mild-to-moderate essential hypertension remained uncontrolled after 4 weeks of treatment with hydrochlorothiazide (HCTZ) 25 mg/day and placebo were randomised to receive combined treatment with HCTZ and once-daily doses of 12.5, 25, 50, or 100 mg of mibefradil or placebo. After 8 weeks of combined treatment, HCTZ was withdrawn and the mibefradil groups continued on their respective doses for an additional 6 weeks.

RESULTS

After 8 weeks, the addition of once-daily doses of mibefradil to the initial HCTZ regimen resulted in clinically relevant, dose-related reductions in sitting diastolic blood pressure (SDBP) and sitting systolic blood pressure (SSBP) at trough, which were significantly greater in the 50 and 100 mg dose groups compared to the placebo group (P < or = 0.003). Placebo-corrected treatment effects on SDBP and SSBP at the end of the combined treatment period relative to baseline were, respectively, -4.1 and -8.0 mm Hg in the 50 mg mibefradil group and -9.5 and -8.0 mm Hg in the 100 mg mibefradil group. Therapeutic response rates to combination mibefradil and HCTZ therapy were high and dose related, reaching 82% for SDBP in the 100 mg group.

CONCLUSIONS

The addition of once-daily doses of 50 or 100 mg of mibefradil to patients whose hypertension is not controlled by HCTZ alone is well tolerated and effective in improving BP control.

Comparison of clinical symptoms in autism and Asperger's disorder

OBJECTIVE

To determine what clinical symptoms clinicians have been using to distinguish between Asperger's disorder (AsD) and autistic disorder (AD).

METHOD

Parents of children and adolescents with high-functioning AD (n = 48) and AsD (n = 69) were given a structured interview based on DSM-III-R and ICD-10 diagnostic criteria. Information regarding early and current symptom presentation and family, developmental, and verbal mental age information were collected. Logistic regression analyses were conducted to determine which variables best predicted clinician's diagnosis.

RESULTS

A number of clinical variables predicted diagnosis. Delayed language onset was the only variable of the family and developmental variables that predicted diagnosis. The AsD group was also significantly higher than the AD group in verbal mental age.

CONCLUSION

Clinicians appear to be diagnosing AsD and AD on the basis of published research and case study accounts. The findings question whether DSM-IV and ICD-10 criteria adequately describe the AsD individual, particularly in the communication domain.

An audit of third generation cephalosporin prescribing in a tertiary care hospital

BACKGROUND

There is increasing resistance to commonly used antibiotics, including third generation cephalosporins, and an increasing cost burden.

AIMS

To assess the appropriateness of prescribing of third generation cephalosporin antibiotics in a tertiary teaching hospital.

METHODS

Prescriptions of third generation cephalosporins (ceftriaxone, cefotaxime and ceftazidime) to inpatients were identified prospectively by the Hospital Pharmacy Department for a six week period during May-June 1994. Clinical data and indications were obtained from patient records and, when necessary, by interviewing the prescriber and by patient assessment. Criteria for appropriate prescribing were according to nationally accepted criteria outlined in the 1994-95 Antibiotic Guidelines handbook. All inpatients who were prescribed a third generation cephalosporin at Flinders Medical Centre for the duration of the audit period were eligible. This included medical, surgical, paediatric, obstetric and gynaecology inpatients.

RESULTS

Sixty-five per cent of prescriptions for third generation cephalosporins were judged appropriate, 31% inappropriate and 4% doubtful. Inappropriate use was found particularly in the treatment of respiratory tract infections and abdominal sepsis, and in surgical prophylactic use.

CONCLUSION

Third generation cephalosporin prescribing in a tertiary care teaching hospital is frequently inappropriate, as judged against widely available Australian guidelines.

Management of isolated systolic hypertension

Isolated systolic hypertension (ISH) [systolic blood pressure (SBP) > or = l60mm Hg with diastolic blood pressure (DBP) <90mm Hg] is the commonest form of hypertension in the elderly, and accounts for about 60% of all hypertensive conditions in the population aged over 65 years. It is associated with a significantly increased risk of cardiovascular and cerebrovascular morbidity and mortality. The landmark Systolic Hypertension in the Elderly Program (SHEP) study, published in 1991, has shown that lowering the SBP in elderly patients with ISH results in a significant reduction in cardiovascular events. These results have had a major impact on clinical practice in hypertension. On theoretical grounds, considering the pathophysiological mechanisms of ISH in the elderly, any drug which lowers total peripheral resistance and/or arterial stiffness should reduce SBP effectively in these patients. This effect has been observed in outcome studies and short term clinical trials using a variety of drugs from the 4 major antihypertensive classes: diuretics, beta(1)-blockers, calcium channel antagonists and ACE inhibitors. Other drugs, including alpha antagonists, may also be effective. In general, there is compelling evidence to support active treatment of any individual with an SBP > or = 160mm Hg. As in essential hypertension, the maximum benefit is gained by aggressive treatment of those individuals at highest risk because of coexisting cardiovascular risk factors. In these people, an SBP of 140 to 159mm Hg should be considered to be an indication for active management. Initial management should be by manipulation of lifestyle factors such as bodyweight, salt and alcohol intake and aerobic exercise. Drug therapy, generally well tolerated in low doses, should be considered if SBP remains > or = 160mm Hg, or > or = 140mm Hg in the presence of multiple risk factors. The choice of initial drug therapy should be influenced by the particular clinical situation. If there are no coexisting contraindications or co-indications for particular drugs, it is reasonable to begin treatment with a low dose of a thiazide-like diuretic, as used in the SHEP study. However, in short term treatment trials calcium channel antagonists and ACE inhibitors have been shown to lower SBP effectively and can be used in the appropriate clinical context. Beta-blockers appear to be less effective as monotherapy in ISH. Combination therapy is frequently required and can be effective and well tolerated if carefully chosen.

Diagnosis and classification in autism

This study compared four systems for the diagnosis of autism (DSM-III, DSM-III-R, DSM-IV, and ICD-10) with two empirically derived taxa of autism, and with three social subgroups of autism (Aloof, Passive, and Active-but-Odd) in 194 preschool children with salient social impairment. There were significant behavior and IQ differences between autistic and other-PDD groups for all four diagnostic systems, and a significant association was found (a) for Taxon B, diagnoses of autism, and the Aloof subgroup, and (b) for Taxon A, other-PDD, and the Active-but-Odd subgroup. Findings offer support for two major overlapping continua within idiopathic Pervasive Developmental Disorder.

The recognition of autism in children with Down syndrome--implications for intervention and some speculations about pathology

Although autism can occur in conjunction with a range of other conditions, the association with Down syndrome is generally considered to be relatively rare. Four young boys with Down syndrome are described who were also autistic. All children clearly fulfilled the diagnostic criteria for autism required by the ICD-10 or DSM-III-R, but in each case the parents had faced considerable difficulties in obtaining this diagnosis. Instead, the children's problems had been attributed to their cognitive delays, despite the fact that their behaviour and general progress differed from other children with Down syndrome in many important aspects. The implications, for both families and children, of the failure to diagnose autism when it co-occurs with other conditions such as Down syndrome are discussed. Some speculations about possible pathological associations are also presented.

Pervasive developmental disorders: from DSM-III to DSM-III-R

The present paper provides a brief history of the development of the DSM-III-R (American Psychiatric Association [APA], 1987) section on Pervasive Developmental Disorders. It describes the process by which the contents of the text and criteria for Autistic Disorder and Pervasive Developmental Disorder Not Otherwise Specified were decided and gives the reasons for the changes from DSM-III (APA, 1980) categories and criteria. The paper concludes with a short discussion of critical diagnostic issues.

Aging and susceptibility to drug-induced orthostatic hypotension

OBJECTIVE

To test the hypothesis that the short-term effect of transbuccal nitroglycerin (glyceryl trinitrate, 0.0625 to 1.5 mg) on orthostatic cardiovascular responses would predict the effect of a diuretic (5 mg bendroflumethiazide daily for 1 week), particularly in elderly subjects who may be at higher risk for orthostatic hypotension.

METHODS

This was a randomized crossover study. Participants were 17 elderly (age range, 63 to 84 years) and 15 younger (age range, 19 to 35 years) healthy ambulant volunteers. Interventions and measures of outcome included blood pressure (BP; in millimeters of mercury) and heart rate (HR; in beats per minute) changes with standing, which were measured before administration of medication and after each drug treatment.

RESULTS

Subjects in the elderly and younger groups had different BP and HR changes (mean percentage change) at 1 minute after standing in all three study phases (unmedicated, elderly: BP, -4%/+1%; HR, +12%; young: BP, +2%/+12%; HR, +27%; p = 0.06 for BP, p less than 0.01 for HR; bendroflumethiazide, elderly: BP, -9%/-3%; HR, +17%; young: BP, +1%/+11%; HR, +33%; p less than 0.05 for all; nitroglycerin (0.25 mg), elderly: BP, -15%/-12%; HR, +21%; young: BP, -6%/+7%; HR, +38%; p less than 0.05 for all). The incremental orthostatic effects of the two drugs were similar in the two age groups and were positively correlated (r = 0.65, p less than 0.001) in individual subjects.

CONCLUSIONS

Individual susceptibility to drug-induced orthostatic hypotension depends on a combination of the age-related unmedicated orthostatic response and the additional drug effect, which is independent of age. The BP response to standing after administration of nitroglycerin may be useful in predicting the effect of other drugs known to influence orthostatic BP control.

Analysis of time trends, individual subject responses and background variation in crossover factorial studies with antihypertensive drugs

In studying patients with mild hypertension, we used a double-blind, randomly allocated crossover, 2 x 2 factorial design to obtain more precise estimates of the effectiveness of individual hypertensive drugs and of the interactions when used in combination. In the present study, we reanalysed data from our own previously completed crossover factorial studies in order to determine the optimal length of phases and to try to exploit patient heterogeneity by comparing blood pressure responses within each patient to the two different drugs in each study. An analysis of the 'weeks within phases' variation (analysis of variance) applied to all phases, to the placebo phases alone and to the active treatment phases alone, of the individual factorial studies and of pooled data from studies of similar design, only revealed differences in the first week of our 4-week phases. Accordingly, we suggest that 4 weeks is an optimal phase length, since only the values from the third and fourth weeks showed the full expression of a drug's antihypertensive effect, avoiding the problem of a carryover effect and the need for a more complex intervening washout placebo phase. Comparing the blood pressure reductions shown by individual patients in response to different antihypertensive drugs using arbitrary criteria of greater than or equal to 5, 10 and 15 mmHg for diastolic and greater than or equal to 5, 10 and 20 mmHg for systolic pressure, we were unable to distinguish between the two separate drugs in each factorial study, due to the magnitude of the background variation which had a coefficient of variation of 5-7%.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuropeptide Y in the sympathetic control of blood pressure in hypertensive subjects

Neuropeptide Y (NPY) coexists with noradrenaline in postganglionic sympathetic neurons and with noradrenaline and adrenaline in the central nervous system. The possibility that NPY is released into the circulation during activation of the sympathoadrenal system was investigated in ten moderately hypertensive volunteers using three different stimuli. In healthy moderately hypertensive volunteers cold pressor test, head up tilt and graded bicycle exercise resulted in increased blood pressure, heart rate and plasma catecholamine concentrations. While there was a trend for plasma NPY-like immunoreactivity (NPY-LI) to increase during cold pressor test and head up tilt, NPY-LI concentration only increased significantly during bicycle exercise, the stimulus of greatest duration. These results suggest that plasma NPY-LI can be released into the circulation on sympathoadrenal activation in moderately hypertensive subjects and demonstrate that the pattern of release is similar to that previously observed in normotensive subjects.

Sleep problems in handicapped children: a preliminary study

Data are reported from an exploratory study looking at the prevalence of sleep problems (broken sleep and limited hours of sleep) in a population of handicapped children. Some degree of difficulty occurred in over a third of the population. There were strong associations with age, a range of serious daytime behavioural difficulties and indices of family stress. Some support for distinct subgroups (night waking, limited hours) was obtained. The implications of these findings are discussed.

Identical triplets with Asperger's syndrome

The case histories are presented of three 17 year old identical male triplets with Asperger's syndrome. They show the impairments affecting social interaction, non-verbal communication and imagination, the motor clumsiness, and the circumscribed interests characteristic of that condition. They also have some features in their history and present behaviour more typical of childhood autism. Despite marked overall similarities, the three differ in the severity with which their problems are manifested. A relationship can be found between the amount of peri- and post-natal trauma, degree of intellectual impairment and number of autistic features. The findings support the hypothesis that autism and Asperger's syndrome are on the same continuum of pathology.

The Disability Assessment Schedule: a brief screening device for use with the mentally retarded

Various types of reliability measures were conducted on the Disability Assessment Schedule, a structured interview devised to elicit from parents or care staff details of impairments, skills and behaviour problems in mentally retarded children and adults. The results indicated high overall agreement when the schedule was repeated over time, and also when used by several trained interviewers to rate the same interview. Problems arising from the use of such interview schedules are discussed, and suggestions are made for improving the design and method of administration.

Prevalence of autism and related conditions in adults in a mental handicap hospital

The proportions of subjects with severe social impairment and those retaining the features of childhood autism were investigated in a population of mentally retarded adults in a long-stay hospital. The results confirmed the findings of an earlier study of mentally retarded children (Wing & Gould, 1979) that the administrative category of mental retardation includes a substantial minority of people with severe impairment of two-way social interaction. Such social impairment occurred in 38% of the adult population and was very significantly associated with abnormalities of communication and imaginative activities. Muteness, repetitive stereotyped behaviour, including repetitive speech, and a range of behaviour problems also occurred more frequently in the socially impaired group. Two methods of sub-classifying the socially impaired were compared. Classification based on the severity of social impairment gave more statistically significant associations with behavioural and psychological variables than did a method based on the presence or absence of typical autism. The implications of these findings and their relevance for management and planning of services for the mentally retarded were briefly discussed.

Sex ratios in early childhood autism and related conditions

Children aged 0-14 on a specified census day, with impairments of verbal and nonverbal communication, social interaction and imaginative play, and with repetitive, stereotyped activities, were identified in an epidemiological study carried out in an area of southeast London. Sociable moderately, severely, and profoundly retarded children were included for comparison. An overall male:female ratio of 2.6:1 was found in those with language and social impairments, but, in the children of this group who were moderately, severely, or profoundly retarded, the ratio was 2.1:1, closely similar to that found in children in the same IQ range with Down's syndrome or cerebral palsy. The excess of males was much more marked in language and socially impaired children who were of higher ability, or who had a history of typical early childhood autism. The findings were linked to hypotheses of genetically greater variability in males, and to male-female differences in visuo-spatial and language skills.

Language, social, and cognitive impairments in autism and severe mental retardation

An epidemiological study is outlined that shows that Kanner's syndrome is one group among a wider range of children, all with impairment of social interaction, communication, and imagination. Most, but not all, children with this triad of impairments are severely mentally retarded, although severe retardation also occurs in those who are sociable and communicative. It is hypothesized that the socially impaired lack certain abilities that are inborn in normal children and the sociable mentally retarded: namely, the capacity to produce and monitor the normal species-specific preverbal sounds, the drive to explore the environment and form concepts to explain experiences, and the ability to recognize that other human beings are of special interest and importance. A possible neurological basis for these problems is briefly considered.

Asperger's syndrome: a clinical account

The clinical features, course, aetiology, epidemiology, differential diagnosis and management of Asperger's syndrome are described. Classification is discussed and reasons are given for including the syndrome, together with early childhood autism, in a wider group of conditions which have, in common, impairment of development of social interaction, communication and imagination.

Childhood autism and social class: a question of selection?

Children with typical autism, other early childhood psychoses and severe mental retardation without autistic behaviour were identified in an epidemiological study in an area of South East London. The social class distribution of their fathers was examined and no significant differences were found between the groups, nor in a comparison with the general population of the area. Fathers of children with autism and related conditions referred to an out-patient clinic with a special interest in autism, mostly at their own request, and fathers joining the National Society for Autistic Children, were of higher social class than both the average for England and Wales and the fathers of the study children. Joining the NSAC during its early years, and keeping up membership were also linked with higher social class. The findings supported the view that reports of a social class bias in autism may be explained by factors affecting referral and diagnosis.

Severe impairments of social interaction and associated abnormalities in children: epidemiology and classification

The prevalence, in children aged under 15, of severe impairments of social interaction, language abnormalities, and repetitive stereotyped behaviors was investigated in an area of London. A "socially impaired" group (more than half of whom were severely retarded) and a comparison group of "sociable severely mentally retarded" children were identified. Mutism or echolalia, and repetitive stereotyped behaviors were found in almost all the socially impaired children, but to a less marked extent in a minority of the sociable severely retarded. Certain organic conditions were found more often in the socially impaired group. A subgroup with a history of Kanner's early childhood autism could be identified reliably but shared many abnormalities with other socially impaired children. The relationships between mental retardation, typical autism, and other conditions involving social impairment were discussed, and a system of classification based on quality of social interaction was considered.