Is there an increase in the prevalence of autism spectrum disorders?

This report summarizes recent prevalence estimates for autism spectrum disorders and outlines possible reasons for an apparent increase in the numbers of children diagnosed with autism and Asperger syndrome.

Effect of bacterial endotoxin and middle ear effusion on ciliary activity: implications for otitis media

OBJECTIVES/HYPOTHESIS

Otitis media with effusion (OME) is the most common cause of childhood deafness. The pathogenesis is not fully understood, especially the reasons for failure of mucociliary clearance of the middle ear. It is not clear whether the cilia function normally in the middle ear and eustachian tube in the chronic phase of otitis media with effusion. However, impaired ciliary function in primary ciliary dyskinesia is known to be frequently associated with the development of otitis media with effusion. We hypothesized that endotoxin or the bacterial products in middle ear fluid in otitis media with effusion would adversely affect ciliary activity, thereby contributing to the pathogenesis of the disease.

STUDY DESIGN

Laboratory-based study of human ciliary activity with reference to otitis media with effusion.

METHODS

We have studied the activity of human adenoidal cilia under various conditions. Ciliary activity in the presence of Haemophilus influenzae endotoxin additions (at varying concentrations) to cultured adenoidal explants has been measured. In addition, ciliary activity of these explants was also observed after addition of middle ear effusion aspirated from patients.

RESULTS

We have shown that endotoxin in concentrations far in excess of those found in the middle ear with chronic otitis media with effusion had no effect on ciliary activity. Furthermore, ciliary activity was completely unaffected by the presence of middle ear effusion.

CONCLUSION

There is no evidence that ciliary activity is reduced by the constituents of middle ear fluid in chronic otitis media with effusion.

Evaluation of a community intervention programme for preschool behaviour problems

OBJECTIVES

To evaluate an early intervention project focused on improving child prereading skills and parent behaviour-management skills, for 4-year-old children in the western suburbs of Melbourne (Victoria, Australia).

METHODOLOGY

Following screening of a large sample of preschoolers, four groups were constructed: (i) children receiving a phonological skills-based prereading package in their normal preschool programme; (ii) children whose parents attended six sessions of child behaviour management skill training; (iii) children who received both interventions; and (iv) a control group. Pre-, post-, 1 and 2 year follow-up measures were taken to assess effects on child behavioural and learning adjustment.

RESULTS AND CONCLUSIONS

This community based intervention resulted in positive effects, despite being of low intensity, in achieving significantly less hyperactive/distractable behaviour in children from the combined intervention group at 2 years postintervention. Anxiety problems were also reduced at the post-treatment phase. The prereading package did not demonstrate any effects on reading skills and was deemed to be insufficiently intensive to affect a population of disadvantaged preschoolers. This universal-type of intervention was well accepted by the community, but there is need for further effort to increase recruitment of families of at-risk children into such programmes.

Biochemical risk factors for cardiovascular disease in an aged male population: emerging vascular pathogens

The progressive increase of deaths and morbidity from cardiovascular disease (CVD) in most developed societies has led to the formulation of preventive strategies and application of several diagnostic guidelines. However, there is emerging evidence that most panels and algorithms are inadequate and require urgent revision and updating. Therefore, the aim of this study was the evaluation of a wide cardiovascular risk profile in elderly male patients with acute myocardial infarction (AMI) or peripheral occlusive disease (POD). The risk profile was assessed by measuring conventional serum lipid and lipoprotein levels and emerging parameters: lipoprotein(a) (Lp[a]), homocysteine (Hcy), and C-reactive protein (CRP). The concentration of triglycerides, Lp(a), Hcy and the total cholesterol/high-density lipoprotein (TC/HDL) ratio were significantly higher in both classes of patients than in a population of matched healthy controls and, similarly, patients with CVD displayed lower plasma values of HDL. No significant differences were observed for TC, low-density lipoprotein (LDL), and CRP. Patients with POD exhibited a marked atherogenic profile, as attested by substantially increased values of Hcy, Lp(a), triglycerides, and TC/HDL ratio. The frequency distributions of Lp(a) and Hcy concentrations were markedly shifted toward upper values in both classes of patients than in controls. In multivariate regression analysis, Lp(a) and Hcy were the best predictors for AMI, whereas Lp(a), Hcy, and the TC/HDL ratio were the best predictors for POD. Taken together, these data suggest that Lp(a) and Hcy excesses might exert a central role in the development of atherosclerotic disease in elderly male patients. Thereby, the inclusion of those tests, along with the TC/HDL ratio and other more conventional analyses in panels for the evaluation of the cardiovascular risk might be profitable in terms of effectual prevention.

Redundancy gain in the stop-signal paradigm: implications for the locus of coactivation in simple reaction time

The authors carried out 2 experiments designed to cast light on the locus of redundancy gain in simple visual reaction time by using a stop-signal paradigm. In Experiment 1, the authors found that single visual stimuli were more easily inhibited than double visual stimuli by an acoustic stop signal. This result is in keeping with the idea that redundancy gain occurs prior to the ballistic stage of the stop-signal task. In Experiment 2, the authors found that the response to an acoustic go signal was more easily inhibited by a double than by a single visual stop signal. This result provides conclusive evidence for a redundancy gain in the stop process--in a process that does not involve a motor response but rather its inhibition.

Vascular adhesion molecule-1 and markers of platelet function before and after a treatment with iloprost or a supervised physical exercise program in patients with peripheral arterial disease

Platelet function and levels of vascular adhesion molecule-1 (VCAM-1) were investigated in 24 patients with peripheral arterial disease at Fontaine stage II undergoing a 2 weeks treatment with iloprost (0.5-2 ng/kg/h i.v. infused, 6 h/day) or a 2 weeks supervised physical training, randomly assigned. Patients were studied before (T0) and after (T14) treatments and 10 days later (T24). The adhesion of washed platelets to fibrinogen coated microwells was reduced after treatment both with iloprost (1.9+/-0.4 vs 6.8+/-0.7%; T24 vs T0; M+/-SEM; p<0.05) and physical exercise (3.0+/-1.0 vs 6.7+/-0.7; p<0.05) while adhesion to human plasma coated microwells was reduced only after treatment with iloprost (1.9+/-0.8 vs 5.8+/-0.9; p<0.05). The expression of fibrinogen receptor (glycoprotein IIb/IIIa) on platelets, measured by flow-cytometry was also reduced after iloprost treatment (17.1+/-1.5 vs 31.8+/-4.8 AU; p<0.05) and physical exercise (14.6+/-1.5 vs 34.0+/-3.3; p<0.05). Theurinaryexcretion of platelet thromboxane A2 metabolite 2,3-dinor-thromboxane B2 decreased only in patients treated with iloprost (154.7+/-97.9 vs 256.2+/-106.4 pg mg creatinine(-1); p<0.05). Similarly plasma VCAM-1 was lower in patients who were treated with iloprost (827.7+/-77.4 vs 999.0+/-83.8 ng ml(-1); p<0.05). In conclusion, both iloprost and physical exercise seem to act on reversible phenomena such as the expression of adhesion molecules or ex vivo adhesion, whereas only iloprost reduces thromboxane A2 biosynthesis in vivo. This anti-platelet activity seems to be extended in time and to be associated with an improvement in vascular function.

Longitudinal predictors of behavioural adjustment in pre-adolescent children

OBJECTIVES

Longitudinal data from infancy onwards, from the Australian Temperament Project, a prospective study of the temperament and development of a large and representative sample of Victorian children, were examined to identify predictors of psychological disorder at 11-12 years of age.

METHOD

Those children scoring in the at-risk range for psychological disorder according to parents, teachers and self-reports using the Child Behaviour Questionnaire were selected at 11-12 years of age for in-depth assessment and comparison with a group of children with no history of adjustment problems. Analyses of group differences using longitudinal data gathered from infancy to 12 years focused on parent and teacher reports on child temperament and behaviour, and various facets of home and school adjustment.

RESULTS

The strongest predictors of adjustment at 12 years were previous behaviour problems, along with some specific temperament factors involving self-regulation capacities and mother's overall rating of child difficulty. Results based on parallel teacher data including peer adjustment, and social and academic competence measures were consistent with parent data.

CONCLUSIONS

Our research confirms the persistence of early appearing behaviour problems in a community sample and the longitudinal influence of temperament factors in childhood. The study supports the need for a focus on early intervention and prevention strategies in the child mental health field.

Association of a polymorphism of the dopamine transporter gene with externalizing behavior problems and associated temperament traits: a longitudinal study from infancy to the mid-teens

There have been reports that a variable number of tandem repeats (VNTR) polymorphism situated in the 3' untranslated region of the dopamine transporter gene is associated with attention-deficit hyperactivity disorder. On the basis of these findings, we predicted an association of this polymorphism with hyperactivity, other externalizing behavior problems, and related temperament traits in a general population sample. The association was investigated using children participating in a longitudinal study of childhood temperament and development. DNA was taken from 660 children who had been assessed for temperament from 4-8 months to 15-16 years, and for behavior problems from 3-4 to 15-16 years. No significant associations were found at any age. There are a number of methodological differences from earlier studies that might explain the lack of associations with hyperactivity. It is also possible that the earlier findings are not replicable.

Poisoning with the recreational drug paramethoxyamphetamine ("death")

OBJECTIVE

To describe the clinical features of paramethoxyamphetamine (PMA; "death") poisoning and to compare these with those of people with self-reported "ecstasy" poisoning.

DESIGN

Retrospective casenote review.

PARTICIPANTS AND SETTING

22 patients who presented to the Emergency Department of the Royal Adelaide Hospital (RAH), a major metropolitan teaching hospital, between 1 January 1996 and 31 December 1998 with PMA poisoning identified through urine drug screens; and 61 patients with self-reported ecstasy poisoning between 1 September 1997 and 31 December 1998 found through the hospital databases.

RESULTS

Patients with PMA poisoning presented with tachycardia (64%), hyperthermia (temperature > 37.5 degrees C; 36%), coma (41%), seizures (32%), arrhythmias (23%), and QRS intervals > or = 100 ms (50%) with greater frequency and often greater severity than those with self-reported ecstasy poisoning. Two patients with PMA poisoning presented with severe hypoglycaemia (blood glucose level, < 1.5 mmol/L) accompanied by hyperkalaemia (K+ concentration, > 7.5 mmol/L).

CONCLUSIONS

At our hospital, PMA poisonings accounted for most of the severe reactions among people who believed they had taken ecstasy. Hypoglycaemia and hyperkalaemia may be specific to PMA poisoning. PMA toxicity should be suspected with severe or atypical reactions to "ecstasy", and confirmed by chromatographic urine drug screens.

Atomic dynamics in single and multi-photon double ionization: An experimental comparison

We have used a multi-particle imaging technique (COLTRIMS) to observe the double ionization of rare gas atoms by multi-photon absorption of 800 nm (1.5 eV) femto-second laser pulses and by single photon absorption (synchrotron radiation). Both processes are mediated by electron correlation. We discuss similarities and differences in the three-body final state momentum distributions.

MRI studies of the neurotoxic effects of l -2-chloropropionic acid on rat brain

L-2-Chloropropionic acid (L-CPA) is selectively toxic to rat cerebellar granule cells; necrosis is first observed about 36 hours after administration of L-CPA (750 mg/kg p.o.) becoming more marked by 48 h. Parallel to the onset of cell death an increase in cerebellar water content and sodium concentration has been reported suggesting an oedematous reaction. In this study T(2)-weighted (T(2)WI) and diffusion weighted (DWI) imaging were used to detect the development of neuronal damage in the cerebellum of rats as a result of exposure to L-CPA. T(2)WI and DWI were not able to detect cerebellar abnormalities at 37 h post-dosing except for a slight swelling of the cerebellum. However, at 48 h post-dosing when cerebellar swelling and granule cell necrosis were marked, T(2)WI and DWI hyperintensities were observed in the cerebellum. Therefore, under the conditions of this study, MRI was not able to detect abnormalities in the cerebellum prior to the onset of the clinical signs of neurotoxicity or at the time of early histological changes. T(2)WI also suggested a marked increase in the amount of fluid in the ventricular system of rats 37 and 48 h after dosing; fluid accumulation was observed in all animals studied whether or not necrosis was detected. The occurrence of T(2)WI hyperintensity in the forebrain lead us to discover a new lesion in the habenular nucleus.

Do executive function deficits differentiate between adolescents with ADHD and oppositional defiant/conduct disorder? A neuropsychological study using the Six Elements Test and Hayling Sentence Completion Test

Two neuropsychological measures of executive functions--Six Elements Tests (SET) and Hayling Sentence Completion Test (HSCT)--were administered to 110 adolescents, aged 12-15 years. Participants comprised four groups: Attention Deficit Hyperactivity Disorder (ADHD) only (n = 35). ADHD and Oppositional Defiant Disorder/Conduct Disorder (ODD/CD) (n = 38), ODD/CD only (n = 11), and a normal community control group (n = 26). Results indicated that adolescents with ADHD performed significantly worse on both the SET and HSCT than those without ADHD, whether or not they also had ODD/CD. The adolescents with ADHD and with comorbid ADHD and ODD/CD were significantly more impaired in their ability to generate strategies and to monitor their ongoing behavior compared with age-matched controls and adolescents with ODD/CD only. It is argued that among adolescents with clinically significant levels of externalizing behavior problems, executive function deficits are specific to those with ADHD. The findings support the sensitivity of these two relatively new tests of executive functions and their ecological validity in tapping into everyday situations, which are potentially problematic for individuals with ADHD.

Association of a functional polymorphism of the serotonin transporter gene with anxiety-related temperament and behavior problems in children: a longitudinal study from infancy to the mid-teens

A polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) has been associated with anxiety-related personality traits in adults. Initial studies showed that the short allele was associated with higher neuroticism, anxiety and harm avoidance. However, most attempts to replicate these findings have been negative. Because the association of candidate polymorphisms with behavioral traits may vary with stage of development, we investigated the association using participants in a longitudinal study of childhood temperament. DNA was available for 660 children who had been assessed for temperament from 4-8 months to 15-16 years, and for behaviour problems from 3-4 years to 15-16 years. No significant associations were found at most ages. However, at ages 13-14 years and 15-16 years, the long/long genotype was associated with higher anxiety. These findings do not support an association of the short allele with anxiety-related traits in early life.

Does shy-inhibited temperament in childhood lead to anxiety problems in adolescence?

OBJECTIVE

To assess the relationships between shy-inhibited temperament in childhood and anxiety problems in early adolescence using a prospective, longitudinal data set from a large community sample.

METHOD

Relationships between shyness ratings on age-appropriate temperament scales and anxiety problems were analyzed, looking both forward and backward in time from infancy to adolescence.

RESULTS

Forty-two percent of children rated as shy on 6 or more occasions over 8 surveys in childhood had anxiety problems in adolescence, compared with 11% who were never shy. Persistence of shyness and its presence in middle childhood increased risk for anxiety. A highly reactive temperament added to shyness did not increase the risk for anxiety. Few children with an anxiety diagnosis in early adolescence had a history of shyness.

CONCLUSIONS

Prediction from childhood shyness to adolescent anxiety disorder is modest but clinically meaningful in a community sample. However, most shy children did not develop an anxiety disorder and most adolescents with anxiety disorders had not been especially shy.

Activity of cardiopulmonary baroreceptors, peripheral resistance and cutaneous microcirculation in patients with peripheral obstructive arterial disease

OBJECTIVES

To assess the effects of cardiopulmonary baroreceptors on the haemodynamics of the humeral and common carotid arteries in patients suffering from peripheral artery disease (PAD) and to discover whether the stimulation of these receptors modifies the cutaneous microcirculation in the forearm.

DESIGN

We studied a group of patients suffering from peripheral artery disease and two groups as controls.

SETTING

Patients were examined at the ambulatory for Vascular Research, Division of Vascular Medicine and Rehabilitation, University of Verona.

PATIENTS

We studied 15 patients with peripheral artery disease of the lower limbs at Fontaine stage II (group C), 10 free of arterial pathologies (group B) and 10 young people (group A).

MAIN OUTCOME MEASURES

We subjected the patients to passive elevation of the legs and the trunk in a horizontal position with pressure monitoring and measurement of the calibre and flow in the brachial and common carotid arteries using a colourDoppler ultrasound. We also studied the cutaneous microcirculation with laserDoppler flowmetry.

RESULTS

During the test, arterial pressure and cardiac frequency remained constant in group A, systolic pressure values showed a slight, but statistically significant increase in group B, whilst the increase in systolic pressure values at this stage was marked in group C. Diastolic pressure values and cardiac frequency remained unchanged in all groups. The calibre of the humeral artery increased in the control groups. Carotid resistance was unchanged in the three groups. Humeral resistance during the test decreased in the two control groups whilst it increased in group C. The number of perfusion units felt in the control groups; no variations in group C.

CONCLUSIONS

Our study demonstrates, in patients with peripheral artery disease, a reduction in the activity of the cardiopulmonary baroreceptors with an increase in the humeral resistance during the test and impairment of the mechanisms of cutaneous microcirculatory vasoregulation in the forearm.

A longitudinal study of the role of childhood temperament in the later development of eating concerns

OBJECTIVE

This study examined the relationship between childhood temperament and the later development of eating and body concerns in early adolescent children.

METHOD

The Australian Temperament Project has followed a cohort of children from birth, assessing temperament factors such as Negative Emotionality, Persistence, Approach/Withdrawal, and Activity. Using a longitudinal design, the study reports on the relationship between temperament measured from infancy onward and eating and body concerns at 12-13 years of age. Participants (597 girls, 631 boys) completed the Eating Disorders Inventory subscales Drive For Thinness, Body Dissatisfaction, and Bulimia, and an estimate of their current size. Parents described their child's temperament and body size.

RESULTS

High Negative Emotionality and low Persistence were the factors most associated with risk status over time, particularly in girls.

DISCUSSION

While it is unlikely that temperamental characteristics per se lead to disordered eating, it is argued that in combination with other risk factors, certain temperamental characteristics may increase vulnerability.

Prevalence and characteristics of escape rhythms after radiofrequency ablation of the atrioventricular junction: results from the registry for AV junction ablation and pacing in atrial fibrillation. Ablate and Pace Trial Investigators

BACKGROUND

Radiofrequency ablation of the atrioventricular junction is a well-established procedure for the management of atrial fibrillation refractory to medical therapy. However, there are few data available on the prevalence and characteristics of the escape rhythms that are present after the procedure.

METHODS

The Ablate and Pace Trial was a prospective, multicenter registry of atrioventricular junction ablation and pacing in atrial fibrillation. Ablation of the atrioventricular junction was accomplished with radiofrequency energy with standard techniques. Before discharge from the hospital, patients underwent a systematic analysis of the rate and morphologic features of the escape rhythm, if any, that was present when the pacing rate was gradually decreased.

RESULTS

There were 156 patients from 16 centers who underwent attempted radiofrequency ablation of the atrioventricular junction. The procedure was successful in 155 (99%) of 156 patients. An escape rhythm was present in 104 patients (67%) after radiofrequency ablation. The escape rate ranged from 11 to 65 beats/min (mean 39 +/- 10 beats/min). Only 49 patients (31%) had an escape rate >/=40 beats/min. Of the 104 patients with an escape rhythm, 53 patients (51%) had a QRS that was unchanged from baseline. There was no correlation between the number of radiofrequency applications and the presence of an escape rhythm.

CONCLUSION

The majority of patients who undergo radiofrequency catheter ablation of the atrioventricular junction are pacemaker dependent after the procedure, as defined by lack of an escape rhythm or the presence of an escape rhythm that is <40 beats/min.

Psychological disorders and their correlates in an Australian community sample of preadolescent children

The nature and correlates of psychological disorders of preadolescent children from the longitudinal Australian Temperament Project (ATP) are reported. Almost half of the children identified via checklists completed by mothers, teachers, and the children themselves as being in the at-risk range for disorder received a DSM-III-R diagnosis. Nine per cent of comparison, or low-risk, children also received a diagnosis. Internalising disorders were the most common, and 44% of cases had multiple problems. Children rated as problematic by all three informants or by child plus teacher were the most likely to receive a diagnosis. The at-risk group had more difficult temperament, poorer family and peer relationships, lower levels of social skills, and were of lower SES than the comparison group. There were minimal differences on these variables between at-risk children who did, or did not, receive a DSM-III-R diagnosis. It is argued that especially for boys, checklists from multiple informants are effective tools for identifying clinically significant disorders.

[Endothelial function and the microcirculation in diabetes mellitus]

The role of endothelial dysfunction in the pathogenesis of diabetic microangiopathy is reviewed. Reversible alterations in microcirculation, consisting of increased capillary pressure, blood flow and endothelial permeability, can be detected at an early stage in diabetes mellitus. Irreversible structural modifications of the vascular wall, such as thickening of the basal membrane due to the extracellular accumulation of proteins, take place at later stages. Atherosclerosis further affects microcirculation in diabetes mellitus by decreasing autoregulatory capacity and blood flow reserve. Endothelial dysfunction has been observed to precede the onset of microvascular lesions, as demonstrated by reduction in the vasodilatory response to vasoactive agents and by alterations in the antithrombotic properties of the endothelium. Experimental data available so far suggest that endothelial dysfunction may be directly related to hyperglycemia. Abnormalities in lipoprotein metabolism, generation of glycation end products, and increased oxidative stress may also be responsible for the endothelial dysfunction in diabetes mellitus. Insulin resistance appears to be related to endothelial dysfunction in non-insulin-dependent diabetes mellitus through a reduction in the biological activity of endothelial-derived nitric oxide.

Relationships between learning difficulties and psychological problems in preadolescent children from a longitudinal sample

OBJECTIVES

To examine the relationships between learning difficulties and behavior problems in preadolescent children both concurrently and longitudinally, using data from the Australian Temperament Project, and to examine associations between DSM-diagnosed disorders and types of learning difficulties.

METHOD

Clinical and comparison groups of 11- to 12-year-old children were assessed on behavioral and learning indices and completed a structured diagnostic interview. Longitudinal data were available from earlier surveys of the development of these children.

RESULTS

Children in the clinical group were disadvantaged on all learning and behavioral indices, and their problems in many cases had been evident from 7 to 8 years of age. There were specific associations between types of learning difficulties and both internalizing and externalizing disorders. Numeracy difficulties were strongly associated with DSM diagnoses for both boys and girls, and externalizing problems tended to co-occur with a combination of learning problems.

CONCLUSIONS

Behavioral maladjustment in many domains is strongly associated with learning difficulties even after intelligence and socioeconomic factors are controlled. The odds ratios for persistence of difficulties throughout elementary school are extremely high for children with clinical problems.

The role of the family for behavioral outcome in children and adolescents following traumatic brain injury

This study assessed the behavioral outcome of 51 children with traumatic brain injury (TBI) up to 2 years following injury. Children with severe injuries, but not those with mild or moderate injuries, were reported by parents to have a greater incidence of behavior problems following TBI. Regression analyses indicated that the presence of a partner for the primary caregiver of the child and the acute emotional reaction of the parent to the injury were both predictive of child behavioral outcome, although not by 2-year follow-up. These findings suggest that parental coping resources may impact on the development of child behavioral sequelae following TBI, emphasizing the role of the family in the child's response and the importance of supportive intervention.

The role of the family for behavioral outcome in children and adolescents following traumatic brain injury

This study assessed the behavioral outcome of 51 children with traumatic brain injury (TBI) up to 2 years following injury. Children with severe injuries, but not those with mild or moderate injuries, were reported by parents to have a greater incidence of behavior problems following TBI. Regression analyses indicated that the presence of a partner for the primary caregiver of the child and the acute emotional reaction of the parent to the injury were both predictive of child behavioral outcome, although not by 2-year follow-up. These findings suggest that parental coping resources may impact on the development of child behavioral sequelae following TBI, emphasizing the role of the family in the child's response and the importance of supportive intervention.