Leptin excites basolateral amygdala principal neurons and reduces food intake by LepRb-JAK2-PI3K-dependent depression of GIRK channels

Leptin is an adipocyte-derived hormone that modulates food intake, energy balance, neuroendocrine status, thermogenesis, and cognition. Whereas a high density of leptin receptors has been detected in the basolateral amygdala (BLA) neurons, the physiological functions of leptin in the BLA have not been determined yet. We found that application of leptin excited BLA principal neurons by activation of the long form leptin receptor, LepRb. The LepRb-elicited excitation of BLA neurons was mediated by depression of the G protein-activated inwardly rectifying potassium (GIRK) channels. Janus Kinase 2 (JAK2) and phosphoinositide 3-kinase (PI3K) were required for leptin-induced excitation of BLA neurons and depression of GIRK channels. Microinjection of leptin into the BLA reduced food intake via activation of LepRb, JAK2, and PI3K. Our results may provide a cellular and molecular mechanism to explain the physiological roles of leptin in vivo.

Neuromedin B excites central lateral amygdala neurons and reduces cardiovascular output and fear-potentiated startle

Neuromedin B (NMB) and gastrin-releasing peptide (GRP) are the two mammalian analogs in the bombesin peptide family that exert a variety of actions including emotional processing, appetitive behaviors, cognition, and tumor growth. The bombesin-like peptides interact with three receptors: the NMB-preferring bombesin 1 (BB1) receptors, the GRP-preferring bombesin 2 (BB2) receptors and the orphan bombesin 3 (BB3) receptors. Whereas, injection of bombesin into the central amygdala reduces satiety and modulates blood pressure, the underlying cellular and molecular mechanisms have not been determined. As administration of bombesin induces the expression of Fos in the lateral nucleus of the central amygdala (CeL) which expresses BB1 receptors, we probed the effects of NMB on CeL neurons using in vitro and in vivo approaches. We showed that activation of the BB1 receptors increased action potential firing frequency recorded from CeL neurons via inhibition of the inwardly rectifying K+ (Kir) channels. Activities of phospholipase Cβ and protein kinase C were required, whereas intracellular Ca2+ release was unnecessary for BB1 receptor-elicited potentiation of neuronal excitability. Application of NMB directly into the CeA reduced blood pressure and heart rate and significantly reduced fear-potentiated startle. We may provide a cellular and molecular mechanism whereby bombesin-like peptides modulate anxiety and fear responses in the amygdala.

Ionic signalling mechanisms involved in neurokinin-3 receptor-mediated augmentation of fear-potentiated startle response in the basolateral amygdala

The tachykinin peptides include substance P (SP), neurokinin A and neurokinin B, which interact with three G-protein-coupled neurokinin receptors, NK1Rs, NK2Rs and NK3Rs, respectively. Whereas high densities of NK3Rs have been detected in the basolateral amygdala (BLA), the functions of NK3Rs in this brain region have not been determined. We found that activation of NK3Rs by application of the selective agonist, senktide, persistently excited BLA principal neurons. NK3R-elicited excitation of BLA neurons was mediated by activation of a non-selective cation channel and depression of the inwardly rectifying K+ (Kir) channels. With selective channel blockers and knockout mice, we further showed that NK3R activation excited BLA neurons by depressing the G protein-activated inwardly rectifying K+ (GIRK) channels and activating TRPC4 and TRPC5 channels. The effects of NK3Rs required the functions of phospholipase Cβ (PLCβ), but were independent of intracellular Ca2+ release and protein kinase C. PLCβ-mediated depletion of phosphatidylinositol 4,5-bisphosphate was involved in NK3R-induced excitation of BLA neurons. Microinjection of senktide into the BLA of rats augmented fear-potentiated startle (FPS) and this effect was blocked by prior injection of the selective NK3R antagonist SB 218795, suggesting that activation of NK3Rs in the BLA increased FPS. We further showed that TRPC4/5 and GIRK channels were involved in NK3R-elicited facilitation of FPS. Our results provide a cellular and molecular mechanism whereby NK3R activation excites BLA neurons and enhances FPS. KEY POINTS: Activation of NK3 receptors (NK3Rs) facilitates the excitability of principal neurons in rat basolateral amygdala (BLA). NK3R-induced excitation is mediated by inhibition of GIRK channels and activation of TRPC4/5 channels. Phospholipase Cβ and depletion of phosphatidylinositol 4,5-bisphosphate are necessary for NK3R-mediated excitation of BLA principal neurons. Activation of NK3Rs in the BLA facilitates fear-potentiated startle response. GIRK channels and TRPC4/5 channels are involved in NK3R-mediated augmentation of fear-potentiated startle.

Roles of PLCβ, PIP2 , and GIRK channels in arginine vasopressin-elicited excitation of CA1 pyramidal neurons

Arginine vasopressin (AVP) is a hormone exerting vasoconstrictive and antidiuretic action in the periphery and serves as a neuromodulator in the brain. Although the hippocampus receives vasopressinergic innervation and AVP has been shown to facilitate the excitability of CA1 pyramidal neurons, the involved ionic and signaling mechanisms have not been determined. Here we found that AVP excited CA1 pyramidal neurons by activation of V_1a receptors. Functions of G proteins and phospholipase Cβ (PLCβ) were required for AVP-elicited excitation of CA1 pyramidal neurons, whereas intracellular Ca²⁺ release and protein kinase C were unnecessary. PLCβ-mediated depletion of phosphatidylinositol 4,5-bisphosphate (PIP₂ ) was required for AVP-elicited excitation of CA1 pyramidal neurons. AVP augmented the input resistance and increased the time constants of CA1 pyramidal neurons. AVP induced an inward current in K⁺ -containing intracellular solution, whereas no inward currents were observed with Cs⁺ -containing intracellular solution. AVP-sensitive currents showed inward rectification with a reversal potential close to the K⁺ reversal potential, suggesting the involvement of inwardly rectifying K⁺ channels. AVP-induced currents were sensitive to the micromolar concentration of Ba²⁺ and tertiapin-Q, whereas application of ML 133, a selective Kir2 channel blocker had no effects, suggesting that AVP excited CA1 pyramidal neurons by depressing G protein-gated inwardly rectifying K⁺ channels. Activation of V_1a receptors in the CA1 region facilitated glutamatergic transmission onto subicular pyramidal neurons, suggesting that AVP modulates network activity in the brain. Our results may provide one of the cellular and molecular mechanisms to explain the in vivo physiological functions of AVP.

Involvement of TRPC5 channels, inwardly rectifying K+ channels, PLCβ and PIP2 in vasopressin-mediated excitation of medial central amygdala neurons

KEY POINTS

Activation of V_1a vasopressin receptors facilitates neuronal excitability in the medial nucleus of central amygdala (CeM) V_1a receptor activation excites about 80% CeM neurons by opening a cationic conductance and about 20% CeM neurons by suppressing an inwardly rectifying K⁺ (Kir) channel The cationic conductance activated by V_1a receptors is identified as TRPC5 channels PLCβ-mediated depletion of PIP₂ is involved in V_1a receptor-elicited excitation of CeM neurons Intracellular Ca²⁺ release and PKC are unnecessary for V_1a receptor-mediated excitation of CeM neurons ABSTRACT: Arginine vasopressin (AVP) serves as a hormone in the periphery to modulate water homeostasis and a neuromodulator in the brain to regulate a diverse range of functions including anxiety, social behaviour, cognitive activities and nociception. The amygdala is an essential brain region involved in modulating defensive and appetitive behaviours, pain and alcohol use disorders. Whereas activation of V_1a receptors in the medial nucleus of the central amygdala (CeM) increases neuronal excitability, the involved ionic and signalling mechanisms have not been determined. We found that activation of V_1a receptors in the CeM facilitated neuronal excitability predominantly by opening TRPC5 channels, although AVP excited about one fifth of the CeM neurons via suppressing an inwardly rectifying K⁺ (Kir) channel. G proteins and phospholipase Cβ (PLCβ) were required for AVP-elicited excitation of CeM neurons, whereas intracellular Ca²⁺ release and the activity of protein kinase C were unnecessary. Prevention of the depletion of phosphatidylinositol 4,5-bisphosphate (PIP₂ ) blocked AVP-induced excitation of CeM neurons, suggesting that PLCβ-mediated depletion of PIP₂ is involved in AVP-mediated excitation of CeM neurons. Our results may provide a cellular and molecular mechanism to explain the anxiogenic effects of AVP in the amygdala.

Activation of Oxytocin Receptors Excites Subicular Neurons by Multiple Signaling and Ionic Mechanisms

Oxytocin (OXT) is a nonapeptide that serves as a neuromodulator in the brain and a hormone participating in parturition and lactation in the periphery. The subiculum is the major output region of the hippocampus and an integral component in the networks that process sensory and motor cues to form a cognitive map encoding spatial, contextual, and emotional information. Whilst the subiculum expresses the highest OXT-binding sites and is the first brain region to be activated by peripheral application of OXT, the precise actions of OXT in the subiculum have not been determined. Our results demonstrate that application of the selective OXT receptor (OXTR) agonist, [Thr4,Gly7]-oxytocin (TGOT), excited subicular neurons via activation of TRPV1 channels, and depression of K+ channels. The OXTR-mediated excitation of subicular neurons required the functions of phospholipase Cβ, protein kinase C, and degradation of phosphatidylinositol 4,5-bisphosphate (PIP2). OXTR-elicited excitation of subicular neurons enhanced long-term potentiation via activation of TRPV1 channels. Our results provide a cellular and molecular mechanism to explain the physiological functions of OXT in the brain.

Oxytocin receptors excite lateral nucleus of central amygdala by phospholipase Cβ- and protein kinase C-dependent depression of inwardly rectifying K+ channels

KEY POINTS

Activation of oxytocin receptors (OXTRs) facilitates neuronal excitability in rat lateral nucleus of central amygdala (CeL). OXTR-induced excitation is mediated by inhibition of inwardly rectifying K⁺ (Kir) channels. Phospholipase Cβ is necessary for OXTR-mediated excitation of CeL neurons and depression of Kir channels. OXTR-elicited depression of Kir channels and excitation of CeL neurons require the function of Ca²⁺ -dependent protein kinase C.

ABSTRACT

Oxytocin (OXT) is a nonapeptide that exerts anxiolytic effects in the brain. The amygdala is an important structure involved in the modulation of fear and anxiety. A high density of OXT receptors (OXTRs) has been detected in the capsular (CeC) and lateral (CeL) nucleus of the central amygdala (CeA). Previous studies have demonstrated that activation of OXTRs induces remarkable increases in neuronal excitability in the CeL/C. However, the signalling and ionic mechanisms underlying OXTR-induced facilitation of neuronal excitability have not been determined. We found that activation of OXTRs in the CeL increased action potential firing frequency recorded from neurons in this region via inhibition of the inwardly rectifying K⁺ channels. The functions of phospholipase Cβ and protein kinase C were required for OXTR-induced augmentation of neuronal excitability. Our results provide a cellular and molecular mechanism whereby activation of OXTRs exerts anxiolytic effects.

Roles of K+ and cation channels in ORL-1 receptor-mediated depression of neuronal excitability and epileptic activities in the medial entorhinal cortex

Nociceptin (NOP) is an endogenous opioid-like peptide that selectively activates the opioid receptor-like (ORL-1) receptors. The entorhinal cortex (EC) is closely related to temporal lobe epilepsy and expresses high densities of ORL-1 receptors. However, the functions of NOP in the EC, especially in modulating the epileptiform activity in the EC, have not been determined. We demonstrated that activation of ORL-1 receptors remarkably inhibited the epileptiform activity in entorhinal slices induced by application of picrotoxin or by deprivation of extracellular Mg2+. NOP-mediated depression of epileptiform activity was independent of synaptic transmission in the EC, but mediated by inhibition of neuronal excitability in the EC. NOP hyperpolarized entorhinal neurons via activation of K+ channels and inhibition of cation channels. Whereas application of Ba2+ at 300 μM which is effective for the inward rectifier K+ (Kir) channels slightly inhibited NOP-induced hyperpolarization, the current-voltage (I-V) curve of the net currents induced by NOP was linear without showing inward rectification. However, a role of NOP-induced inhibition of cation channels was revealed after inhibition of Kir channels by Ba2+. Furthermore, NOP-mediated augmentation of membrane currents was differently affected by application of the blockers selective for distinct subfamilies of Kir channels. Whereas SCH23390 or ML133 blocked NOP-induced augmentation of membrane currents at negative potentials, application of tertiapin-Q exerted no actions on NOP-induced alteration of membrane currents. Our results demonstrated a novel cellular and molecular mechanism whereby activation of ORL-1 receptors depresses epilepsy.

Longitudinal Effects of Embryonic Exposure to Cocaine on Morphology, Cardiovascular Physiology, and Behavior in Zebrafish

A sizeable portion of the societal drain from cocaine abuse results from the complications of in utero drug exposure. Because of challenges in using humans and mammalian model organisms as test subjects, much debate remains about the impact of in utero cocaine exposure. Zebrafish offer a number of advantages as a model in longitudinal toxicology studies and are quite sensitive physiologically and behaviorally to cocaine. In this study, we have used zebrafish to model the effects of embryonic pre-exposure to cocaine on development and on subsequent cardiovascular physiology and cocaine-induced conditioned place preference (CPP) in longitudinal adults. Larval fish showed a progressive decrease in telencephalic size with increased doses of cocaine. These treated larvae also showed a dose dependent response in heart rate that persisted 24 h after drug cessation. Embryonic cocaine exposure had little effect on overall health of longitudinal adults, but subtle changes in cardiovascular physiology were seen including decreased sensitivity to isoproterenol and increased sensitivity to cocaine. These longitudinal adult fish also showed an embryonic dose-dependent change in CPP behavior, suggesting an increased sensitivity. These studies clearly show that pre-exposure during embryonic development affects subsequent cocaine sensitivity in longitudinal adults.

Dental anxiety levels in British servicemen and women

OBJECTIVES

The objectives of the study were to determine: 1, the level of dental anxiety in British Service personnel; 2 whether there was a difference in dental anxiety levels across the three Services; and, 3, the relationship between number of operational tours and level of dental anxiety.

BASIC RESEARCH DESIGN

Cross sectional questionnaire survey of individuals attending 3 Armed Services dental treatment centres in the UK. The questionnaires were completed between February 2008 and April 2009.

PARTICIPANTS

50 patients each from the Royal Navy, Army and Royal Air Force, selected consecutively from those attending the centres for treatment. There was a 100% response rate.

MAIN MEASURES

Dental fear as assessed by the Dental Fear Survey (DFS) and scores on a scale of fear of dental injections.

RESULTS

27% of the Armed Services experienced severe dental anxiety: a level similar to that found in the general population. There was no difference in the level of dental anxiety or fear of dental injections across the three Armed Services. There was no relationship between number of operational tours undertaken and level of dental anxiety.

CONCLUSIONS

Dental anxiety is found amongst members of the British Armed Services at levels similar to that in the general population. This represents a challenge for service provision, particularly in operational settings.

Summary of: compliance with pre-operative instructions for procedures with conscious sedation: a complete audit cycle

INTRODUCTION

A wide variety of procedures in all surgical departments are performed under conscious sedation with midazolam. Patients are required to adhere to a list of pre-operative instructions but poor compliance has been noted anecdotally in our department and in the literature. This can lead to delayed and cancelled appointments.

AIM

We aimed to audit the compliance of patients in following preoperative sedation instructions in the oral and maxillofacial department of a large tertiary teaching hospital with a view to improving compliance. All patients undergoing conscious sedation for day case procedures in a five month period were audited. We implemented changes based on findings and a literature review, followed by a second eight month period of audit.

RESULTS

Twenty-nine and 30 patients participated in each cycle respectively. In the first cycle over 55% of patients were non-compliant. The most common reasons were not bringing a competent adult escort at the start of the appointment (17% of total) and having consumed alcohol in the 24 hours pre-operatively (17%). Based on this, the patient information leaflet was revised. Patients received copies when being listed and then with their posted appointment letter, as well as being verbally reminded before attending. Second cycle results revealed a 22% increase in compliance rates across all instructions with all patients bringing competent escorts along.

CONCLUSIONS

Efficacy within the NHS is often achieved with simple and practical improvement to clinical and administrative practice. By achieving a reduction in non-compliance rates, the department was able to reduce appointment delays and waiting lists, ultimately to the patients' benefit.

Acceptability of behaviour therapy for dental phobia

OBJECTIVE

To determine how people with dental phobia rate the acceptability of behavioural therapy.

METHODS

One hundred and twenty individuals with dental phobia participated in a three-factor experimental vignette-based design. The three factors examined were dental treatment history, nature of intervention (intravenous sedation or behavioural therapy) and treatment outcome. There were eight different vignettes representing all combinations of the three experimental variables, and 15 participants completed each vignette.

RESULTS

Treatment outcome had a strong effect on rated acceptability (F = 115.76, P < 0.001). There was a weaker effect of treatment type (F = 5.49, P < 0.05) with behavioural therapy rated as more acceptable than intravenous sedation. Previous history of intravenous sedation was associated with a decreased perception that it is possible to overcome dental fear.

CONCLUSIONS

The perceptions of individuals with dental phobia of the acceptability of behavioural approaches to management are influenced by the perceived outcome of the treatment.

What happens after referral for sedation?

OBJECTIVE

To follow up 100 referrals to the sedation clinic, examining dental anxiety and background of patients, and to assess how many patients attended for treatment planning, initial treatment and how many completed treatment, and describe the characteristics of each. For those who attended for initial treatment, to investigate which type of sedation they received and the level of clinician they saw.

DESIGN

Descriptive, cross-sectional survey and review of case notes.

SUBJECTS AND METHODS

Subjects were 100 consecutive new patients to the Department of Sedation and Special Care Dentistry at Guy's and St Thomas NHS Foundation Trust. The notes were analysed by an experienced member of staff (CAB) and data entered into an Excel spreadsheet and an SPSS data file created. These data were merged with a dataset containing their responses to the initial questionnaire and medical history for analysis.

RESULTS

Of the 100 patients initially referred, 72 attended the treatment planning session, 66 of the 72 (92%) attended for initial dental treatment, and 33 of 66 (50%) completed treatment. Dental Fear Survey (DFS) scores were related to attendance at the initial treatment visit but not to completion of treatment. Only 33 of 100 referred patients completed treatment.

CONCLUSIONS

Attendance for treatment planning and initial treatment was high. Attendance is related to fear and mental health. Overall completion of treatment from referral was 33%.

Internal recycle to improve denitrification in a step feed anoxic/aerobic activated sludge system

During periods of low load (weekends and holidays) the Mangere wastewater treatment plant effluent has breached the summer consent conditions for total nitrogen. The purpose of this research was to determine if an internal recycle would improve nitrogen removal in the anoxic/aerobic activated sludge reactors sufficient to meet the summer resource consent standard. The recycle returned nitrate rich mixed liquor from the downstream aerobic zone back to the initial anoxic zone, thus potentially improving denitrification. A full scale trial showed that installation of the internal recycle on each RC would have satisfied the resource consent for total nitrogen in most cases over the three summer resource consent periods since the upgrade. However, further modifications of the internal recycle would be required to ensure that consent conditions were satisfied at all times and to improve the consistency of the results.

Conscious sedation training received by specialist registrars in restorative dentistry in the UK: a survey

OBJECTIVE

To investigate conscious sedation training received by Specialist Registrars in Restorative Dentistry (SpRs) during their training programme.

DESIGN

Postal questionnaire survey in the UK. Setting SpRs and recently certificated Consultants in Restorative Dentistry (CRDs).

METHOD

A questionnaire was sent to 81 current SpRs in Restorative Dentistry and CRDs who had been awarded a Certificate of Completion of Specialist Training within the previous three years. One follow-up letter was sent to non-responders.

RESULTS

The completed questionnaire was returned by 67 (83%) SpRs and CRDs. Analysis revealed that 44 (69%) respondents had received conscious sedation training during their specialist training programme and that 50 (78%) respondents carried out restorative dental treatment under sedation during their programme. Thirteen (20%) respondents had not received conscious sedation training in their programmes but eight (13%) SpRs indicated that sedation training was planned. Training experiences differed throughout the UK: 29 (66%) respondents gained experience in inhalational and single agent intravenous sedation techniques under the supervision of an experienced colleague. Fourteen (32%) respondents who performed sedation had not been on a resuscitation course in the previous year. These included nine (21%) current SpRs. Sixteen (53%) current SpRs intended to offer restorative dental treatment under sedation after specialist training. Fifty-nine (92%) respondents thought that all SpRs in Restorative Dentistry should receive sedation training and 42 (71%) thought that a structured core course would be the most appropriate format.

CONCLUSIONS

Although the majority of SpRs and recently certificated CRDs considered that all SpRs should receive training in conscious sedation via a core course during the restorative dentistry training programme, a small number had not received or planned to undertake such training. Conscious sedation training experiences differed throughout the UK and SpRs treated a wide range of deserving patient categories under sedation. It is encouraging that many SpRs hope to continue employing sedation techniques after their restorative dentistry training has finished. The results of this survey should inform all those involved with restorative dentistry training programmes.

Effectiveness in controlling haemorrhage after dental scaling in people with haemophilia by using tranexamic acid mouthwash

AIMS

To compare the effectiveness of tranexamic acid mouthwash (TAMW) in controlling gingival haemorrhage after dental scaling with that of using factor replacement therapy (FRT) prior to dental scaling in people with haemophilia.

DESIGN

Double-blind cross-over randomised control trial.

SETTING

Dedicated hospital dental practice for patients with inherited bleeding disorders.

METHOD

Sixteen patients with haemophilia who required dental scaling participated in this pilot study. The experimental treatment regime (ETR) involved transfusing each patient with saline before scaling both quadrants on one side of the mouth followed by oral rinsing with TAMW four times daily for up to eight days. The control regime (CR) involved giving each patient FRT before scaling the opposite side of the mouth followed by use of a placebo TAMW. Each patient underwent both treatments in a random-ised sequence. Both the operator and the patients were unaware of which were the ETR and CR episodes. On both occasions the patient kept a log book of the rinsing regime and any post-operative bleeding. Additionally, a structured post-treatment telephone interview was conducted to assess the effectiveness and the patient acceptability of the ETR.

RESULTS

Thirteen patients completed the study. No statistically significant difference was found in gingival bleeding and mouthwashing frequencies between the ETR and the CR (p > 0.05). Five patients reported no gingival bleeding with either the ETR or the CR. No patient, using either regime, required extra FRT due to gingival haemorrhage. All subjects found the ETR acceptable and easy and reported feeling safe in using TAMW alone to control gingival bleeding after dental scaling.

CONCLUSION

TAMW use after dental scaling was as effective as using FRT beforehand in controlling gingival haemorrhage for people with haemophilia.

Increased risk for developmental disabilities in children who have major birth defects: a population-based study

OBJECTIVE

We sought to quantify the strength of associations between each of four specific developmental disabilities (DDs) and specific types of major birth defects.

METHODS

We linked data from 2 independent surveillance systems, the Metropolitan Atlanta Congenital Defects Program and the Metropolitan Atlanta Developmental Disabilities Surveillance Program. Children with major birth defects (n = 9142; born 1981-1991 in metro Atlanta) and 3- to 10-year-old children who were born between 1981 and 1991 in metro Atlanta and identified between 1991 and 1994 as having mental retardation, cerebral palsy, hearing impairment, or vision impairment (n = 3685) were studied. Prevalence ratio (PR), which is the prevalence of a DD in children with 1 or more major birth defects divided by the prevalence of the same DD in children without major birth defects, was measured.

RESULTS

Among the 9142 children who were born with a major birth defect, 657 (7.2%) had a serious DD compared with 0.9% in children with no major birth defect, yielding a PR of 8.3 (95% confidence interval: 7.6-9.0). In general, the more severe the DD, the higher was the PR. Birth defects that originated in the nervous system and chromosomal defects resulted in the highest PRs for a subsequent DD. For all other categories of birth defects, PRs were lowest when all major birth defects present were confined to a single category (ie, isolated defects). PRs for any DD increased monotonically with the number of coded birth defects per child or the number of different birth defect categories per child, regardless of the severity of the defect or whether defects of the nervous system, chromosomal defects, or "other syndromes" were counted.

CONCLUSIONS

These data highlight the possible early prenatal origins of some DDs and suggest that both the number of coded birth defects present and the number of anatomic systems involved are strongly related to functional outcomes.

Contribution of sickle cell disease to the occurrence of developmental disabilities: a population-based study

PURPOSE

Population-based surveillance of children aged 3-10 years from metropolitan Atlanta was used to determine if stroke-related neurological damage in children with sickle cell disease (SCD) is associated with developmental disabilities (DD).

METHODS

School and medical records were reviewed annually to identify eligible children. Observed-to-expected ratios, P values, and population attributable fractions were calculated.

RESULTS

Children with SCD had increased risk for DD (O/E = 3.2, P < 0.0001), particularly mental retardation (O/E = 2.7, P = 0.0005) and cerebral palsy (O/E = 10.8, P < 0.0001). This risk was confined to DD associated with stroke (O/E = 130, P < 0.0001; for DD without stroke: O/E = 1.3, P = 0.23).

CONCLUSIONS

Children with SCD have increased risk for DD associated with stroke; thus, aggressive interventions are needed to prevent stroke in these children.

Multiple Stafne bone cavities: a diagnostic dilemma

Salivary gland inclusions in the mandible are relatively uncommon. If defects occur they are generally unilateral, although bilateral cases have been reported. This article describes an unusual case in which the dental panoramic tomogram revealed three radiolucent areas in the mandible. The diagnosis of the two posterior radiolucencies was confirmed as Stafne's bone cavities but a definite diagnosis for the parasymphyseal lesion remained elusive, even after surgery. However, Stafne's bone cavities are known to occur in this region and this diagnosis remains the most probable.

A sedation technique for implant and periodontal surgery

OBJECTIVE

Evaluation of a sedation technique which involved titrating intravenous midazolam to an 'ideal' sedation end point, followed by a continuous infusion of propofol. This technique might be a satisfactory alternative to general anaesthesia for implant surgery in anxious patients or when procedures exceed 60-min duration.

MATERIAL AND METHODS

20 patients were treated on 23 occasions. A 2-mg bolus of midazolam was injected intravenously followed after 90 s by 1 mg increments until the patient was adequately sedated. 30 min after this induction with midazolam, a propofol infusion was started at a rate which varied between 0-300 mg/h (0-30 ml/h). The actual infusion rate was adjusted in order to maintain the optimum sedation level which had been achieved using midazolam. The quality of sedation was assessed using Ellis and Sedation scores.

RESULTS

Midazolam dosage varied between 5 and 14 mg. The initial propofol infusion rate was 200 mg/h (20 ml/h) for 21 of the 23 implant surgery treatments.

CONCLUSION

The sedation technique described takes advantage of the differing pharmacokinetic properties of midazolam and propofol. Initial sedation was achieved using midazolam, this was then maintained using a variable propofol infusion. The shorter distribution and elimination half-lifes of the latter drug made matching the level of sedation to the patient's needs easier and also provided good short-term recovery.

Tocolytic magnesium sulfate exposure and risk of cerebral palsy among children with birth weights less than 1,750 grams

The authors examined the relation between intrapartum magnesium sulfate exposure and risk of cerebral palsy in a case-control study of low birth weight children designed to control for confounding by the clinical indications for magnesium in pregnancy. Case children (n = 97) included all singleton children with cerebral palsy who were born in 1985-1989 in Atlanta, Georgia with a birth weight less than 1,750 g and whose mothers had not had a hypertension-related disease during pregnancy. Control children (n = 110) were randomly selected from the infant survivors using identical selection criteria. Data on magnesium sulfate exposure, labor and delivery, and infant characteristics were abstracted from hospital records. The authors found no association between exposure to magnesium sulfate and cerebral palsy risk (odds ratio = 0.9; 95% confidence interval: 0.3, 2.6) either in all children or in subgroups with varying likelihoods for exposure to magnesium. However, the association did vary by birth weight, with a protective effect being seen in children born weighing less than 1,500 g and an elevated risk in children with birth weights of 1,500 g or more; all confidence intervals included 1.0 except for the combined <1,500 g group. Several ongoing randomized clinical trials of magnesium and cerebral palsy may shed more definitive light on this relation.

Oral midazolam for adults with learning disabilities

This paper demonstrates how oral midazolam can be employed as an alternative method of behaviour management to general anaesthesia for the dental treatment of people with learning disabilities. A range of treatments, from scaling to root canal therapy, can be carried out successfully using the sedation technique outlined. The advantages of sedation include reduced morbidity and mortality. Treatment outcomes are also likely to be improved as root canal therapy and periodontal care can be carried out over a number of visits rather than a single treatment session under general anaesthesia. Oral sedation with midazolam should improve the scope of dental treatment available to patients with disabilities.

Management of menstrual migraine

Migraines may occur at any time during the menstrual cycle but are commonly associated with the menses. Migraine-specific medications, such as the triptans, may be effective for acute management of menstrual migraine. However, it is important to recognize the relationship between migraines and the menstrual cycle because these headaches may not respond to the usual antimigraine medications. In that case, management may involve perimenstrual migraine prophylaxis, with migraine-specific medications used in addition for severe breakthrough migraines. Prostaglandin inhibitors started just before the time of headache vulnerability may prevent menstrual migraine attacks or reduce the severity of the headaches. Estrogen withdrawal has been shown to precipitate migraine headaches, and a sustained elevated level of estrogen will postpone the migraine. Transdermal estrogen started just before menstruation can provide a sustained low level of estrogen, decreasing the degree of estrogen decline, and thus may prevent induction of migraines. Ergotamine tartrate is usually taken only for acute migraine, but may also be effective for prevention of menstrual migraine when used regularly once or twice per day during the time of risk. By understanding the underlying pathophysiology of the relationship between migraines and the menstrual cycle, the physician can successfully treat migraines associated with menses.

Treatment of malnutrition with 1.1% amino acid peritoneal dialysis solution: results of a multicenter outpatient study

A peritoneal dialysis (PD) solution containing 1.1% amino acids as the osmotic agent was evaluated in a 3-month randomized, prospective, open-label study in malnourished PD patients. Patients in the treatment group (DAA) received one or two exchanges daily with the amino acid solution, depending on tolerance, in place of glucose solutions. Controls (DD) received their usual therapy with glucose dialysate. Fifty-four DAA and 51 DD patients completed the study. In DAA, but not in DD patients, there was a significant increase at month 3 in serum insulin-like growth factor-1 (IGF-1) levels and significant decreases in serum potassium (all 3 months) and inorganic phosphorus levels (months 1 and 3), indicating a general anabolic response. Prealbumin and transferrin levels were significantly increased in DAA but not in DD patients at month 1, but the groups did not differ at months 2 and 3. In patients with baseline albumin levels less than 3.5 g/dL (bromcresol green [BCG] method), DAA patients showed increases in albumin, transferrin (months 1 and 2), and prealbumin levels (all 3 months) relative to baseline values, whereas these serum protein levels were unchanged in DD patients, although the changes from baseline did not differ between groups. In this subgroup, midarm muscle circumference (MAMC) did not change in DD or DAA patients. In patients with baseline albumin levels of 3.5 g/dL or greater, DD patients had decreases in albumin and total protein levels at all 3 months and in prealbumin levels at months 1 and 2, relative to baseline. In DAA patients, there were fewer changes in serum proteins. MAMC increased significantly from baseline in DAA but not in DD patients, although changes from baseline did not differ between DAA and DD groups. DAA patients showed no changes in peritoneal membrane transport characteristics. The results indicate that treatment with one or two exchanges daily of this amino acid-based PD solution is safe and provides nutritional benefit for malnourished PD patients.

Alcohol consumption by pregnant women in the United States during 1988-1995

OBJECTIVE

To examine trends in alcohol use among pregnant women in the United States and to characterize pregnant women who use alcohol, with an emphasis on frequent use (at least five drinks per occasion or at least seven drinks per week).

METHODS

We used the Behavioral Risk Factor Surveillance System data from 1988 through 1995 to obtain the percentage of pregnant women who used alcohol. We used multiple logistic models to identify subgroups of pregnant women who are at increased risk for alcohol use.

RESULTS

Overall, 14.6% (869 of 5983) of pregnant women consumed alcohol and 2.1% (133 of 5983) consumed alcohol frequently. Among pregnant women, alcohol use decreased from 22.5% (95% confidence interval [CI] 20.8, 23.9) in 1988 to 9.5% (95% CI 7.9, 11.8) in 1992 and then increased to 15.3% (95% CI 13.1, 17.2) by 1995. Among pregnant women, frequent alcohol use decreased from 3.9% (95% CI 2.4, 5.2) in 1988 to 0.9% (95% CI 0.4, 1.6) in 1991 and then increased to 3.5% (95% CI 2.0, 5.1) by 1995. Pregnant women who were at high risk for alcohol use were college educated, unmarried, employed, or students, had annual household incomes of more than $50,000, or were smokers. Pregnant women who were at high risk for frequent alcohol use were more likely to be unmarried, or smokers.

CONCLUSION

The increasing prevalence of alcohol use among pregnant women calls for increased ascertainment of alcohol use among preconceptional and pregnant women. Brief interventions by clinicians, increased referral to alcohol treatment programs, and increased use of contraception by women of reproductive age who are problem drinkers should be considered as means of preventing alcohol-exposed pregnancies.

Paternal dioxin, preterm birth, intrauterine growth retardation, and infant death

We studied paternal exposure to Agent Orange and its dioxin contaminant (2,3,7,8-tetrachlorodibenzo-p-dioxin) and preterm birth, intrauterine growth retardation, or infant death in veterans of Operation Ranch Hand, the unit responsible for spraying herbicides during the Vietnam war. A Comparison group of Air Force veterans who served in Southeast Asia during the same time period and who were not occupationally exposed to herbicides was included. We studied children conceived during or after the father's service in Southeast Asia and based exposure on paternal dioxin measured in 1987 or 1992 extrapolated to the time of conception of the child. We assigned each child to one of four exposure categories: Comparison and three Ranch Hand categories (Background, Low, High). Children in the High (relative risk = 1.3) and Background (relative risk = 1.4) categories were at increased risk of preterm birth. The risk of intrauterine growth retardation was not increased in any exposure category. The risk of infant death was increased in all Ranch Hand children, with the greatest increases in the High (relative risk = 4.5) and Background (relative risk = 3.2) categories. These patterns indicate that the increases in the relative risk of preterm birth and infant death may not be related to paternal dioxin level.

DNA immunization for influenza virus: studies using hemagglutinin- and nucleoprotein-expressing DNAs

DNA-based immunizations have been used to analyze the ability of DNA-expressed hemagglutinin (HA) and nucleoprotein (NP) to protect BALB/c mice against a homologous influenza virus, A/PR/8/34 (H1N1), challenge. The HA DNA, but not the NP DNA, protected mice against the lethal viral challenge. For the HA DNA, single gene gun inoculations of 0.04 microg and boosted inoculations of 0.004 microg of DNA raised complete protection. For the NP DNA, boosted gene gun immunizations of 0.4 microg of DNA and boosted intradermal or intramuscular injections of 50 microg of DNA failed to protect. The protection elicited by the HA DNA vaccine correlated with the titers of neutralizing antibody.

Carbon Pool Dynamics in the Lower Fraser Basin from 1827 to 1990

/ To understand the total impact of humans on the carbon cycle, themodeling and quantifying of the transfer of carbon from terrestrial pools tothe atmosphere is becoming more critical. Using previously published data,this research sought to assess the change in carbon pools caused by humans inthe Lower Fraser Basin (LFB) in British Columbia, Canada, since 1827 anddefine the long-term, regional contribution of carbon to the atmosphere. Theresults indicate that there has been a transfer of 270 Mt of carbon frombiomass pools in the LFB to other pools, primarily the atmosphere. The majorlosses of biomass carbon have been from logged forests (42%), wetlands(14%), and soils (43%). Approximately 48% of the forestbiomass, almost 20% of the carbon of the LFB, lies within old-growthforest, which covers only 19% of the study area. Landfills are nowbecoming a major sink of carbon, containing 5% of the biomass carbonin the LFB, while biomass carbon in buildings, urban vegetation, mammals, andagriculture is negligible. Approximately 26% of logged forest biomasswould still be in a terrestrial biomass pool, leaving 238 Mt of carbon thathas been released to the atmosphere. On an area basis, this is 29 times theaverage global emissions of carbon, providing an indication of the pastcontributions of developed countries such as Canada to global warming andpossible contributions from further clearing of rainforest in both tropicaland temperate regions.KEY WORDS: Carbon pools; Global warming; Carbon release to atmosphere;Greenhouse effect

Surveillance of developmental disabilities with an emphasis on special studies

The developing central nervous system seems to be particularly vulnerable to chemical insults. A model for developmental disabilities surveillance is presented that provides a reasonable framework for monitoring the prevalence of various developmental abnormalities in human populations. Effective monitoring will not only increase the likelihood of detecting the adverse effects of new physical or chemical agents in the environment but will provide a readily available case series for specially directed case-control studies. A specific example is provided of a large case-control study of cerebral palsy and intrapartum magnesium exposure among very low birth weight children, which is being conducted within the framework of a developmental disabilities surveillance program.

Prenatal magnesium sulfate exposure and the risk for cerebral palsy or mental retardation among very low-birth-weight children aged 3 to 5 years

OBJECTIVE

To examine the relationship between prenatal magnesium sulfate exposure and the risk for cerebral palsy (CP) or mental retardation (MR) among very low-birth-weight (VLBW; <1500 g) children. Secondarily, to investigate the effect of prenatal magnesium sulfate exposure on VLBW infant mortality.

DESIGN

Cohort study with follow-up to 1 year of age; a subset followed up to 3 to 5 years.

SETTING

Twenty-nine Georgia counties, including the 5-county Atlanta metropolitan area.

PARTICIPANTS

All VLBW births (N=1097) occurring during 2 years (1986-1988); all metropolitan Atlanta VLBW neonates who survived infancy (N=519).

MAIN OUTCOME MEASURES

Infant mortality as determined from vital statistics records. Development of CP or MR by 3 to 5 years of age among metropolitan Atlanta VLBW survivors as determined from the Metropolitan Atlanta Developmental Disabilities Surveillance Program.

RESULTS

For the entire cohort, there was no association between prenatal magnesium sulfate exposure and infant mortality (adjusted rate ratio, 1.02; 95% confidence interval [CI], 0.83-1.25). Among Atlanta-born survivors, those exposed to magnesium sulfate had a lower prevalence of CP or MR than those not exposed (CP: magnesium sulfate, 0.9%, no magnesium sulfate, 7.7%, crude odds ratio [OR], 0.11, 95% CI, 0.02-0.81; MR: magnesium sulfate, 1.8%, no magnesium sulfate, 5.8%, crude OR, 0.30, 95% CI, 0.07-1.29). Multivariable adjustment had no appreciable effect on the ORs for CP or MR, but the CIs included 1.0.

CONCLUSIONS

A reduced risk for CP, and possibly MR, among VLBW children is associated with prenatal magnesium sulfate exposure. The reduced risk for childhood CP or MR does not appear to be due to selective mortality of magnesium sulfate-exposed infants.

Auditing clinical teaching in oral surgery: the use of a student log book

Objective assessments of clinical teaching are difficult; in oral surgery students must acquire a wide range of clinical and operative skills before qualifying as independent dental practitioners. A student log book system was introduced in Manchester University to monitor student progress and assess the efficacy of clinical instruction in oral and maxillofacial surgery following the introduction of the new 5-year BDS curriculum. Initial appraisal of third- and fourth year students undertaking 10-week clinical attachments revealed generally high levels of attendance (greater than 80%), and reasonable clinical experience (over 80% of students acquiring regular experience of dentoalveolar surgery and extractions). However, individual variation in both attendance and achievement was wide, and a persistent 8% of students did not appear to gain any practical experience. Students achieving less than the average course performance marks were thus easily identified and measures initiated to identify and correct their difficulties. Log book assessment also facilitated effective audit of teaching staff, clinical sessions and overall course delivery. The use of student log books to record clinical performance is recommended as a versatile aid to clinical teaching practice.

Prevalence of selected developmental disabilities in children 3-10 years of age: the Metropolitan Atlanta Developmental Disabilities Surveillance Program, 1991

PROBLEM/CONDITION

Serious developmental disabilities affect approximately 2% of school-age children and are lifelong conditions that incur substantial financial and societal costs.

REPORTING PERIOD

January 1991-December 1991.

DESCRIPTION OF SYSTEM

The Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) monitors the prevalence of four serious developmental disabilities--mental retardation, cerebral palsy, vision impairment, and hearing impairment--among children 3-10 years of age in the five-county metropolitan-Atlanta area. Children who have at least one of the four developmental disabilities are ascertained through annual review of records at schools, hospitals, and other sources.

RESULTS AND INTERPRETATION

During 1991, rates for mental retardation varied by age, race, and sex; rates ranged from 5.2 per 1,000 children to 16.6 per 1,000 children. Regardless of the absolute rate of mental retardation in each of the age-, race-, and sex-specific categories, severe mental retardation (i.e., an intelligence quotient of <50) accounted for one third of all cases. The overall crude rate of cerebral palsy was 2.4 per 1,000 children; however, the rate was higher among black children (3.1 per 1,000 children) than among white children (2.0 per 1,000 children). The rate of moderate to severe hearing impairment was 1.1 per 1,000 children, and the rate of vision impairment was 0.8 per 1,000 children. Rates of hearing impairment were higher among black males than among children in the other race and sex groups, whereas rates for vision impairment varied only slightly between these groups. The rates of the developmental disabilities were not adjusted for possible confounding factors (e.g., maternal education, family income, and various medical conditions). Consequently, the variation in rates may reflect social or other characteristics unique to the study population.

ACTIONS TAKEN

MADDSP data will be used to direct early childhood intervention efforts to reduce the prevalence of these four developmental disabilities. MADDSP data also are being used to measure progress toward the year 2000 national objectives for the prevention of serious mental retardation.

Using a time-flow study to identify ambulatory surgical delays

Identification of surgical delays in an ambulatory care setting is essential for providing consumer-sensitive nursing care. One method of identifying and documenting surgical delays is described. This method, a time-flow study, allowed a freestanding ambulatory surgical center to identify problem areas within its scope of operations, and to provide a factual basis for implementing solutions as part of a continuous quality improvement and cost analysis program.

Dihydroergotamine and metoclopramide in the treatment of organic headache

Dihydroergotamine and metoclopramide have been used in the treatment of benign headache for many years. The presumed mechanism of action of dihydroergotamine and metoclopramide is related to these drugs' affinity for serotonergic receptors. We present three cases of the use of dihydroergotamine and metoclopramide in patients with organic headache (two patients with viral meningitis and one patient with meningeal carcinomatosis). All three patients had excellent symptomatic relief. Our results demonstrate that dihydroergotamine and metoclopramide can be effective in treating organic headache and, therefore, symptomatic relief can not be assumed to signify benign disease.

The relationship between maternal education and mental retardation in 10-year-old children

We conducted a case-control study of mental retardation (MR) in which case children (aged 10 years) were identified from existing records at multiple sources, primarily the public school systems. Control children were drawn from a roster of public school students not receiving special education services. We found that maternal educational level at the time of delivery was strongly and inversely related to a form of MR not accompanied by other serious neurologic conditions. For this isolated form of MR, maternal educational level was by far the most important predictor from among seven sociodemographic variables examined. There was a significant race-education interaction that indicated a steeper gradient in risk among white mothers than among black mothers. Relative to children of white mothers with 12 years of education, all children of black mothers, except those whose mothers had 16 or more years of education, were at increased risk. The results may be useful as a guide for selecting high-risk groups as candidates for early childhood intervention programs.

The accuracy of hospital records and death certificates for acute myocardial infarction

BACKGROUND

In Australia information on the incidence of acute myocardial infarction (AMI) is available from routinely collected morbidity and mortality data. Given that these data are used for monitoring AMI it is important to assess their quality.

AIMS

This paper examines the accuracy of the hospital records and death certificates.

METHODS

Morbidity and mortality data were compared with the Newcastle heart disease register which is part of the WHO MONICA Project for 1986-1991 and sensitivity and positive predictive values calculated.

RESULTS

For non-fatal AMI the hospital diagnostic coding had sensitivity of 78.9% (95% confidence interval [CI] 77.1%-80.7%), and positive predictive value of 65.6% (95% CI 63.7%-67.4%). Sensitivity was higher for men than for women and decreased with increasing age. Sensitivity was higher in those with no history of either AMI or other ischaemic heart disease (IHD), higher in current smokers than ex-smokers or never smokers, and lower in those with a self-reported history of high blood pressure. Sensitivity also varied among hospitals. Positive predictive value varied only with hospital. Both sensitivity and positive predictive value were high for death certificate data--89.9% (95% CI 88.4%-91.3%) and 96.0% (95% CI 95.1%-97.0%), respectively.

CONCLUSIONS

Although the mortality data appear to be quite accurate, the hospital data alone are not accurate enough to be used to estimate rates or trends of heart attacks. Additional data are required in order to determine numbers of non-fatal AMIs accurately.

Pneumonia with pleural effusion due to Legionella pneumophila serogroup Lansing 3

We describe a case of pneumonia with pleural effusion due to Legionella pneumophila serogroup Lansing 3 in a human immunodeficiency virus-infected person. The 55-year-old man had been treated with immunosuppressive agents for hypersensitivity pneumonitis.

Leisure-time physical activity and other health behaviours: are they related?

Data on the associations between leisure-time physical activity and other health behaviours are conflicting. The National Heart Foundation 1989 Risk Factor Prevalence Survey data were analysed to examine the associations between leisure-time physical activity and other life-style health behaviours in a national representative sample with adjustment for potential confounders. Multivariate stepwise logistic regression analysis using data from 9054 respondents aged 20 to 69 years showed that participation in leisure-time physical activity, even when it was not vigorous, was weakly associated with not smoking, following a special diet and moderate consumption of alcohol; it was inversely associated with obesity. These weak associations could influence health practices at a population level if, as has been hypothesised, the adoption of leisure activity promotes the adoption of other good health practices. Confirmation of earlier findings of cross-sectional associations between activity and other positive health practices justifies future prospective or experimental studies to determine the behavioural response to adoption of leisure-time physical activity.

A randomised controlled trial of a dietary advice program for relatives of heart attack victims

OBJECTIVE

To compare two interventions for reducing dietary fat intake in first degree relatives of recent heart attack victims.

DESIGN

A randomised controlled trial comparing a low cost mail-out advice program; referral to a general practitioner (GP); and no intervention (control group).

PARTICIPANTS

Adult children or siblings, aged less than 70 years, of survivors of definite or suspected heart attack who had been admitted to hospitals in the Lower Hunter Region of New South Wales.

MAIN OUTCOME MEASURES

Dietary fat intake (evaluated with a validated short questionnaire) and measurement of blood cholesterol levels at six months.

RESULTS

Of the 342 relatives who participated (36% of those invited), 109, 120 and 113, respectively, were randomly assigned to receive a mail-out intervention, advice from their GP or to be part of a control group. The six-month follow-up questionnaire was completed by only 59% of those in the mail-out intervention group compared with 71% of the GP group and 77% of the control group. Younger participants, cigarette smokers and children (compared with siblings) were less likely to return a follow-up questionnaire. The mail-out group showed a statistically significant 20% reduction in self-reported dietary fat intake, but this was not seen in either the GP group or the controls. The low response rate meant the study had insufficient power to detect hypothesised changes in blood cholesterol.

CONCLUSION

Because of the poor response rate and possible biases from a differential response to follow-up, we conclude that this low intensity intervention for relatives of people with recent heart attack produces only a modest improvement in reported dietary fat intake. Alternative strategies may be more effective in reducing the risk of heart disease.

Contribution of developmental disabilities to childhood mortality in the United States: a multiple-cause-of-death analysis

Although developmental disabilities are among the major chronic health problems affecting children in the United States, the contribution of developmental disabilities to childhood mortality is unknown. To investigate the magnitude of this contribution, multiple cause-of-death data were examined for US children, aged 1-19 years, for 1980 and 1983-1989. The following conditions were included as developmental disabilities: autism, attention deficit disorder, learning disorders, mental retardation, cerebral palsy, epilepsy, muscular dystrophy, blindness and deafness. Based on underlying cause only, it was found that developmental disabilities were the fifth leading cause of nontraumatic death for children between 1 and 14 years of age and the third leading cause of non-traumatic death for children between 15 and 19 years. When a multiple cause approach was used to define developmental disability-related deaths (i.e. when contributing as well as underlying cause was considered), the number of such deaths nearly doubled. On the basis of both underlying- and multiple-cause analyses, cerebral palsy was the developmental disability most frequently cited as a cause of death. Mental retardation ranked second according to the multiple-cause approach but only fourth according to the underlying-cause approach. The least frequent causes of death (autism, attention deficit disorder, learning disorders, blindness, and deafness) were the ones most likely to be coded as contributing rather than underlying causes. Developmental disability-related mortality rates were highest among children aged 1-4 and 15-19 years, highest among blacks and lowest among racial groups other than blacks and whites, and higher among males than females. Although results of multiple-cause-of-death analyses more accurately reflect the proportion of deaths related to developmental disabilities, even this approach may underestimate the degree to which mortality is associated with a developmental disability.

Prevalence and health impact of developmental disabilities in US children

OBJECTIVE

Data from the 1988 National Health Interview Survey--Child Health Supplement were used to examine the prevalence of selected developmental disabilities and their impact among children ages 0 through 17 years.

DESIGN

The following conditions, identified through a structured in-person interview with a parent or other adult household member, were examined: deafness or trouble hearing, blindness, epilepsy or seizures, stammering and stuttering, other speech defects, cerebral palsy, delay in growth or development, learning disabilities, and emotional or behavioral problems. The impact was defined by measures of perceived health status, school performance and attendance, and health care utilization.

RESULTS

Seventeen percent of children in the United States were reported to have ever had a developmental disability. The prevalence of the individual disabilities ranged from 0.2% for cerebral palsy to 6.5% for learning disabilities. These conditions taken together had a substantial impact on the health and educational functioning of affected children: 1.5 times more doctor visits, 3.5 times more hospital-days, twice the number of school-days lost, and a 2.5-fold increase in the likelihood of repeating a grade in school compared with children without these conditions. The extent of this impact was much greater among children with multiple disabilities or with either cerebral palsy, epilepsy or seizures, delays in growth and development, or emotional or behavioral problems. The impact on school performance was most pronounced for children reported to have learning disabilities.

CONCLUSIONS

Future research efforts should be focused on ways to reduce the impact of these developmental disabilities on quality of life.

Prevalence of depression among electrical workers

To address the possible association between electric and magnetic field exposure and depression, we analyzed data from the Vietnam Experience Study. In order to compare the risk of diagnosed depression, depressive symptoms, and elevations in personality scales indicative of depression, we classified employed participants as electrical workers (N = 183) and nonelectrical workers (N = 3,861) and compared their scores on the Diagnostic Interview Survey (DIS) and the Minnesota Multiphasic Personality Inventory (MMPI). Electrical workers in the aggregate showed little evidence of increased risk, with the possible exception of an increase in elevated MMPI depression scores among short-term workers. Data on electricians yielded indications of increased risk for several markers of depression. Despite the limited number of electrical workers, uncertainty regarding exposure, and our inability to address other workplace exposures, these results suggest that electrical workers in general are not at increased risk for depression. However, our results encourage further evaluation of depression among electricians.

Can the increasing weight of Australians be explained by the decreasing prevalence of cigarette smoking?

In Australia there has been a recent increase in the body mass index (BMI) of the population and a decrease in smoking prevalence. Data from the three risk factor prevalence surveys conducted by the National Heart Foundation of Australia in 1980, 1983 and 1989 were analysed to determine if the increase in BMI could be explained by the decrease in smoking. For men in all age groups and for women aged 50 years or over, there were parallel increases in mean BMI for current smokers, ex-smokers and never smokers. For women under 50 years, the pattern of increasing BMI over time was less clear. Mean BMI increased over time within each five-year age group and in age 'cohorts' and the pattern was independent of smoking status. For men and for both groups of women there were similar changes in mean BMI over time for most categories of employment status, education and physical activity. Thus the increase in body weight cannot be explained by the decrease in smoking rate, or by the other factors investigated in this paper.

Solar protection behaviours: a study of beachgoers

This study explored the prevalence and predictors of solar protection behaviour in a community sample of beachgoers. A total of 670 participants was randomly selected from six beaches in the Newcastle district. The solar protection behaviour of each participant was assessed by direct observation and interview. A subsample was also asked to complete a written questionnaire to assess attitudes to solar protection use, knowledge of skin cancer and awareness of recommended solar protection behaviours. Forty-five per cent of the beachgoers in this sample were using a high level of solar protection, and a substantial proportion (16 per cent) of the sample was not using any kind of solar protection. Sunscreen with SPF 15+ was applied to at least one body region by 69 per cent of the sample, 17 per cent of the sample were wearing a recommended hat, 15.1 per cent were using shade, and 3.4 per cent were wearing a recommended style of shirt at the time of observation. Chi-square analyses of the data for under-15-year-olds indicated that a significantly greater proportion of 0- to 9-year-olds were well protected compared to 11- to 14-year-olds, but there was no difference in use of protection by boys and girls under 15 years of age. Stepwise regression analysis of the adult sample (15 years and over) showed that the predictors of overall level of solar protection were marital status and frequency of skin self-examination in the past 12 months. The practical implications of these findings for future community-based skin cancer prevention programs are discussed.

Smoking control in restaurants: the effectiveness of self-regulation in Australia

OBJECTIVES

The provision of smoke-free areas in restaurants has been a controversial issue; the restaurant industry largely opts for a self-regulation approach. This study aimed to examine the effectiveness of self-regulation as a strategy in meeting the industry's and customers' perceived needs.

METHODS

Restaurateur and customer perspectives on the provision of smoke-free areas in restaurants were examined by survey among 365 restaurateurs and 1327 customers in New South Wales, Australia.

RESULTS

Less than 2% of restaurants were totally smoke-free; 22% provided some smoke-free areas. Customers were much more likely than owners to think that smoke-free areas should be provided. Owners appeared to be unaware of customers' views about smoke-free areas in restaurants.

CONCLUSIONS

Little evidence was found to support the effectiveness of the self-regulation policy adopted by the restaurant industry. Characteristics of restaurants and owners associated with the provision of smoke-free areas are presented and implications of the findings are discussed.