A longitudinal comparison of emotional, behavioral and attention problems in autistic and typically developing children

BACKGROUND

Mental health problems are elevated in autistic individuals but there is limited evidence on the developmental course of problems across childhood. We compare the level and growth of anxious-depressed, behavioral and attention problems in an autistic and typically developing (TD) cohort.

METHODS

Latent growth curve models were applied to repeated parent-report Child Behavior Checklist data from age 2-10 years in an inception cohort of autistic children (Pathways, N = 397; 84% boys) and a general population TD cohort (Wirral Child Health and Development Study; WCHADS; N = 884, 49% boys). Percentile plots were generated to quantify the differences between autistic and TD children.

RESULTS

Autistic children showed elevated levels of mental health problems, but this was substantially reduced by accounting for IQ and sex differences between the autistic and TD samples. There was small differences in growth patterns; anxious-depressed problems were particularly elevated at preschool and attention problems at late childhood. Higher family income predicted lower base-level on all three dimensions, but steeper increase of anxious-depressed problems. Higher IQ predicted lower level of attention problems and faster decline over childhood. Female sex predicted higher level of anxious-depressed and faster decline in behavioral problems. Social-affect autism symptom severity predicted elevated level of attention problems. Autistic girls' problems were particularly elevated relative to their same-sex non-autistic peers.

CONCLUSIONS

Autistic children, and especially girls, show elevated mental health problems compared to TD children and there are some differences in predictors. Assessment of mental health should be integrated into clinical practice for autistic children.

A multi-organ, lung-derived inflammatory response following in vitro airway exposure to cigarette smoke and next-generation nicotine delivery products

Despite increasing use of in vitro models that closely resemble in vivo human biology, their application in understanding downstream effects of airway toxicity, such as inflammation, are at an early stage. In this study, we used various assays to examine the inflammatory response induced in MucilAir™ tissues and A549 cells exposed to three products known to induce toxicity. Reduced barrier integrity was observed in tissues following exposure to each product, with reduced viability and increased cytotoxicity also shown. Similar changes in viability were also observed in A549 cells. Furthermore, whole cigarette smoke (CS) induced downstream phenotypic THP-1 changes and endothelial cell adhesion, an early marker of atherosclerosis. In contrast, exposure to next-generation delivery product (NGP) aerosol did not induce this response. Cytokine, histological and RNA analysis highlighted increased biomarkers linked to inflammatory pathways and immune cell differentiation following exposure to whole cigarette smoke, including GM-CSF, IL-1β, cleaved caspase-3 and cytochrome P450 enzymes. As a result of similar observations in human airway inflammation, we propose that our exposure platform could act as a representative model for studying such events in vitro. Furthermore, this model could be used to test the inflammatory or anti-inflammatory impact posed by inhaled compounds delivered to the lung.

Recent advancements and application of in vitro models for predicting inhalation toxicity in humans

Animals have been indispensable in testing chemicals that can pose a risk to human health, including those delivered by inhalation. In recent years, the combination of societal debate on the use of animals in research and testing, the drive to continually enhance testing methodologies, and technology advancements have prompted a range of initiatives to develop non-animal alternative approaches for toxicity testing. In this review, we discuss emerging in vitro techniques being developed for the testing of inhaled compounds. Advanced tissue models that are able to recreate the human response to toxic exposures alongside examples of their ability to complement in vivo techniques are described. Furthermore, technology being developed that can provide multi-organ toxicity assessments are discussed.

Non-verbal IQ and change in restricted and repetitive behavior throughout childhood in autism: a longitudinal study using the Autism Diagnostic Interview-Revised

BACKGROUND

Restricted and repetitive behavior (RRB) is one of the characteristic features of Autism Spectrum Disorder. This domain of symptoms includes a broad range of behaviors. There is a need to study each behavior individually to better understand the role of each in the development of autistic children. Moreover, there are currently no longitudinal studies investigating change in these behaviors over development.

METHODS

The goal of the present study was to explore the association between age and non-verbal IQ (NVIQ) on 15 RRB symptoms included in the Autism Diagnostic Interview-Revised (ADI-R) over time. A total of 205 children with ASD were assessed using the ADI-R at time of diagnosis, at age 6 years, and at age 11 years, and with the Wechsler Intelligence Scales for Children-Fourth Edition (WISC-IV) at age 8 years.

RESULTS

The proportion of children showing each RRB tended to diminish with increasing age, except for sensitivity to noise and circumscribed interests, where the proportion increased over time. Although there was no significant main effect of NVIQ, there was a significant interaction between age and NVIQ. This was mainly driven by Difficulties with change in routine, for which higher NVIQ was associated with the behavior remaining relatively stable with age, while lower NVIQ was associated with the behavior becoming more prevalent with age.

LIMITATIONS

The study focused on the presence/absence of each RRB but did not account for potential changes in frequency or severity of the behaviors over development. Furthermore, some limitations are inherent to the measures used. The ADI-R relies on parent report and hence has some level of subjectivity, while the Wechsler intelligence scales can underestimate the intellectual abilities of some autistic children.

CONCLUSIONS

These results confirm that specific RRB are differentially linked to age and NVIQ. Studying RRB individually is a promising approach to better understanding how RRB change over the development of autistic children and are linked to other developmental domains.

Cortical responses before 6 months of life associate with later autism

Autism spectrum disorder (ASD) is a common, highly heritable, developmental disorder and later-born siblings of diagnosed children are at higher risk of developing ASD than the general population. Although the emergence of behavioural symptoms of ASD in toddlerhood is well characterized, far less is known about development during the first months of life of infants at familial risk. In a prospective longitudinal study of infants at familial risk followed to 36 months, we measured functional near-infrared spectroscopy (fNIRS) brain responses to social videos of people (i.e. peek-a-boo) compared to non-social images (vehicles) and human vocalizations compared to non-vocal sounds. At 4-6 months, infants who went on to develop ASD at 3 years (N = 5) evidenced-reduced activation to visual social stimuli relative to low-risk infants (N = 16) across inferior frontal (IFG) and posterior temporal (pSTS-TPJ) regions of the cortex. Furthermore, these infants also showed reduced activation to vocal sounds and enhanced activation to non-vocal sounds within left lateralized temporal (aMTG-STG/pSTS-TPJ) regions compared with low-risk infants and high-risk infants who did not develop ASD (N = 15). The degree of activation to both the visual and auditory stimuli correlated with parent-reported ASD symptomology in toddlerhood. These preliminary findings are consistent with later atypical social brain responses seen in children and adults with ASD, and highlight the need for further work interrogating atypical processing in early infancy and how it may relate to later social interaction and communication difficulties characteristic of ASD.

The role of infants' mother-directed gaze, maternal sensitivity, and emotion recognition in childhood callous unemotional behaviours

While some children with callous unemotional (CU) behaviours show difficulty recognizing emotional expressions, the underlying developmental pathways are not well understood. Reduced infant attention to the caregiver's face and a lack of sensitive parenting have previously been associated with emerging CU features. The current study examined whether facial emotion recognition mediates the association between infants' mother-directed gaze, maternal sensitivity, and later CU behaviours. Participants were 206 full-term infants and their families from a prospective longitudinal study, the Durham Child Health and Development Study (DCHDS). Measures of infants' mother-directed gaze, and maternal sensitivity were collected at 6 months, facial emotion recognition performance at 6 years, and CU behaviours at 7 years. A path analysis showed a significant effect of emotion recognition predicting CU behaviours (β = -0.275, S.E. = 0.084, p = 0.001). While the main effects of infants' mother-directed gaze and maternal sensitivity were not significant, their interaction significantly predicted CU behaviours (β = 0.194, S.E. = 0.081, p = 0.016) with region of significance analysis showing a significant negative relationship between infant gaze and later CU behaviours only for those with low maternal sensitivity. There were no indirect effects of infants' mother-directed gaze, maternal sensitivity or the mother-directed gaze by maternal sensitivity interaction via emotion recognition. Emotion recognition appears to act as an independent predictor of CU behaviours, rather than mediating the relationship between infants' mother-directed gaze and maternal sensitivity with later CU behaviours. This supports the idea of multiple risk factors for CU behaviours.

Alternative reagents to antibodies in imaging applications

Antibodies have been indispensable tools in molecular biology, biochemistry and medical research. However, a number of issues surrounding validation, specificity and batch variation of commercially available antibodies have prompted research groups to develop novel non-antibody binding reagents. The ability to select highly specific monoclonal non-antibody binding proteins without the need for animals, the ease of production and the ability to site-directly label has enabled a wide variety of applications to be tested, including imaging. In this review, we discuss the success of a number of non-antibody reagents in imaging applications, including the recently reported Affimer.

Callous-unemotional traits moderate executive function in children with ASD and ADHD: A pilot event-related potential study

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Children with ASD and ADHD show varied and heterogeneous executive function (EF) profiles.

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Typical or enhanced EF has been demonstrated in individuals with callous-unemotional (CU) traits.

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We investigated the effect of CU traits on event-related potential (ERP) responses during a cued continuous performance test (CPT-OX) in children with ASD, ADHD and co-occurring ASD + ADHD.

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Children with ASD and high CU traits showed better conflict monitoring compared to children with ASD and low CU traits.

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Increased CU traits may be associated with cognitive strengths in children with ASD.

Attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD) are associated with varied executive function (EF) difficulties. Callous-unemotional (CU) traits, a proposed antecedent of adult psychopathy, are often associated with intact or enhanced EF. Here we test whether CU traits may therefore modulate EF in ASD and ADHD, in which EF is typically impaired. We collected CU traits and measured event-related potentials (ERPs) that index EF during a cued-continuous performance test (CPT-OX) in boys with ASD, ADHD, comorbid ASD + ADHD and typical controls. We examined attentional orienting at cues (Cue-P3), inhibitory processing at non-targets (NoGo-P3) and conflict monitoring between target and non-target trials (Go-N2 vs. NoGo-N2). In children with ASD, higher CU traits were associated with an enhanced increase in N2 amplitude in NoGo trials compared to Go trials, which suggests relatively superior conflict monitoring and a potential cognitive strength associated with CU traits. The results emphasise the importance of considering the effects of co-occurring traits in the assessment of heterogeneity of EF profiles in neurodevelopmental disorders.

Visual search performance in infants associates with later ASD diagnosis

An enhanced ability to detect visual targets amongst distractors, known as visual search (VS), has often been documented in Autism Spectrum Disorders (ASD). Yet, it is unclear when this behaviour emerges in development and if it is specific to ASD. We followed up infants at high and low familial risk for ASD to investigate how early VS abilities links to later ASD diagnosis, the potential underlying mechanisms of this association and the specificity of superior VS to ASD. Clinical diagnosis of ASD as well as dimensional measures of ASD, attention-deficit/hyperactivity disorder (ADHD) and anxiety symptoms were ascertained at 3 years. At 9 and 15 months, but not at age 2 years, high-risk children who later met clinical criteria for ASD (HR-ASD) had better VS performance than those without later diagnosis and low-risk controls. Although HR-ASD children were also more attentive to the task at 9 months, this did not explain search performance. Superior VS specifically predicted 3 year-old ASD but not ADHD or anxiety symptoms. Our results demonstrate that atypical perception and core ASD symptoms of social interaction and communication are closely and selectively associated during early development, and suggest causal links between perceptual and social features of ASD.

From early markers to neuro-developmental mechanisms of autism

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Studies of infants at-risk could reveal the developmental origin of autism.

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Behavioral and brain markers differentiate infants that develop autism symptoms from controls, during the first year of life.

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Little evidence for decreased social orienting or social motivation.

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Some evidence for multiple developmental pathways to autism.

A fast growing field, the study of infants at risk because of having an older sibling with autism (i.e. infant sibs) aims to identify the earliest signs of this disorder, which would allow for earlier diagnosis and intervention. More importantly, we argue, these studies offer the opportunity to validate existing neuro-developmental models of autism against experimental evidence. Although autism is mainly seen as a disorder of social interaction and communication, emerging early markers do not exclusively reflect impairments of the “social brain”. Evidence for atypical development of sensory and attentional systems highlight the need to move away from localized deficits to models suggesting brain-wide involvement in autism pathology. We discuss the implications infant sibs findings have for future work into the biology of autism and the development of interventions.

Failure to learn from feedback underlies word learning difficulties in toddlers at risk for autism

Children's assignment of novel words to nameless objects, over objects whose names they know (mutual exclusivity; ME) has been described as a driving force for vocabulary acquisition. Despite their ability to use ME to fast-map words (Preissler & Carey, 2005), children with autism show impaired language acquisition. We aimed to address this puzzle by building on studies showing that correct referent selection using ME does not lead to word learning unless ostensive feedback is provided on the child's object choice (Horst & Samuelson, 2008). We found that although toddlers aged 2;0 at risk for autism can use ME to choose the correct referent of a word, they do not benefit from feedback for long-term retention of the word-object mapping. Further, their difficulty using feedback is associated with their smaller receptive vocabularies. We propose that difficulties learning from social feedback, not lexical principles, limits vocabulary building during development in children at risk for autism.

Report on the joint IBEPAG/ICCBBA survey on import/export and blood component labelling

A survey of blood centre organizations was carried out to establish the degree of progress towards the implementation of global standards for coding and labelling blood components. The survey was performed through questionnaires completed by blood organizations. Of nearly 32 million blood donations collected annually by the participants, 43% are identified with ISBT 128 donation numbers and 36% are fully compliant with the ISBT 128 Standard. Planned implementations indicate that 85% of donations will be identified by ISBT 128 donation numbers by 2011.

Preliminary evaluation of the prototype stereoscopic endoscope: precise three-dimensional measurement system

A prototype stereoscopic endoscope (incorporating two charged-coupled devices), developed for the accurate three-dimensional measurement of gastrointestinal tract lesions, was initially evaluated with two-dimensional target grids and in vitro measurement of 15 objects of known size (marbles, cubes, and rectangular prisms) placed in a plastic model of the sigmoid colon. Images of the objects were captured and stored in a computer. Stereoscopic measurements were compared with results from the standard (open biopsy forceps) method by a blinded endoscopist. The volume measured with the stereoscope did not differ significantly from the true volume, whereas the volume obtained with the open biopsy forceps method differed significantly from the actual volume, consistently underestimating the actual size. The aberration ratios (percentage deviation between the measured and true volume, expressed as mean +/- SD) obtained with the stereoscopic endoscope were superior (9.2% +/- 9.5%) to those obtained with the open biopsy forceps method (-34.0% +/- 26.8%). These preliminary in vitro results with the stereoscope show considerable promise for the simple and precise three-dimensional measurement of gastrointestinal lesions and warrant human clinical trials.

Endoscopic ultrasound does not accurately assess pathologic stage of esophageal cancer after neoadjuvant chemoradiotherapy

The accuracy of endoscopic ultrasound (EUS) for initial staging of esophageal cancer is widely accepted. There is, however, considerable variability in the reported accuracy of EUS for restaging of esophageal neoplasms after neoadjuvant therapy. From June 1995 through December 1999, we prospectively studied a series of 26 patients who underwent neoadjuvant treatment for esophageal cancer and were subsequently restaged by EUS before resection. Twenty-four patients had adenocarcinoma (92%), and two patients had squamous cell carcinoma (8%). EUS correctly predicted tumor stage in seven of 26 patients for an overall accuracy of 27 per cent. EUS overestimated the depth of tumor penetration in 18 patients (69%) and underestimated depth of penetration in one patient (4%). Lymph nodes were correctly staged in 15 of 26 patients for an overall accuracy of 58 per cent. Levels of sensitivity for detecting N0 and N1 disease were 44 per cent and 80 per cent respectively. Patients with a complete pathologic response were staged as T4N1 (one patient), T3N1 (three patients), T3N0 (one patient), and T2N1 (two patients). EUS cannot distinguish tumor involvement of the esophageal wall and lymph nodes from the postinflammatory changes that characterize effective neoadjuvant treatment. EUS is of limited utility in guiding clinical decision making after neoadjuvant therapy.

Endoscopic retrograde cholangiopancreatography under general anesthesia: indications and results

BACKGROUND

Conscious sedation is usually used during endoscopic retrograde cholangiopancreatography (ERCP). Little is known about the indications and outcomes for ERCP in patients who cannot undergo conscious sedation and therefore require general anesthesia. We retrospectively evaluated the indications and outcome for patients undergoing ERCP who required general anesthesia at four teaching hospitals over a 2-year period.

METHODS

Of 1200 ERCPs performed over a 2-year period, 65 patients required general anesthesia. Retrospective chart analysis was undertaken to determine indications and outcomes of ERCP performed under general anesthesia. Eleven patients underwent sphincter of Oddi manometry.

RESULTS

The major indication for general anesthesia was substance abuse. Therapeutic intervention was successful in 45 of 48 patients; 6 of the 63 patients had complications, all mild and not related to the anesthesia. Sphincter of Oddi manometry was normal in 7 patients; 4 patients had elevated basal pressures.

CONCLUSIONS

ERCP under general anesthesia may be considered when conscious sedation fails to achieve a satisfactory level of sedation for a successful and safe ERCP. Procedure-related complication rates appear to be comparable if not lower with general anesthesia.

International migration, 1995: some reflections on an exceptional year

"This paper examines the 1995 international migration statistics in the context of New Zealand's immigration policy, and with reference to the impact of migration on population change in 1995. Particular attention is focused on trying to unravel and interpret the statistics relating to net migration. Considerable confusion has arisen in the public debate about immigration because of uniformed and, at times, quite misleading use of information supplied by Statistics New Zealand and the Department of Labour.... This is a reprinted version of an article originally published in the New Zealand Journal of Geography in April 1996. The article has been reprinted because a number of tables in the earlier version were incorrectly reproduced. Any inconvenience caused by this problem is regretted."

A retreat: the benefits to nurse education

The informality of an educational retreat can break down traditional barriers to learning and self-knowledge. A retreat can encourage autonomy, teamwork and reflection

Collagenous colitis. A treatable disease with an elusive diagnosis

Collagenous colitis is associated with normal endoscopy examination and peculiar histopathological changes. The natural history and optimal treatment are not well defined. Our objectives were to analyze the symptomatology of collagenous colitis, determine the natural history, and response to treatment. All patients with collagenous colitis from 1978 to 1992 were studied. Demographic data, symptomatology, associated conditions, colonoscopic findings, and pathology specimens were reviewed. Clinical improvement was classified as none, partial, or complete. Nineteen patients were identified, mainly white females over age 50. Mean follow-up was 22.6 months. Symptom duration was 37 months (range 4 months to 15 years). Symptoms were intermittent diarrhea (19), with a predominant nocturnal component (13); abdominal pain (15); and mild weight loss and incontinence (8). Colonoscopy was normal in 12 patients. Segmental mucosal edema and loss of vasculature pattern were present in seven. Antiperistaltic agents were used in 17 patients with no improvement (15), partial resolution (1), and complete resolution (1). Eight nonresponders received sulfasalazine. Responses were none (6) or complete (2). Ten patients received steroids (10-20 mg/day). One failed to respond. Nine initially responded completely but two relapsed. Seven patients who did not respond to any type of treatment improved eventually, two partially and five completely. These patients were younger (54.3 vs 68.3 years, P = 0.04) and symptom duration was shorter (25.4 vs 44.5 months, P = 0.38) than the rest of the patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Isoflurane and nitrous oxide: comparative impact on cerebrospinal fluid pressure in patients with brain tumors

The relative effects on cerebrospinal fluid pressure (CSFP) of equipotent concentrations of isoflurane and N2O were compared in 20 patients with brain tumors who had lumbar subarachnoid catheters in place. Patients were randomly assigned to receive one of two anesthetic sequences: group 1, 0.7% end-tidal isoflurane in O2, which was changed to 70% N2O in O2; or group 2, 70% N2O in O2, which was changed to 0.7% end-tidal isoflurane in O2. End-tidal PCO2 and percent end-tidal N2O and isoflurane were monitored by mass spectrometry from just before changing anesthetics (time = 0 min) until the end of a 20-min observation period (time = 20 min). Ventilation was held constant at PaCO2 = 36 +/- 1 mm Hg (mean +/- SE). The patients in group 1 sustained an increase in CSFP that reached a maximum of 33% above the value at 0 min, despite a 3-mm Hg decrease in PaCO2 (P < 0.05). By contrast, CSFP remained unchanged in group 2. Although the absolute increase in CSFP after replacement of isoflurane/O2 by N2O/O2 anesthesia was relatively small (9 +/- 1 to 12 +/- 2 mm Hg; P < 0.05), the absence of a similar effect in patients where N2O was replaced by isoflurane suggests that replacement of isoflurane by an equipotent concentration of N2O is more likely to lead to an increase in CSFP in patients with altered intracranial dynamics than is replacement of N2O by isoflurane.

Health care professionals' knowledge about AIDS, prejudice and attitudes towards AIDS

In this study the authors examined knowledge of and attitudes to AIDS in a group of health care pofessionals. The results indicated high levels of knowledge about the disease. These results are regarded as positive findings, since their AIDS awareness showed the subjects were well informed and had formulated this knowledge from a relatively objective rather than judgemental/moralistic point of view. Three categories of attitudes were studied, that is, attitudes towards AIDS per se, attitudes towards homosexuality, and attitudes towards the sexuality of blacks. Attitudes towards AIDS per se varied considerably despite the relatively high levels of knowledge about the disease. Attitudes towards homosexuality had a substantial negative relationship with attitudes towards AIDS, a finding common to other studies. Attitudes towards AIDS were also related to attitudes towards the sexuality of blacks. It is concluded that attitudes towards AIDS in the group studied were substantially determined by historically grounded attitudes concerning the sexuality of marginalized groups. The implications of these findings as an additional component in combatting AIDS are discussed.

Tension pneumocephalus: treatment with controlled decompression via a closed water-seal drainage system. Case report

The successful treatment of a patient with tension pneumocephalus by controlled decompression via external drainage is described. The advantage of the technique includes the immediate release of high pressure and the capability of maintaining constant low pressure to enable and facilitate sealing of dural tears. The method has been used in three other patients, leading to resolution of the tension pneumocephalus without recurrence or other complications.

Cerebrospinal fluid pressure in patients with brain tumors: impact of fentanyl versus alfentanil during nitrous oxide-oxygen anesthesia

The effects on the cerebrospinal fluid pressure (CSFP) of alfentanil and fentanyl were compared during nitrous oxide-oxygen (N2O-O2) anesthesia in 24 patients who had brain tumors. Monitored variables included CSFP (lumbar subarachnoid catheter), heart rate from electrocardiographic lead II, mean radial arterial blood pressure, and arterial blood gas tensions. General anesthesia was induced with thiopental, 5 mg/kg IV in divided doses, and maintained with 70% N2O in O2; ventilation was held constant (PaCO2 = 37.4 +/- 1.6 mm Hg [mean +/- SEM]). After baseline data were recorded, 16 subjects were randomly assigned to receive either 5 micrograms/kg fentanyl as an intravenous bolus or 50 micrograms/kg alfentanil as an intravenous bolus, followed by an infusion of alfentanil at 1 micrograms.kg-1.min-1. Monitored variables were continuously recorded for 15 min after opioid injection. A third group of 8 patients was studied subsequently; they received only N2O-O2 during a 15-min observation period and served as controls. Blood pressure was held constant with an intravenous infusion of 0.1% phenylephrine, as needed; noxious stimulation was carefully avoided. Cerebrospinal fluid pressure remained unchanged both in patients who received N2O-O2 alone and in those who received fentanyl-N2O-O2. By contrast, those who received alfentanil-N2O-O2 had a gradual increase in CSFP, reaching 30% above baseline values after 10 min and stabilizing thereafter. Although the absolute increase in CSFP during normocarbic alfentanil-N2O anesthesia was relatively small (9.5 +/- 1.3 mm Hg to 13.0 +/- 1.3 mm Hg [mean +/- SE], P less than 0.05), the absence of a similar effect after fentanyl administration suggests that precautionary measures such as hyperventilation are advisable if alfentanil is used for potentiating normocarbic N2O-O2 anesthesia in neurosurgical patients with intracranial mass lesions.

Cerebrovasculr Response to CO2 in Edematous Brain During Either Fentanyl or Isoflurane Anesthesia

Cerebral blood flow response to changes in PaCO2 was studied in the edematous cerebral cortex of 19 patients with malignant supratentorial tumors using laser Doppler flowmetry technology. General anesthesia for craniotomy was induced with thiopental, 3-5 mg/kg i.v., and N2O, 60% in O2. In random sequence, 8 patients were assigned to receive fentanyl, 6 +/- 1.6 (SEM). mug/kg i.v.; the other 11 received isoflurane, 0.56% end-tidal + 0.07 (SEM). After a craniotomy bone flap was turned and the dura was opened, laser flowmetry probes were placed over surgically undisturbed cortex that was known to be edematous from preoperative CT and MRI scans. Flow index measurements were first made at hypocarbia (PaCO2 = 24.2 +/- 0.9 and 21.5 +/- 2.1 mm Hg for the fentanyl and isoflurane groups, respectively). Minute ventilation was then decreased and cortical flow index was remeasured with PaCO2 = 34.2 +/- 0.6 and 33.0 +/- 0.8 mm Hg for the fentanyl and isoflurane groups, respectively. Hypocarbia during fentanyl-supplemented N2O-O2 anesthesia resulted in a cortical flow index that was 70 +/- 8% of the flow index at near normocarbia (p <0.05). During isoflurane N2O-O2 anesthesia, however, there was a wide variety of responses to hypocarbia, including three patients whose flow indices increased markedly. The mean flow index during hypocarbia was significantly (p <0.05) lower during fentanyl-N2O anesthesia than it was during isoflurane-N2O anesthesia. There was no predictable relationship between the type of brain tumor and the CBF response to hypocapnia during isoflurane-N2O anesthesia. It is concluded that, in edematous brain, cerebral cortical blood flow response to hypocarbia is more likely to be preserved during fentanyl-supplemented N2O-O2 anesthesia than it is during isoflurane-supplemented N2O-O2 anesthesia. In neuropathologic states where hyperventilation is thought to be necessary to reduce cerebral blood flow and decrease brain bulk, isoflurane may be less satisfactory than fentanyl as a supplement to N2O-O2 anesthesia.

Esmolol for potentiation of nitroprusside-induced hypotension: impact on the cardiovascular, adrenergic, and renin-angiotensin systems in man

Esmolol infusion at rates of 200, 300, and 400 micrograms.kg-1.min-1 was used to potentiate hypotension (mean arterial pressure = 60 mm Hg) induced with sodium nitroprusside (SNP) in 10 male patients undergoing radical cancer surgery during nitrous oxide-oxygen and fentanyl anesthesia. Heart rate (HR), blood pressure (radial arterial catheter), and plasma levels of renin activity (PRA), norepinephrine (N), epinephrine (E), and dopamine (D) were measured: 1) while patients were awake; 2) after induction of anesthesia (nitrous oxide, 60% in oxygen, fentanyl = 5 micrograms/kg followed by an infusion at 10 micrograms.kg-1.hr-1); 3) after surgery had begun; 4) after 20 minutes of SNP-induced hypotension; 5) after 20 minutes of esmolol at each of the above infusion rates; and 6) after the completion of surgery. Compared to awake values, SNP-induced hypotension (mean infusion rate = 3.1 micrograms.kg-1.min-1 +/- 0.6 SE) during surgery resulted in significant (P less than 0.05) increases in heart rate, PRA, N, and D. Infusion of esmolol resulted in significant (P less than 0.05) dose-dependent reductions in SNP requirement to maintain MAP = 60 mm Hg. At 200 micrograms.kg-1.min-1, SNP requirement was 2.1 micrograms.kg-1.min-1 +/- 0.4, at 300 micrograms.kg-1.min-1, it was 1.0 micrograms.kg-1.min-1 +/- 0.2, and at 400 micrograms.kg-1.min-1, was 0.5 micrograms.kg-1.min-1 +/- 0.3. Concomitant with the decrease in SNP requirement, there were significant reductions in HR and PRA at all infusion rates of esmolol.(ABSTRACT TRUNCATED AT 250 WORDS)

Sufentanil, alfentanil, and fentanyl: impact on cerebrospinal fluid pressure in patients with brain tumors

In order to evaluate the safety of the new synthetic opioids, alfentanil and sufentanil, in neurosurgical patients, we administered sufentanil 1 microg/kg i.v., alfentanil 50 microg/kg i.v. followed by an infusion of 1 microg/kg/min, or fentanyl 5 microg/kg i.v. to 30 patients with supratentorial tumors anesthetized with nitrous oxide (N2O), 60% in O2. Lumbar cerebrospinal fluid pressure (CSFP) and mean arterial pressure (MAP) responses were recorded for 10 min thereafter, while ventilation was held constant [mean PaCO2 = 36.1 +/- 1.0 mm Hg (SEM)]. There was no change in CSFP after fentanyl. In contrast, both sufentanil and alfentanil caused increases in CSFP, equal to 89 +/- 31 % SE (p < 0.05) and 22 +/- 5% (p < 0.05), respectively. MAP decreased after administration of each opioid. Peak decreases in cerebral perfusion pressure (MAP - CSFP) were 14 +/- 3% after fentanyl, 25 +/- 5% after sufentanil, and 37 +/- 3% after alfentanil. It is concluded that because sufentanil increased CSFP in patients who have brain tumors, it also may be contraindicated in other neurosurgical patients at risk for intracranial hypertension. Alfentanil may share this propensity, since CSFP increased despite a profound reduction in MAP. Among the three opioids evaluated, only fentanyl appears to be appropriate for supplementing N2O-2 anesthesia in patients who have compromised intracranial compliance.

[The Polynesian connection: migration and social change in New Zealand and the South Pacific]

Un trait constant de la démographie néo-zélandaise depuis au moins 1 000 ans est la relation avec la Polynésie. Les flux de population entre les îles du Pacifique et la Nouvelle-Zélande se sont poursuivis tout au long des 130 années de peuplement et de domination européens. Quelques-uns des problèmes sociaux et économiques les plus urgents qui se posent aujourd'hui aux politiciens et aux aménageurs néo-zélandais concernent l'existence de cette société multiculturelle. Dans ce texte, on décrit à grands traits l'histoire de la migration polynésienne. Les perspectives (démographique, adaptation, dépendance structurelle) dégagées par les chercheurs en science sociale sont revues pour la période postérieure aux années 60. La conclusion aborde quelques problèmes pour l'avenir. Même si la Nouvelle- Zélande a aujourd'hui une économie en crise, elle est encore considérée par les Polynésiens comme une terre d'accueil. Le réseau très étendu de relations et de liens familiaux entre les Polynésiens résidant en Nouvelle-Zélande et ceux qui résident dans les îles nous amène à penser que la « Polynesian Connection » demeure très importante dans le Pacifique.