Benchmarking outcome in ICU

There are as yet few well developed systems for comparing the quality of care in Irish hospitals with other hospitals either nationally or internationally. The best known are the perinatal mortality rates of the Dublin maternity hospitals. Other examples include mortality rates after cardiac surgery and survival rates after cancer surgery. We describe a comparison of outcomes in an Irish ICU with internationally validated mortality rates for a given severity of illness. The method of stratifying for severity of illness is by use of the APACHE II scoring system. In 2003 the standardised mortality ratio for Beaumont Hospital ICU was 0.87 with a mean APACHE II admission score of 17.5 which compares favourably with similar data produced from UK units.

Changes in pharyngeal corticobulbar excitability and swallowing behavior after oral stimulation

Faucial pillar (FP) stimulation is commonly used in swallowing rehabilitation, yet its physiological basis remains uncertain. We investigated the effects of intraoral FP stimulation on human corticobulbar excitability and swallowing behavior, to explore the possibility of a central mechanism for functional change. In 10 healthy subjects, corticobulbar projections to pharynx were investigated with transcranial magnetic stimulation, via intraluminal electrodes, before and up to 1 h after 10 min of electrical FP stimulation with three frequencies (0.2, 1, and 5 Hz) or sham and peripheral (median nerve) stimulation. In a second study, swallowing behavior was assessed with videofluoroscopy before and after FP stimulation. FP stimulation at 5 Hz inhibited the corticobulbar projection (-14 +/- 6%, P < 0.02) and lengthened swallow response time (+114 +/- 24%, P = 0.02). By comparison, FP stimulation at 0.2 Hz facilitated this projection (+60 +/- 28%, P < 0.04), without enhancing swallowing behavior. Neither 1-Hz, sham, nor median nerve stimulation altered excitability. Thus changes in corticobulbar excitability to FP stimulation are frequency dependent with implications for the treatment for neurogenic swallowing dysfunction.

Expert consensus in the development of a European health-related quality of life measure for children and adolescents: a Delphi study

AIM

To determine the level of consensus among experts regarding content, structure and sources of content for a new European measure of health-related quality of life in children and adolescents.

METHODS

A three-round Delphi questionnaire was sent by e-mail to 24 experts in quality of life measurement in 9 European countries. Consensus was considered reached when > 90% of experts either agreed or disagreed with a given statement, or where median scores were over 6 on a scale of 1-10, and score dispersion was within predefined limits.

RESULTS

Completed questionnaires were received from 20 panellists in each round. It was agreed that the new instrument should be a multidimensional, profile measure with 30-49 items covering 5-8 dimensions, which should take no more than 10-15 min to complete. Agreement was also reached on 8 specific dimensions to include in the questionnaire (psychological well-being, self-esteem, body image, cognitive functioning, mobility, energy/vitality, social relations, family/home function). Consensus was against the use of individualized questionnaires. Focus groups with children, parents and workers in the field, literature and instrument reviews were considered appropriate sources for content.

CONCLUSION

Using a Delphi method in this way for the first time showed it to be a feasible and useful method for establishing a conceptual and operational framework for the Kidscreen questionnaire.

Modulation of human swallowing behaviour by thermal and chemical stimulation in health and after brain injury

Few data support thermal or chemical stimulation as therapy for neurogenic dysphagia. Our aims were to explore the behavioural effects of thermal (cold) and chemical (citrus) modalities on water swallowing in health (n = 65, mean age 45 years, 44 females) and acute stroke (n = 22, mean age 67 years, eight females). Multiple randomized timed 50-mL swallowing tests were performed for each of four water conditions: (a) room temperature (RT), (b) cold (CD), (c) citrus (CT) and (d) combined cold and citrus (CD + CT). The inter-swallow interval (ISI), swallowing volume velocity (speed), and volume per swallow (capacity) were measured. In health, compared to RT, only CD + CT slowed the speed (12.3 +/- 0.5 vs 10.3 +/- 0.5 mL s(-1), P < 0.03) and decreased the capacity (16.4 +/- 0.9 vs 14.6 +/- 0.7 mL per swallow, P < 0.02) of swallowing. ISI was unaffected, except by CD + CT in healthy young subjects (<60 years) where it was reduced (1.44 +/- 0.02 vs 1.30 +/- 0.02 s, P < 0.02). Despite smaller volumes ingested by stroke patients, CD + CT, compared to RT, again slowed both the speed (3.8 +/- 0.4 vs 4.5 +/- 0.5 mL s(-1), P < 0.03) and capacity (7.6 +/- 0.7 vs 8.5 +/- 0.7 mL per swallow, P < 0.03) of swallowing but had no effect on ISI. We conclude that combined thermal and chemical modification of water consistently alters swallowing behaviour in health and after cerebral injury. These findings have relevance in the management of neurogenic swallowing problems.

Validating methods for measuring delta18O and delta13C in otoliths from freshwater fish

The ability of the phosphoric acid digestion technique to extract carbon dioxide from biogenic carbonates and reliably reproduce delta(18)O and delta(13)C signatures from standard reference materials (NBS-18, NBS-19) was tested and shown to produce accurate, unbiased measurements of non-biologic materials. The effects of roasting preparation methods commonly reported when analyzing biogenic carbonates were also tested in a series of experiments using reference standards and otoliths obtained from aquacultured Arctic charr and rainbow trout. Roasting had no effect on the isotope measurement of reference standards. No significant differences between mean oxygen isotope signatures from paired experiments with roasted and non-roasted fish otoliths were found. However, otolith oxygen isotope measurements were significantly enriched in comparison to rearing water-based measurements for both species. Agreement between expected isotopic equilibrium and measured otolith delta(18)O values varied as a function of roasting temperature and between species. Criteria for the selection of appropriate roasting temperatures are suggested and favour 350 degrees C in freshwater fish where unbiased estimates of average rearing water temperatures and known differences in rearing temperatures were obtained. Carbon isotopic disequilibria were observed for both species. A mixing model analysis established differences in the percentage of metabolically derived carbon in studied otoliths, with Arctic charr deriving a greater proportion of otolith delta(13)C from metabolism as a result of higher metabolic rates.

Effects of temperature on isotopic enrichment in Daphnia magna: implications for aquatic food-web studies

Laboratory experiments were conducted with Daphnia magna and Hyalella sp. grown on a single food source of known isotopic composition at a range of temperatures spanning the physiological optima for each species. Daphnia raised at 26.5 degrees C were enriched in delta(13)C and delta(15)N by 3.1 and 2.8 per thousand, respectively, relative to diet. Daphnia raised at 12.8 degrees C were enriched 1.7 and 5.0 per thousand in delta(13)C and delta(15)N, respectively. Results imply a significant negative relationship between the delta(13)C and delta(15)N of primary consumers when a temperature gradient exists. Similar responses were observed for Hyalella. Results indicate a general increase in delta(13)C enrichment and decrease in delta(15)N enrichment as temperature rises. Deviations from the commonly applied isotopic enrichment values used in aquatic ecology were attributed to changes in temperature-mediated physiological rates. Field data from a variety of sources also showed a general trend toward delta(13)C enrichment with increasing temperature in marine and lacustrine zooplankton. Multivariate regression models demonstrated that, in oligotrophic and mesotrophic lakes, zooplankton delta(13)C was related to lake-specific POM delta(13)C, lake surface temperature and latitude. Temperature-dependent isotopic separation (enrichment) between predator and prey should be taken into consideration when interpreting the significance of isotopic differences within and among aquatic organisms and ecosystems, and when assigning organisms to food-web positions on the basis of observed isotope values.

Quality of life in children and adolescents: a European public health perspective

OBJECTIVES

The measurement of health-related quality of life (HRQOL) is increasingly important as a means of monitoring population health status over time, of detecting sub-groups within the general population with poor HRQOL, and of assessing the impact of public health interventions within a given population. At present, no standardised instrument exists which can be applied with equal relevance in pediatric populations in different European populations. The collaborative European KIDSCREEN project aims to develop a standardised screening instrument for children's quality of life which will be used in representative national and European health surveys. Participants of the project are centres from Austria, France, Germany, Netherlands, Spain, Switzerland, and United Kingdom. By including the instrument in health services research and health reporting, it also aims at identifying children at risk in terms of their subjective health, thereby allowing the possibility of early intervention.

METHODS

Instrument development will be based on constructing a psychometrically sound HRQOL instrument taking into account the existing state of the art. Development will centre on literature searches, expert consultation (Delphi Methods) and focus groups with children and adolescents (8-17 years). According to international guidelines, items will be translated into the languages of the seven participating countries for a pilot test with 2,100 children and their parents in Europe. The final instrument will be used in representative mail and telephone surveys of HRQOL in 1,800 children and their parents per country (total n = 25,200) and normative data will be produced. The potential for implementing the measurement tool in health services and health reporting will also be evaluated in several different research and public health settings. The final analysis will involve national and cross cultural-analysis of the instrument.

RESULTS

The international, collaborative nature of the KIDSCREEN project means it is likely to provide many challenges in terms of producing an instrument which is conceptually and linguistically appropriate for use in many different countries, but it will also provide the opportunity to develop, test and implement the first truly cross-national HRQOL instrument developed for use in children and adolescents. This will help to contribute to a better understanding of perceived health in children and adolescents and to identify populations at risk.

Survey of obstetrician-gynecologists in the United States about toxoplasmosis

Background: Although the incidence of toxoplasmosis is low in the United States, up to 6000 congenital cases occur annually. In September 1998, the Centers for Disease Control and Prevention held a conference about toxoplasmosis; participants recommended a survey of the toxoplasmosis-related knowledge and practices of obstetrician-gynecologists and the development of professional educational materials for them.

Methods: In the fall of 1999, surveys were mailed to a 2% random sample of American College of Obstetricians and Gynecologists (ACOG) members and to a demographically representative group of ACOGmembers known as the Collaborative Ambulatory Research Network (CARN). Responses were not significantly different for the random and CARN groups for most questions (p value shown when different).

Results: Among 768 US practicing ACOG members surveyed, 364 (47%) responded. Seven per cent (CARN 10%, random 5%) had diagnosed one or more case(s) of acute toxoplasmosis in the past year. Respondents were well-informed about how to prevent toxoplasmosis. However, only 12% (CARN 11%, random 12%) indicated that a positive Toxoplasma IgM test might be a false–positive result, and only 11% (CARN 14%, random 9%) were aware that the Food and Drug Administration sent an advisory to all ACOG members in 1997 stating that some Toxoplasma IgM test kits have high false–positive rates. Most of those surveyed (CARN 70%, random 59%; X²p < 0.05) were opposed to universal screening of pregnant women.

Conclusions: Many US obstetrician-gynecologists will encounter acute toxoplasmosis during their careers, but they are frequently uncertain about interpretation of the laboratory tests for the disease. Most would not recommend universal screening of pregnant women.

BACE knockout mice are healthy despite lacking the primary beta-secretase activity in brain: implications for Alzheimer's disease therapeutics

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by accumulation of amyloid plaques and neurofibrillary tangles in the brain. The major components of plaque, beta-amyloid peptides (Abetas), are produced from amyloid precursor protein (APP) by the activity of beta- and gamma-secretases. beta-secretase activity cleaves APP to define the N-terminus of the Abeta1-x peptides and, therefore, has been a long- sought therapeutic target for treatment of AD. The gene encoding a beta-secretase for beta-site APP cleaving enzyme (BACE) was identified recently. However, it was not known whether BACE was the primary beta-secretase in mammalian brain nor whether inhibition of beta-secretase might have effects in mammals that would preclude its utility as a therapeutic target. In the work described herein, we generated two lines of BACE knockout mice and characterized them for pathology, beta-secretase activity and Abeta production. These mice appeared to develop normally and showed no consistent phenotypic differences from their wild-type littermates, including overall normal tissue morphology and brain histochemistry, normal blood and urine chemistries, normal blood-cell composition, and no overt behavioral and neuromuscular effects. Brain and primary cortical cultures from BACE knockout mice showed no detectable beta-secretase activity, and primary cortical cultures from BACE knockout mice produced much less Abeta from APP. The findings that BACE is the primary beta-secretase activity in brain and that loss of beta-secretase activity produces no profound phenotypic defects with a concomitant reduction in beta-amyloid peptide clearly indicate that BACE is an excellent therapeutic target for treatment of AD.

One stop clinic for assessment of risk for fetal anomalies: a report of the first year of prospective screening for chromosomal anomalies in the first trimester

OBJECTIVE

To evaluate the introduction of a one stop multidisciplinary clinic for screening for fetal chromosomal abnormalities in the first trimester by a combination of maternal serum biochemistry and ultrasonography providing a risk of chromosomal abnormalities within a one hour clinic visit.

DESIGN

One year retrospective review of screening performance.

POPULATION

All women attending for routine antenatal care. The population included 4,190 singleton pregnancies in women of all ages screened between 10 weeks and 3 days and 13 weeks and 6 days of gestation between the periods 1 June 1998 and 31 May 1999 in a district general hospital antenatal clinic.

METHODS

All women booked into the clinic were offered screening by a combination of maternal serum free beta human chorionic gonadotrophin (hCG) and pregnancy associated plasma protein A (PAPP-A) and fetal nuchal translucency thickness. Women at increased risk of carrying a fetus with trisomy 21 or trisomy 18/13 (> or =1 in 300 at sampling) were offered counselling and an invasive diagnostic procedure. Follow up of the outcome of all pregnancies was carried out.

MAIN OUTCOME MEASURES

The detection rate for trisomy 21, trisomy 18/13 and all aneuploides, false positive rate, uptake of screening, uptake of chorionic villus sampling in women identified at increased risk and fetal loss after chorionic villus sampling.

RESULTS

Overall 97.6% of the women (4,088/4,190) accepted first trimester screening. The rate of detection of trisomy 21 was 86% (6/7), for trisomy 18/13 100% (9/9) and for all aneuploides 95% (18/19). Fetal death at presentation was found in 1.6% of pregnancies (69/4,088). Of women who accepted screening, 6.1% (257/4,088) presented too late for fetal nuchal translucency measurement and 6.5% of the women (271/4,088) presented too early. The false positive rate was 6.7% (253/3,762). Uptake of invasive testing was 83% (207/253).

CONCLUSION

First trimester prenatal screening for chromosomal abnormalities using a combination of maternal serum biochemistry and fetal nuchal translucency thickness can achieve detection rates in excess of 90%. These services can be provided in a one stop multidisciplinary clinic.

Obstetrician-gynecologists' opinions and attitudes on the role of genetics in women's health

Our objective was to describe gynecologists' current practice patterns and opinions on genetic screening and their perceived importance of genetic screening within individual practices. A questionnaire survey was sent to 1248 American College of Obstetrics and Gynecology (ACOG) Fellows, of whom 564 (45%) responded. Results from the 428 respondents providing genetic screening for heritable diseases or disorders are reported. Forty-four percent of respondents believe advances in the treatment of genetic diseases are likely in the next 10 years. Currently, however, genetics in gynecological practice receives infrequent attention. Twenty-four percent of respondents do not routinely review family histories at gynecological visits, 39% rate genetic issues as last among priorities in the office, and only 14% obtain consent for the DNA tests that they initiate. Although 21.3% identified themselves as sole providers of genetic information and counseling to their patients, most (65.4%) note they are not confident of their knowledge of genetics, particularly concerning breast and ovarian cancer. For obstetrician-gynecologists to keep pace with the rapid changes in genetics, further education and assimilation of genetics into the routine office practice will need to occur. Not currently viewed as a priority among practitioners, issues of genetic knowledge, ethics, and test interpretation will soon need attention. National organizations, continuing medical education, and existing genetic centers will need to meet these recognized demands.

Teaching critical appraisal during critical care fellowship training: a foundation for evidence-based critical care medicine

OBJECTIVE

To determine whether fellowship training in critical care medicine with critical appraisal exercises improves the ability and confidence of fellows to evaluate the medical literature.

DESIGN

Prospective, interventional pilot study.

SETTING

Multidisciplinary critical care medicine training program at a large university hospital.

INTERVENTION

Fellows were given three didactic sessions covering study design, analysis, and critical appraisal techniques. During the course of the year, each fellow was required to review one article from the literature and present a critique of this article to the group and faculty (Journal Club). Fellows were guided in the preparation of this presentation by one of the critical care medicine faculty. Finally, a written analysis and critique of the article was performed by each fellow.

MEASUREMENTS AND MAIN RESULTS

A test was given to each fellow at the beginning and end of the academic year. This test consisted of two pairs of articles on therapy for acute lung injury. For the pretest, each fellow was assigned, at random, one pair of articles. Fellows were given 1 hr to review both articles and to fill out a six-point test to assess their ability and confidence to appraise each article. At the end of the year, each fellow was tested on the opposite pair, the tests were graded in a blinded fashion and the results of each test were compared. Six fellows completed both pre- and posttests. These paired results were analyzed separately, whereas results for another six fellows were conducted as an unpaired analysis. Mean scores increased both for the paired analysis (4.1+/-0.7 vs. 5.1+/-0.5; p = .015) and for the unpaired analysis (4.3+/-0.6 vs. 5.0+/-0.5; p = .012). Self-reported confidence in critical appraisal also increased (2.5+/-0.5 vs. 3.9+/-0.7; p = .004 and 2.6+/-0.5 vs. 3.9+/-0.6; p < .001, respectively).

CONCLUSION

Critical appraisal exercises used in the training of critical care medicine fellows appear to improve both ability and confidence to appraise relevant medical literature.

Disease and gill lesions in yellow perch (Perca flavescens) exposed to oil sands mining-associated waters

Adult yellow perch were stocked into experimental ponds designed to test the biological effects of aquatic reclamation alternatives currently being pursued by the oil sands mining industry. Water-quality characteristics of oil sands-influenced water in the experimental ponds included increased salinity and elevated trace organics associated with raw oil sands (bitumen). After 3 and 10 months of exposure to affected waters, perch gross pathologies including severe fin erosion and virally induced tumors were observed in exposed individuals. Gill histopathology revealed large aneurysms accompanied by a proliferation of chloride and epithelial cells in the interlamellar spaces. Gill pathologies were not paralleled by a decrease in plasma sodium, calcium, or chloride. The frequencies of gross pathologies and gill changes were correlated to the concentrations of the oil sands-related compounds. As inorganic and organic compounds associated with oil sands activities are highly intercorrelated, and the observed lesions and changes are not diagnostic of particular toxicants, it was not possible to isolate the causative chemical factor(s) responsible. The incidence of observed lesions and gill pathologies could not be conclusively linked to increased mortality rates observed in the exposed populations. Evidence of recovery in the pathologies was observed between 3 and 10 months of exposure, coincident with a stabilization in population numbers.

Childhood trauma, dissociation and self-harming behaviour: a pilot study

OBJECTIVE

Childhood trauma is known to be an important antecedent in those who engage in deliberate self-harm (DSH). We aimed to explore the mediating mechanisms between childhood trauma and subsequent DSH in a sample of women detained in a high secure setting.

METHOD

From a previous incidence study into DSH, we subdivided a group of 50 women as follows: non-harmers (N = 13), infrequent harmers (N = 22) and frequent harmers (N = 15). These three groups were then compared on several measures believed to be associated with DSH.

RESULTS

The frequency of DSH was related to low self-esteem, increased dissociation, anger (both inwardly and outwardly directed), impulsivity, and a history of sexual and physical abuse. When these variables were entered into a path analytic model exploring the relationship between childhood trauma and subsequent DSH, two paths emerged: one major path which linked childhood sexual abuse to DSH via increased dissociation and another, more minor association, linking childhood sexual abuse via reduced self-esteem.

CONCLUSION

This study shows a strong association between high levels of dissociation and an increased frequency of self-harming behaviour. This association is theoretically plausible and has therapeutic implications.

The World Health Organization WHOQOL-100: tests of the universality of Quality of Life in 15 different cultural groups worldwide

The World Health Organization Quality of Life assessment (WHOQOL-100) was developed simultaneously across 15 international field centers and includes 24 facets relating to quality of life, which are grouped into 4 larger domains: physical, psychological, social relationships, and environment. It also includes 1 facet examining overall quality of life and general health perceptions. This article examines the extent to which the WHOQOL-100 assesses quality of life perceptions in different cultures and whether it is structurally comparable in these cultures. Regression analysis showed all 4 domains to be important in assessing quality of life in each of the 15 centers. Structural equation modeling suggested further support for the proposal that there are universal facets and domains that are cross-culturally important in determining quality of life and suggested that the ordering of facets within domains is comparable across cultures.

Purification and cloning of amyloid precursor protein beta-secretase from human brain

Proteolytic processing of the amyloid precursor protein (APP) generates amyloid beta (Abeta) peptide, which is thought to be causal for the pathology and subsequent cognitive decline in Alzheimer's disease. Cleavage by beta-secretase at the amino terminus of the Abeta peptide sequence, between residues 671 and 672 of APP, leads to the generation and extracellular release of beta-cleaved soluble APP, and a corresponding cell-associated carboxy-terminal fragment. Cleavage of the C-terminal fragment by gamma-secretase(s) leads to the formation of Abeta. The pathogenic mutation K670M671-->N670L671 at the beta-secretase cleavage site in APP, which was discovered in a Swedish family with familial Alzheimer's disease, leads to increased beta-secretase cleavage of the mutant substrate. Here we describe a membrane-bound enzyme activity that cleaves full-length APP at the beta-secretase cleavage site, and find it to be the predominant beta-cleavage activity in human brain. We have purified this enzyme activity to homogeneity from human brain using a new substrate analogue inhibitor of the enzyme activity, and show that the purified enzyme has all the properties predicted for beta-secretase. Cloning and expression of the enzyme reveals that human brain beta-secretase is a new membrane-bound aspartic proteinase.

An approach to policy analysis and development of medical informatics

There are three grand challenges for medical informatics policy: (1) What is it? (2) What should it be? (3) How can we influence its development? To address these challenges requires: (1) an historical analysis of medical informatics policies in a representative sample of countries. This should include an account of major events, the roles of technology, individuals, culture and social settings. Pioneers have been led by visions of what medical informatics should achieve. The role of these visions and the reactions to unmet expectations thus also need to be analysed; (2) a generally applicable medical informatics policy that places the needs of its stakeholders and clients first. Top priorities are to support quality health care delivery and quality management of health care facilities; (3) an explanation of how policies in medical informatics are created and implemented together with a strategy to guide medical informatics professionals in their lobbying efforts.

The World Health Organization WHOQOL-100: tests of the universality of Quality of Life in 15 different cultural groups worldwide

The World Health Organization Quality of Life assessment (WHOQOL-100) was developed simultaneously across 15 international field centers and includes 24 facets relating to quality of life, which are grouped into 4 larger domains: physical, psychological, social relationships, and environment. It also includes 1 facet examining overall quality of life and general health perceptions. This article examines the extent to which the WHOQOL-100 assesses quality of life perceptions in different cultures and whether it is structurally comparable in these cultures. Regression analysis showed all 4 domains to be important in assessing quality of life in each of the 15 centers. Structural equation modeling suggested further support for the proposal that there are universal facets and domains that are cross-culturally important in determining quality of life and suggested that the ordering of facets within domains is comparable across cultures.

Applications of comparative genomic hybridisation in constitutional chromosome studies

G band cytogenetic analysis often leads to the discovery of unbalanced karyotypes that require further characterisation by molecular cytogenetic studies. In particular, G band analysis usually does not show the chromosomal origin of small marker chromosomes or of a small amount of extra material detected on otherwise normal chromosomes. Comparative genomic hybridisation (CGH) is one of several molecular approaches that can be applied to ascertain the origin of extra chromosomal material. CGH is also capable of detecting loss of material and thus is also applicable to confirming or further characterising subtle deletions. We have used comparative genomic hybridisation to analyse 19 constitutional chromosome abnormalities detected by G band analysis, including seven deletions, five supernumerary marker chromosomes, two interstitial duplications, and five chromosomes presenting with abnormal terminal banding patterns. CGH was successful in elucidating the origin of extra chromosomal material in 10 out of 11 non-mosaic cases, and permitted further characterisation of all of the deletions that could be detected by GTG banding. CGH appears to be a useful adjunct tool for either confirming deletions or defining their breakpoints and for determining the origin of extra chromosomal material, even in cases where abnormalities are judged to be subtle. We discuss internal quality control measures, such as the mismatching of test and reference DNA in order to assess the quality of the competitive hybridisation effect on the X chromosome.

Recovery of swallowing after dysphagic stroke relates to functional reorganization in the intact motor cortex

BACKGROUND & AIMS

The aim of this study was to determine the mechanism for recovery of swallowing after dysphagic stroke.

METHODS

Twenty-eight patients who had a unilateral hemispheric stroke were studied 1 week and 1 and 3 months after the stroke by videofluoroscopy. Pharyngeal and thenar electromyographic responses to magnetic stimulation of multiple sites over both hemispheres were recorded, and motor representations were correlated with swallowing recovery.

RESULTS

Dysphagia was initially present in 71% of patients and in 46% and 41% of the patients at 1 and 3 months, respectively. Cortical representation of the pharynx was smaller in the affected hemisphere (5 +/- 1 sites) than the unaffected hemisphere (13 +/- 1 sites; P </= 0.001). Nondysphagic and persistently dysphagic patients showed little change in pharyngeal representation in either hemisphere at 1 and 3 months compared with presentation, but dysphagic patients who recovered had an increased pharyngeal representation in the unaffected hemisphere at 1 and 3 months (15 +/- 2 and 17 +/- 3 vs. 9 +/- 2 sites; P </= 0.02) without change in the affected hemisphere. In contrast, thenar representation increased in the affected hemisphere but not the unaffected hemisphere at 1 and 3 months (P </= 0.01).

CONCLUSIONS

Return of swallowing after dysphagic stroke is associated with increased pharyngeal representation in the unaffected hemisphere, suggesting a role for intact hemisphere reorganization in recovery.

Distinct subdomains of the EphA3 receptor mediate ligand binding and receptor dimerization

Eph receptor tyrosine kinases and their ligands (ephrins) are highly conserved protein families implicated in patterning events during development, particularly in the nervous system. In a number of functional studies, strict conservation of structure and function across distantly related vertebrate species has been confirmed. In this study we make use of the observation that soluble human EphA3 (HEK) exerts a dominant negative effect on somite formation and axial organization during zebrafish embryogenesis to probe receptor function. Based on exon structure we have dissected the extracellular region of EphA3 receptor into evolutionarily conserved subdomains and used kinetic BIAcore analysis, mRNA injection into zebrafish embryos, and receptor transphosphorylation analysis to study their function. We show that ligand binding is restricted to the N-terminal region encoded by exon III, and we identify an independent, C-terminal receptor-dimerization domain. Recombinant proteins encoding either region in isolation can function as receptor antagonists in zebrafish. We propose a two-step mechanism of Eph receptor activation with distinct ligand binding and ligand-independent receptor-receptor oligomerization events.

Growth variation in common marmoset monkeys (Callithrix jacchus) fed a purified diet: relation to care-giving and weaning behaviors

Significant relations were observed between select infant-care and weaning behaviors and growth in body weight in common marmoset monkeys (Callithrix jacchus). The patterns of these relations suggest that earlier occurrence of developmental milestones, such as cessation of transport (being off carriers) and weaning to solid food, were associated with slower growth during the subsequent period. In contrast, more frequent nursing bouts during the period in which weaning was initiated were associated with higher growth rates. In the case of being off carriers, these effects did not carry over to older ages, suggesting that any deficits in growth were temporary. In the case of earlier, more frequent consumption of solid food, there was some suggestion that there were longer-term effects, followed by catch-up growth. The knee-to-heel length of subjects was not related to the measured behaviors. There was no relation between early weaning to solid food and leanness at day 75, suggesting that, although this behavior was affecting overall weight, it did not affect relative gains of fat versus lean mass. There were, however, significant correlations between cessation of transport or frequency of nursing bouts during the weaning period and leanness, with earlier cessation of transport and less frequent nursing associated with leaner infants, after weaning. Our results differed from those of a previous study that found a relation between linear growth and abuse in this species, with abuse defined as physical injury by other members of the group. We found no differences in growth between abused and nonabused infants. However, abused infants had lower birth weight.

Tolerance and pharmacokinetic interactions of rifabutin and clarithromycin in human immunodeficiency virus-infected volunteers

This study evaluated the tolerance and potential pharmacokinetic interactions between clarithromycin (500 mg every 12 h) and rifabutin (300 mg daily) in clinically stable human immunodeficiency virus-infected volunteers with CD4 counts of <200 cells/mm3. Thirty-four subjects were randomized equally to either regimen A or regimen B. On days 1 to 14, subjects assigned to regimen A received clarithromycin and subjects assigned to regimen B received rifabutin, and then both groups received both drugs on days 15 to 42. Of the 14 regimen A and the 15 regimen B subjects who started combination therapy, 1 subject in each group prematurely discontinued therapy due to toxicity, but 19 of 29 subjects reported nausea, vomiting, and/or diarrhea. Pharmacokinetic analysis included data for 11 regimen A and 14 regimen B subjects. Steady-state pharmacokinetic parameters for single-agent therapy (day 14) and combination therapy (day 42) were compared. Regimen A resulted in a mean decrease of 44% (P = 0.003) in the clarithromycin area under the plasma concentration-time curve (AUC), while there was a mean increase of 57% (P = 0.004) in the AUC of the clarithromycin metabolite 14-OH-clarithromycin. Regimen B resulted in a mean increase of 99% (P = 0.001) in the rifabutin AUC and a mean increase of 375% (P < 0.001) in the AUC of the rifabutin metabolite 25-O-desacetyl-rifabutin. The usefulness of this combination for prophylaxis of Mycobacterium avium infections is limited by frequent gastrointestinal adverse events. Coadministration of clarithromycin and rifabutin results in significant bidirectional pharmacokinetic interactions. The resulting increase in rifabutin levels may explain the increased frequency of uveitis observed with concomitant use of these drugs.

Turner syndrome: a cytogenetic and molecular study

Two hundred and eleven patients with a clinical diagnosis of Turner syndrome were studied. We report (i) the cytogenetic results, (ii) the frequency of cryptic mosaicism and (iii) the parental age and the parental origin of the abnormality. We scored 100 cells from blood cultures and found 97 patients to have a 45,X constitution, 15 to be 45,X/46,XX or 45,X/47,XXX mosaics, 86 to have a structurally abnormal X and 13 to have a structurally abnormal Y chromosome. Molecular methods were used to look for cryptic X and Y chromosome mosaicism in patients with a 45,X constitution. Two cryptic X but no cryptic Y mosaics were detected. In 74% of the 45,X patients the X was maternal in origin. The i(Xq)s were approximately equally likely to involve the paternal or maternal chromosome, while the majority of deletions and rings and virtually all the abnormal Y chromosomes were paternal in origin. We suggest that the preponderance of paternal errors in Turner syndrome may result from the absence of pairing along the greater part of the XY bivalent during paternal mei I, which may make the sex chromosomes particularly susceptible to both structural and non-disjunctional errors during male gametogenesis.

SPECIAL SECTION: Perspectives of the Scientific Community on the Status of Ecological Risk Assessment

/ Views from a wide variety of practicing environmental professionals on the current status of ecological risk assessment (ERA) indicate consensus and divergence of opinion on the utility and practice of risk assessment. Central to the debate were the issues of whether ERA appropriately incorporates ecological and scientific principle into its conceptual paradigm. Advocates argue that ERA effectively does both, noting that much of the fault detractors find with the process has more to do with its practice than its purpose. Critics argue that failure to validate ERA predictions and the tendency to over-simplify ecological principles compromise the integrity of ERA and may lead to misleading advice on the appropriate responses to environmental problems. All authors felt that many improvements could be made, including validation, better definition of the ecological questions and boundaries of ERA, improved harmonization of selected methods, and improvements in the knowledge base. Despite identified deficiencies, most authors felt that ERA was a useful process undergoing evolutionary changes that will inevitably determine the range of environmental problems to which it can be appropriately applied. The views expressed give ERA a cautious vote of approval and highlight many of the critical strengths and weaknesses in one of our most important environmental assessment tools.KEY WORDS: Ecological risk assessment; Ecology; Probability

Most patients attending a 'walk-in' clinic at Red Cross War Memorial Children's Hospital could safely be managed at primary care level

OBJECTIVES

(i) To ascertain what proportion of patients attending the general medical outpatient service at Red Cross War Memorial Children's Hospital (RXH) could safely be managed at peripheral primary care facilities; and (ii) to measure the effect of the introduction of free health care for children under 6 years of age on requirements for levels of care ranging from home to super-specialist referral centres.

DESIGN

Prospective survey of patients attending on a stratified, randomised sample of 7 days in March 1994 (N = 1 962) and again in November 1994 (N = 1 404)-before and after the introduction on 6 June 1994 of free care for children under 6 years of age.

SETTING

The general outpatient department of an academic/referral children's hospital.

PATIENT SELECTION

All patients attending the outpatient department on the study days (7h00 to 6h59 the following day), excluding those who were referred, returning for follow-up, attending a specialist clinic or attending the surgical outpatient department. QUESTIONNAIRE: The questionnaire completed by medical officers recorded the following: patient's name, folder number, date and time of arrival, whether referred, clinic, treating doctor, disposal, diagnoses, home suburb and the level of care required: (i) home: (ii) clinic without a doctor; (iii) clinic with a doctor; (iv) hospital with non-specialists; (v) hospital with general paediatricians; or (vi) super-specialist hospital.

MAIN RESULTS

In March 1994 the percentages of unreferred patients requiring the 6 levels of care defined for the study were 0.3, 25, 62, 8, 3 and 1, respectively. In November 1994 the percentages were 4, 41, 43, 8, 4 and 1. The graph of the number of patients seen at the outpatient department each month shows a large month-to-month variation but the trend is clearly towards an increase.

CONCLUSIONS

The general medical outpatient department at RXH provides care to a large number of children, 48% of whom are unreferred. Of the unreferred patients 95% could be treated (more appropriately for the health services and more conveniently for their families) at a local primary health care facility. The situation has been aggravated by the introduction of free care for children under 6 years of age, who constitute 83% of the unreferred workload.

Social support in patients with anorexia nervosa and bulimia nervosa

OBJECTIVE

To investigate the social support networks of patients with anorexia nervosa (AN) and bulimia nervosa (BN).

METHOD

Social support was measured using the Significant Others Scale for 44 patients with AN, 81 patients with BN, and 86 polytechnic students.

RESULTS

Eating disorder patients had smaller social networks than the students. AN patients were significantly less likely than BN patients to have a spouse or partner as a support figure. Both AN and BN patients reported less actual emotional and practical support than students. AN patients perceived their social support to be adequate, whereas BN patients were dissatisfied with their support. Patients set lower ideals for support than the students. Social support was not correlated with duration of illness.

DISCUSSION

AN and BN patients have deficient social networks. In BN patients there is disturbance in both the size and perceived adequacy of social relationships.

Levels and alternative splicing of amyloid beta protein precursor (APP) transcripts in brains of APP transgenic mice and humans with Alzheimer's disease

Abnormal expression of human amyloid precursor protein (hAPP) gene products may play a critical role in Alzheimer's disease (AD). Recently, a transgenic model was established in which platelet-derived growth factor (PDGF) promoter-driven neuronal expression of an alternatively spliced hAPP minigene resulted in prominent AD-type neuropathology (Games, D., Adams, D., Alessandrini, R., Barbour, R., Berthelette, P., Blackwell, C., Carr, T., Clemens, J., Donaldson, T., Gillespie, F., Guido, T., Hagopian, S., Johnson-Wood, K., Khan, K., Lee, M., Leibowitz, P., Lieberburg, I., Little, S., Masliah, E., McConlogue, L., Montoya-Zavala, M., Mucke, L., Paganini, L., and Penniman, E. (1995) Nature 373, 523-527). Here we compared the levels and alternative splicing of APP transcripts in brain tissue of hAPP transgenic and nontransgenic mice and of humans with and without AD. PDGF-hAPP mice showed severalfold higher levels of total APP mRNA than did nontransgenic mice or humans, whereas their endogenous mouse APP mRNA levels were decreased. This resulted in a high ratio of mRNAs encoding mutated hAPP versus wild-type mouse APP. Modifications of hAPP introns 6, 7, and 8 in the PDGF-hAPP construct resulted in a prominent change in alternative splice site selection with transcripts encoding hAPP770 or hAPP751 being expressed at substantially higher levels than hAPP695 mRNA. Frontal cortex of humans with AD showed a subtle increase in the relative abundance of hAPP751 mRNA compared with normal controls. These data identify specific intron sequences that may contribute to the normal neuronspecific alternative splicing of APP pre-mRNA in vivo and support a causal role of hAPP gene products in the development of AD-type brain alterations.

Perinatal mortality in the Cape Province, 1989-1991

OBJECTIVE

To determine the number of deliveries, the low-birth-weight rate and the perinatal mortality rate at provincial and province-aided hospitals and clinics in each planning region of the Cape Province.

DESIGN

A record of the number of deliveries, low-birth-weight infants, stillbirths and early neonatal deaths in provincial and province-aided hospitals and clinics in each planning region of the Cape Province between 1 January 1989 and 31 December 1991.

SETTING

All provincial and province-aided hospitals and clinics in the Cape Province.

PARTICIPANTS

Hospital and clinic staff of all provincial and province-aided hospitals and clinics in the Cape Province.

MAIN OUTCOMES MEASURED

Number of deliveries, low-birth-weight infants, stillbirths and early neonatal deaths in each planning region of the Cape Province.

RESULTS

A total of 373,768 births were recorded during the 3-year period with a low-birth-weight rate of 14.7%, a stillbirth rate of 17.9 per 1,000 and an early neonatal mortality rate of 9.1 per 1,000. All rates differed widely between regions. The regions with the highest perinatal mortality rates were in the northern and eastern Cape.

CONCLUSION

The perinatal demographics of most regions in the Cape Province are typical of a developing country. Regions which have been identified as having the highest low-birth-weight, stillbirth and early neonatal mortality rates are in greatest need of improved perinatal health care.

Phase II dose-ranging trial of foscarnet salvage therapy for cytomegalovirus retinitis in AIDS patients intolerant of or resistant to ganciclovir (ACTG protocol 093). AIDS Clinical Trials Group of the National Institute of Allergy and Infectious Diseases

OBJECTIVE

To document response to foscarnet salvage therapy in patients with cytomegalovirus (CMV) retinitis who are intolerant of or resistant to ganciclovir.

METHODS

Patients with AIDS and CMV retinitis who had documented hematologic intolerance or resistance to ganciclovir therapy received an induction course of foscarnet, 60 mg/kg every 8 h for 14 days, and subsequent chronic maintenance foscarnet therapy at a daily dose of 60, 90 or 120 mg/kg/day. The first 87 patients were randomly assigned to receive maintenance foscarnet at a dose of 60 or 90 mg/kg/day; all subsequent patients were assigned a maintenance dose of 120 mg/kg/day.

RESULTS

A total of 156 evaluable patients were enrolled. Median time to retinitis progression and survival did not differ significantly among groups assigned to different maintenance foscarnet doses. Among patients with retinitis progression documented ophthalmologically occurring at < or = 2 week intervals, despite optimal doses of ganciclovir, time to progression on foscarnet therapy was a median 8 weeks at all doses studied. By dose assignment, there were no significant differences in serious drug-associated toxicity, although trends toward increased renal and hypocalcemic adverse events were observed at higher maintenance doses.

CONCLUSION

In patients intolerant of ganciclovir, salvage foscarnet therapy resulted in a longer time to retinitis progression than reported previously in historic controls who terminated ganciclovir therapy. In patients who exhibited clinical resistance to ganciclovir, foscarnet appeared to have efficacy in controlling retinitis. No significant differences in either efficacy or toxicity were observed in the range of foscarnet maintenance doses studied.

Patient response to laryngeal mask insertion after induction of anaesthesia with propofol or thiopentone

The response to insertion of the laryngeal mask airway (LMA) following either propofol 2.5 mg.kg-1 or thiopentone 5 mg.kg-1 was assessed in two groups of patients. The purpose of the study was to ascertain which of these two induction agents provided the better conditions for insertion of the LMA. Anaesthesia was induced by propofol in 35 patients and by thiopentone in 37. Following induction, ventilation was assisted for two minutes using 50% oxygen and nitrous oxide and 2% isoflurane, before insertion of the LMA. The presence of gagging, coughing, laryngospasm and movement was noted and graded. Thiopentone was associated with an adverse response in 76% of patients, compared with propofol in 26% (P < 0.01). Gagging, laryngospasm and head movement were more common using thiopentone (P < 0.01, P < 0.05 and P < 0.05 respectively) and in 11% (P < 0.05) of the thiopentone group insertion of the LMA was impossible due to inadequate relaxation. We conclude that, using these doses, propofol is superior to thiopentone as an induction agent for insertion of the laryngeal mask airway.