Host learning selects for the coevolution of greater egg mimicry and narrower antiparasitic egg-rejection thresholds

Egg rejection is an effective and widespread antiparasitic defense to eliminate foreign eggs from the nests of hosts of brood parasitic birds. Several lines of observational and critical experimental evidence support a role for learning by hosts in the recognition of parasitic versus own eggs; specifically, individual hosts that have had prior or current experience with brood parasitism are more likely to reject foreign eggs. Here we confirm experimentally the role of prior experience in altering subsequent egg-rejection decisions in the American robin Turdus migratorius, a free-living host species of an obligate brood parasite, the brown-headed cowbird Molothrus ater. We then model the coevolutionary trajectory of both the extent of mimicry of host eggs by parasitic eggs and the host's egg rejection thresholds in response to an increasing role of learning in egg recognition. Critically, with more learning, we see the evolution of both narrower (more discriminating) rejection thresholds in hosts and greater egg mimicry in parasites. Increasing host clutch size (number of eggs/nest) and increasing parasite load (parasitism rate) also have narrowing effects on the egg-rejection threshold. Together, these results suggest that learning from prior experience with egg rejection may play an important role in the coevolution of egg-mimetic lineages of brood parasites and the refined egg rejection defenses of hosts.

Non-invasive elevation of circulating corticosterone increases the rejection of foreign eggs in female American robins (Turdus migratorius)

Avian obligate brood parasites rely on other species to raise their offspring. In turn, many brood parasite hosts have evolved defensive behaviors to reduce the costs of brood parasitism, yet the proximate bases underlying these defenses remain poorly understood. Recent studies regarding the potential endocrine mechanisms of foreign-egg rejection have implicated corticosterone as a physiological mediator of anti-parasitic defenses. For example, corticosterone is elevated in response to non-mimetic eggs in an egg rejecter thrush, the Eurasian blackbird (Turdus merula) and this hormone's suppression reduces egg rejection rates in the congeneric American robin (T. migratorius). American robins are also among the few host species of obligate brood parasitic brown-headed cowbirds (Molothrus ater) that readily reject foreign eggs from their nests. We non-invasively elevated corticosterone levels in incubating female robins by dissolving it in DMSO gel which was then applied onto eggs already in the clutch. Relative to controls treated with pure DMSO gel, corticosterone-treated female robins were more likely to reject a non-mimetic, cowbird-sized foreign egg (72 %) than control females (50 %) when accounting for the known effect of lower clutch sizes on greater egg rejection. Future studies are needed to assess the sensory and cognitive impact(s) of corticosterone, as well as other hormones essential for parental care, in this and other hosts' defense behaviors against avian brood parasitism.

Unique and shared systemic biomarkers for emphysema in Alpha-1 Antitrypsin deficiency and chronic obstructive pulmonary disease

BACKGROUND

Alpha-1 Antitrypsin (AAT) deficiency (AATD), the most common genetic cause of emphysema presents with unexplained phenotypic heterogeneity in affected subjects. Our objectives to identify unique and shared AATD plasma biomarkers with chronic obstructive pulmonary disease (COPD) may explain AATD phenotypic heterogeneity.

METHODS

The plasma or serum of 5,924 subjects from four AATD and COPD cohorts were analyzed on SomaScan V4.0 platform. Using multivariable linear regression, inverse variance random-effects meta-analysis, and Least Absolute Shrinkage and Selection Operator (LASSO) regression we tested the association between 4,720 individual proteins or combined in a protein score with emphysema measured by 15th percentile lung density (PD15) or diffusion capacity (DLCO) in distinct AATD genotypes (Pi*ZZ, Pi*SZ, Pi*MZ) and non-AATD, PiMM COPD subjects. AAT SOMAmer accuracy for identifying AATD was tested using receiver operating characteristic curve analysis.

FINDINGS

In PiZZ AATD subjects, 2 unique proteins were associated with PD15 and 98 proteins with DLCO. Of those, 68 were also associated with DLCO in COPD also and enriched for three cellular component pathways: insulin-like growth factor, lipid droplet, and myosin complex. PiMZ AATD subjects shared similar proteins associated with DLCO as COPD subjects. Our emphysema protein score included 262 SOMAmers and predicted emphysema in AATD and COPD subjects. SOMAmer AAT level <7.99 relative fluorescence unit (RFU) had 100% sensitivity and specificity for identifying Pi*ZZ, but it was lower for other AATD genotypes.

INTERPRETATION

Using SomaScan, we identified unique and shared plasma biomarkers between AATD and COPD subjects and generated a protein score that strongly associates with emphysema in COPD and AATD. Furthermore, we discovered unique biomarkers associated with DLCO and emphysema in PiZZ AATD.

FUNDING

This work was supported by a grant from the Alpha-1 Foundation to RPB. COPDGene was supported by Award U01 HL089897 and U01 HL089856 from the National Heart, Lung, and Blood Institute. Proteomics for COPDGene was supported by NIH 1R01HL137995. GRADS was supported by Award U01HL112707, U01 HL112695 from the National Heart, Lung, and Blood Institute, and UL1TRR002535 to CCTSI; QUANTUM-1 was supported by the National Heart Lung and Blood Institute, the Office of Rare Diseases through the Rare Lung Disease Clinical Research Network (1 U54 RR019498-01, Trapnell PI), and the Alpha-1 Foundation. COPDGene is also supported by the COPD Foundation through contributions made to an Industry Advisory Board that has included AstraZeneca, Bayer Pharmaceuticals, Boehringer-Ingelheim, Genentech, GlaxoSmithKline, Novartis, Pfizer, and Sunovion.

Eggshell texture but not odor treatment affects model egg rejection in American robins (Turdus migratorius)

To curb fitness costs associated with obligate avian brood parasitism, some hosts have evolved to reject foreign eggs in the nest. American robins (Turdus migratorius) are among the few hosts of the brown-headed cowbird (Molothrus ater) that mostly remove parasitic eggs from their nests. With the parasite's eggs looking nothing like their own, American robins likely rely most on visual cues when making rejection decisions. However, we still know little about the roles that tactile and olfactory cues play in robin's or other rejecter hosts' rejection decisions. Here, we conducted a set of experiments to test for the use of tactile or olfactory cues in egg rejection by robins. For the tactile experiment, we found that robins were more likely to reject rough rather than smooth eggs. However, our tactile model egg design was not able to fully discriminate between tactile and visual sensory modalities. In the olfaction experiment, we did not find a significant effect of egg scent treatment on rejection rates. Accordingly, future studies on egg rejection should attempt to fully distinguish between tactile and visual cues, as well as examine olfactory cues in other egg rejecter host species.

Systematic review: the natural history of alpha-1 antitrypsin deficiency, and associated liver disease

BACKGROUND

Alpha-1 antitrypsin deficiency (AATD) is estimated to affect three million people worldwide. It causes liver disease in a proportion of carriers of the PiS and PiZ allele due to the formation and retention of polymers within the endoplasmic reticulum of hepatocytes. The reason for this selective penetrance is not known. Although clinical trials are underway, liver transplantation is the only effective treatment for liver disease due to AATD.

AIMS

To report the prevalence and natural history of liver disease among individuals with AATD, and assess the outcomes of liver transplantation through systematic review.

METHODS

A comprehensive search was conducted across multiple databases. Two independent authors selected the articles and assessed bias using the Newcastle-Ottawa Scale. Data were pooled for analysis, where comparable outcomes were reported.

RESULTS

Thirty-five studies were identified related to disease progression and 12 for the treatment of AATD. Seven per cent of children were reported to develop liver cirrhosis, with 16.5% of individuals presenting in childhood requiring liver transplantation. Of those surviving to adulthood, 10.5% had liver cirrhosis and 14.7% required transplantation. Liver transplantation was the only effective treatment reported and outcomes compare favourably to other indications, with 5-year survival reported as over 90% in children and over 80% in adults.

DISCUSSION

The clinical course of liver disease in individuals with AATD remains poorly understood, but affects about 10% of those with AATD. More research is required to identify those patients at risk of developing liver disease at an early stage, and to provide alternative treatments to liver transplantation.

Understanding views on everyday use of personal health information: Insights from community dwelling older adults

BACKGROUND

Older adults apply various strategies to pursue healthy aging, but we know little about their views and use of personal health information to accomplish those ends.

METHODS

As a first step in formulating the role of personal health information management (PHIM) in healthy aging, we explored the perspectives of older adults on health and health information used in their everyday lives through four focus groups with 25 community-dwelling adults aged 60 and over.

RESULTS

We found that the concept of wellness-the holistic and multidimensional nature of health and wellbeing-plays prominently in how older adults think about health and health information. Participants expressed wellness from a position of personal strength, rather than health-related deficits, by focusing on wellness activities for staying healthy through: (1) personal health practices, (2) social network support, and (3) residential community engagement.

CONCLUSION

Although these themes involve personal health information, existing PHIM systems that focus on disease management are generally not designed to support wellness activities. Substantial opportunity exists to fill this wellness support gap with innovative health information technology designed for older adults. Findings carry implications for the design of PHIM tools that support healthy aging and methods for engaging older adults as co-producers of this critical support.

A care-bundles approach to improving standard of care in AECOPD admissions: results of a national project

This report describes a care bundles implementation project for COPD undertaken during 2013 in England and Wales. High-level data were collected on outcomes of care for 11 748 patients admitted with an acute exacerbation of COPD (AECOPD). Patient-level data on processes and outcomes of care were collected on 3272 COPD admissions, among which 1174 bundles were delivered. Analysis demonstrated a statistically significant reduction in mortality and length of hospital stay from some bundle elements. Outcomes, including bundle completion rates, were better when specialist respiratory review occurred. The results support wider use of care bundles for AECOPD.

PiSZ alpha-1 antitrypsin deficiency (AATD): pulmonary phenotype and prognosis relative to PiZZ AATD and PiMM COPD

INTRODUCTION

The PiSZ genotype results in less severe deficiency of alpha-1 antitrypsin (AAT) than PiZZ. Less is known about phenotypic and prognostic features.

METHODS

We studied 699 PiZZ, 126 PiSZ and 316 PiMM patients. All AAT deficiency (AATD) patients were augmentation naive. PiSZ were compared with PiZZ patients for clinical phenotype at baseline including CT findings, smoke exposure, progression of lung disease and survival. Similarly, PiSZ patients diagnosed as a result of investigation for possible lung disease (lung index cases) were compared with PiMM. Multivariable analytical techniques and matching (PiSZ to PiZZ) were employed to account for demographic differences.

RESULTS

Pack-years smoked and FEV1 exhibited a negative correlation in PiSZ and ZZ patients (both r=-0.43), with emphysema and COPD occurring more commonly in PiZZ patients at <20 pack-year exposure. In multivariable analyses, PiSZ patients were less likely to have emphysema (p<0.01) and had better survival than PiZZ (p=0.017), but lung function decline did not differ significantly. 42% of PiSZ patients had upper-zone-dominant emphysema on CT scan. Analyses of AAT level confirmed a critical threshold at 11 μM, particularly with regard to phenotypes classical of PiZZ AATD.Significant baseline differences suggested that PiSZ had presented earlier to health services than PiMM. Once this was accounted for, risk of emphysema did not differ between PiSZ and PiMM although survival was lower in PiMM patients (p<0.01).

CONCLUSIONS

PiSZ patients are less susceptible to cigarette smoke than PiZZ. The pattern of emphysema may be similar at diagnosis to usual COPD.

Clinical Informatics Fellowship Programs: In Search of a Viable Financial Model: An open letter to the Centers for Medicare and Medicaid Services

In the US, the new subspecialty of Clinical Informatics focuses on systems-level improvements in care delivery through the use of health information technology (HIT), data analytics, clinical decision support, data visualization and related tools. Clinical informatics is one of the first subspecialties in medicine open to physicians trained in any primary specialty. Clinical Informatics benefits patients and payers such as Medicare and Medicaid through its potential to reduce errors, increase safety, reduce costs, and improve care coordination and efficiency. Even though Clinical Informatics benefits patients and payers, because GME funding from the Centers for Medicare and Medicaid Services (CMS) has not grown at the same rate as training programs, the majority of the cost of training new Clinical Informaticians is currently paid by academic health science centers, which is unsustainable. To maintain the value of HIT investments by the government and health care organizations, we must train sufficient leaders in Clinical Informatics. In the best interest of patients, payers, and the US society, it is therefore critical to find viable financial models for Clinical Informatics fellowship programs. To support the development of adequate training programs in Clinical Informatics, we request that the Centers for Medicare and Medicaid Services (CMS) issue clarifying guidance that would allow accredited ACGME institutions to bill for clinical services delivered by fellows at the fellowship program site within their primary specialty.

Identification of novel vascular targets in lung cancer

BACKGROUND

Lung cancer remains the leading cause of cancer-related death, largely owing to the lack of effective treatments. A tumour vascular targeting strategy presents an attractive alternative; however, the molecular signature of the vasculature in lung cancer is poorly explored. This work aimed to identify novel tumour vascular targets in lung cancer.

METHODS

Enzymatic digestion of fresh tissue followed by endothelial capture with Ulex lectin-coated magnetic beads was used to isolate the endothelium from fresh tumour specimens of lung cancer patients. Endothelial isolates from the healthy and tumour lung tissue were subjected to whole human genome expression profiling using microarray technology.

RESULTS

Bioinformatics analysis identified tumour endothelial expression of angiogenic factors, matrix metalloproteases and cell-surface transmembrane proteins. Predicted novel tumour vascular targets were verified by RNA-seq, quantitative real-time PCR analysis and immunohistochemistry. Further detailed expression profiling of STEAP1 on 82 lung cancer patients confirmed STEAP1 as a novel target in the tumour vasculature. Functional analysis of STEAP1 using siRNA silencing implicates a role in endothelial cell migration and tube formation.

CONCLUSIONS

The identification of cell-surface tumour endothelial markers in lung is of interest in therapeutic antibody and vaccine development.

The Early Mobility Bundle: a simple enhancement of therapy which may reduce incidence of hospital-acquired pneumonia and length of hospital stay

BACKGROUND

Early mobility facilitated by physiotherapy has been shown to reduce the incidence of hospital-acquired pneumonia (HAP) in patients with hip fractures but its effect on HAP incidence in medical patients has not yet been studied.

AIM

To determine whether early mobility aided by physiotherapy reduces the incidence of HAP and length of stay in patients on medical wards.

METHODS

One respiratory and one elderly care medicine ward in one hospital association in Birmingham, UK, received the 'Early Mobility Bundle'. The bundle consisted of extra targeted physiotherapy and collaboration with ward staff to encourage and promote activity. The incidence of HAP, falls, pressure sores, length of stay (LOS) and activity level were then compared to two matched wards within the same hospital association.

RESULTS

HAP incidence was significantly lower in the intervention group (P < 0.0001) and remained so after adjusting for confounders (P = 0.001). Activity levels were higher (P = 0.04) and patients' LOS was more likely to fall in the lowest quartile (OR: 1.44; P = 0.009) in the intervention group. There was no significant difference in other outcomes.

CONCLUSION

The Early Mobility Bundle demonstrates a promising method to reduce the incidence of HAP and to increase activity in medical inpatients.

Solitons and thermal fluctuations in strongly nonlinear solids

We study a chain of anharmonic springs with tunable power law interactions as a minimal model to explore the propagation of strongly nonlinear solitary wave excitations in a background of thermal fluctuations. By treating the solitary waves as quasiparticles, we derive an effective Langevin equation and obtain their damping rate and thermal diffusion. These analytical findings compare favorably against numerical results from a Langevin dynamic simulation. In our chains composed of two-sided nonlinear springs, we report the existence of an expansion solitary wave (antisoliton) in addition to the compressive solitary waves observed for noncohesive macroscopic particles.

Genotype and clinical care correlations in craniosynostosis: findings from a cohort of 630 Australian and New Zealand patients

Craniosynostosis is one of the most common craniofacial disorders encountered in clinical genetics practice, with an overall incidence of 1 in 2,500. Between 30% and 70% of syndromic craniosynostoses are caused by mutations in hotspots in the fibroblast growth factor receptor (FGFR) genes or in the TWIST1 gene with the difference in detection rates likely to be related to different study populations within craniofacial centers. Here we present results from molecular testing of an Australia and New Zealand cohort of 630 individuals with a diagnosis of craniosynostosis. Data were obtained by Sanger sequencing of FGFR1, FGFR2, and FGFR3 hotspot exons and the TWIST1 gene, as well as copy number detection of TWIST1. Of the 630 probands, there were 231 who had one of 80 distinct mutations (36%). Among the 80 mutations, 17 novel sequence variants were detected in three of the four genes screened. In addition to the proband cohort there were 96 individuals who underwent predictive or prenatal testing as part of family studies. Dysmorphic features consistent with the known FGFR1-3/TWIST1-associated syndromes were predictive for mutation detection. We also show a statistically significant association between splice site mutations in FGFR2 and a clinical diagnosis of Pfeiffer syndrome, more severe clinical phenotypes associated with FGFR2 exon 10 versus exon 8 mutations, and more frequent surgical procedures in the presence of a pathogenic mutation. Targeting gene hot spot areas for mutation analysis is a useful strategy to maximize the success of molecular diagnosis for individuals with craniosynostosis.

Critical and umbilical points of a non-Gaussian random field

Random fields in nature often have, to a good approximation, Gaussian characteristics. For such fields, the number of maxima and minima are the same. Furthermore, the relative densities of umbilical points, topological defects which can be classified into three types, have certain fixed values. Phenomena described by nonlinear laws can, however, give rise to a non-Gaussian contribution, causing a deviation from these universal values. We consider a random surface, whose height is given by a nonlinear function of a Gaussian field. We find that, as a result of the non-Gaussianity, the density of maxima and minima no longer match and we calculate the relative imbalance between the two. We also calculate the change in the relative density of umbilics. This allows us not only to detect a perturbation, but to determine its size as well. This geometric approach offers an independent way of detecting non-Gaussianity, which even works in cases where the field itself can not be probed directly.

Extrema statistics in the dynamics of a non-Gaussian random field

When the equations that govern the dynamics of a random field are nonlinear, the field can develop with time non-Gaussian statistics even if its initial condition is Gaussian. Here, we provide a general framework for calculating the effect of the underlying nonlinear dynamics on the relative densities of maxima and minima of a two-dimensional field. Using this simple geometrical probe, we can identify the size of the non-Gaussian contributions in the random field, or alternatively the magnitude of the nonlinear terms in the underlying equations of motion. We demonstrate our approach by applying it to an initially Gaussian field that evolves according to the deterministic KPZ equation, which models surface growth and shock dynamics.

X-linked lymphoproliferative disease: prenatal detection of an unaffected histocompatible male

Chorionic Villous Biopsy (CVS) for diagnosis of XLP was undertaken at 10 weeks gestation in an obligate carrier. The fetus was found to be male by cytogenetic analysis. XLP (Xq25-q26) is closely linked to the RFLP markers DXS10, DXS37 and DXS42, but only DXS10 (distal to XLP) was informative for prenatal diagnosis in this family. RFLP analysis using this marker gave a 7% risk that the fetus was affected, based on the known recombination frequency between DXS10 and XLP. Further investigation was then undertaken to obtain a rapid and more accurate diagnosis using the three highly polymorphic PCR based markers. These were the AC repeat markers DXS424 (XL5A) and DXS425 (XL90A3) and the tetramer repeat marker within HPRT. DX425 is approximately 10 cM proximal to DXS10 and HPRT but is not known with certainty to map proximal or distal to XLP. DXS424 is proximal to DXS10 and HPRT and was inferred to be proximal to XLP on the basis of map distance from HPRT estimated by linkage analysis of data from CEPH pedigrees. This was confirmed by a recombinant in the XLP family between DXS424 and DXS425, placing DXS424 proximal to XLP. Diagnosis by linkage using DXS424 and DXS425, at least one of which is proximal to XLP, and distal markers DXS10 and HPRT, increased the accuracy of diagnosis using flanking marker analysis to greater than 99% that the fetus was unaffected. HLA DR typing of the CVS showed that the fetus was DR identical to a male sibling with XLP. HLA compatibility was confirmed at delivery by full HLA typing and MLC.(ABSTRACT TRUNCATED AT 250 WORDS)

SLUG (SNAI2) overexpression in embryonic development

The Snail-related zinc-finger transcription factor, SLUG (SNAI2), is critical for the normal development of neural crest-derived cells and loss-of-function SLUG mutations have been proven to cause piebaldism and Waardenburg syndrome type 2 in a dose-dependent fashion. However, little is known about the consequences of SLUG overexpression in embryonic development. We report SLUG duplication in a child with a unique de novo 8q11.2-->q13.3 duplication associated with tetralogy of Fallot, submucous cleft palate, renal anomalies, hypotonia and developmental delay. To investigate the effects of Slug overexpression on development, we analyzed mice carrying a Slug transgene. These mice were morphologically normal at birth, inferring that Slug overexpression is not sufficient to cause overt morphogenetic defects. In the adult mice, there was a 20% incidence of sudden death, cardiomegaly and cardiac failure associated with incipient mesenchymal tumorigenesis. These findings, while not directly implicating Slug in congenital and acquired heart disease, raise the possibility that Slug overexpression may contribute to specific cardiac phenotypes and cancer development.

Incontinentia pigmenti case series: clinical spectrum of incontinentia pigmenti in 53 female patients and their relatives

A retrospective case series of 53 female patients with incontinentia pigmenti (IP) including 28 secondary cases (female relatives of probands) was reviewed and compared with other series in an attempt to estimate more accurately the true disease burden of patients with IP. We found that, while the frequency of the first three cutaneous stages of IP was comparable with previous studies, none of the secondary cases manifested any serious neurological complications but all displayed stage IV pale anhidrotic reticulate lines on their posterior calves. This important clinical feature of IP in secondary cases has previously been under-represented in studies that often involved only paediatric probands. Hence, mildly affected cases of IP are often undiagnosed and under-represented in case series to date, possibly leading to inappropriately high estimates of neurological and eye involvement. With the availability of genetic testing, it is now feasible to confirm the variability of the phenotype and the risk of complications in IP.

Modified electrode placement must be recorded when performing 12-lead electrocardiograms

BACKGROUND

Local observation has suggested that placing limb leads on the torso when recording the standard 12-lead resting electrocardiogram (ECG) has become commonplace. This non-standard modification has the important advantages of ease and speed of application, and in an emergency may be applied with minimal undressing. Limb movement artefact is also reduced. It is believed that ECGs obtained with torso electrodes are interchangeable with standard ECGs and any minor electrocardiographic variations do not affect diagnostic interpretation.

STUDY DESIGN

The study compared 12-lead ECGs in 100 patients during routine electrocardiography, one being taken in the approved way and one taken with modified limb electrodes.

RESULTS

It was found that the use of torso leads produced important amplitude and waveform changes associated with a more vertical and rightward shift of the QRS frontal axis, particularly in those with abnormal standard ECGs. Such changes generated important ECG abnormalities in 36% of patients with normal standard ECGs, suggesting "heart disease of electrocardiographic origin". In those with abnormal standard ECGs, moving the limb leads to the torso made eight possible myocardial infarcts appear and five inferior infarcts disappeared. Twelve others developed clinically important T wave or QRS frontal axis changes.

CONCLUSIONS

It is vital that ECGs should be acquired in the standard way unless there are particular reasons for not doing so, and that any modification of electrode placement must be reported on the ECG itself. Marking the ECG "torso-positioned limb leads" or "non-standard" should alert the clinician to its limitations for clinical or investigative purposes, as any lead adaptation may modify the tracing and could result in misinterpretation.

De novo interstitial duplication 4(q28.1q35) associated with choanal atresia

We report a case of direct interstitial duplication of chromosome 4 from 4q28.1 to 4q35 associated with bilateral choanal atresia. The child also had dysmorphic features including a broad nasal bridge, telecanthus, downward slanting palpebral fissures, prominent ears, mild bilateral clinodactyly of the 5th fingers and bilateral hypoplasia of the 2nd-5th toenails. There was also a slightly dilated renal collecting system. At the age of 2.5 years, he had moderate global developmental delay, short, wide and tapering fingers, and short toes with hypoplastic toenails. To our knowledge, this is the second report of choanal atresia in a patient with trisomy 4q involving this region.

Emergency drug availability for the cardiac arrest team: a national audit

Cardiac arrest teams are called upon to deal with many different acute medical emergencies, including cardiac arrest. However, the drugs that are supplied for them to perform their role differs vastly from hospital to hospital. We have confirmed this in an audit of adult cardiac arrest teams from all the acute hospitals within Wales. The rational use of defibrillation and drugs during cardiopulmonary resuscitation has been standardised according to International guidelines, and there is no reason why resuscitation kits could not also be standardised. Further considerations of drug availability is needed for acute management of other collapsed patients without cardiac arrest, most commonly vaso-vagal syncope, anaphylaxis, hypoglycaemia, fits and respiratory arrest. Based upon recent recommendations from the project team of the Resuscitation Council (UK), augmented by other commonly needed drugs for first aid in the collapsed patient, we propose a reduced and simplified emergency drug list, employing a two box system covering immediate and most secondary requirements. A standardised format of drug kits for use by adult cardiac arrest teams could speed effective delivery of emergency care.

Attachment of astroglial cells to microfabricated pillar arrays of different geometries

We studied the attachment of astroglial cells on smooth silicon and arrays of silicon pillars and wells with various widths and separations. Standard semiconductor industry photolithographic techniques were used to fabricate pillar arrays and wells in single-crystal silicon. The resulting pillars varied in width from 0. 5 to 2.0 micrometer, had interpillar gaps of 1.0-5.0 micrometer, and were 1.0 micrometer in height. Arrays also contained 1.0-micromter-deep wells that were 0.5 micrometer in diameter and separated by 0.5-2.0 micrometer. Fluorescence, reflectance, and confocal light microscopies as well as scanning electron microscopy were used to quantify cell attachment, describe cell morphologies, and study the distribution of cytoskeletal proteins actin and vinculin on surfaces with pillars, wells, and smooth silicon. Seventy percent of LRM55 astroglial cells displayed a preference for pillars over smooth silicon, whereas only 40% preferred the wells to the smooth surfaces. Analysis of variance statistics performed on the data sets yielded values of p > approximately.5 for the comparison between pillar data sets and < approximately.0003 in the comparison between pillar and well data sets. Actin and vinculin distributions were highly polarized in cells found on pillar arrays. Scanning electron microscopy clearly demonstrated that cells made contact with the tops of the pillars and did not reach down into the spaces between pillars even when the interpillar gap was 5.0 microm. These experiments support the use of surface topography to direct the attachment, growth, and morphology of cells. These surfaces can be used to study fundamental cell properties such as cell attachment, proliferation, and gene expression. Such topography might also be used to modify implantable medical devices such as neural implants and lead to future developments in tissue engineering.

Manifestation of random phase in a finite ensemble of a turbulent fluid

A field can be specified by a set of spectral coefficients, c(j)(t), relative to an expansion basis. In fluid turbulence, one often assumes the condition that if one were to extract data from an ensemble of realizations, one would find that the average, <c(*)(i)(t)c(i('))(t)>, would vanish unless i = i('), as in the case of a homogeneous ensemble in which the i's represent wave vectors. We analytically treat an extension to the case in which one has a larger number of coefficients than realizations, introducing intrinsic linear dependences that vitiate the stated condition.

Personal illness models of diabetes: parents of preadolescents and adolescents

The purpose of this research was to explore personal illness models of parents of preadolescents and adolescents regarding diabetes mellitus. Personal illness models were defined as the parents' cognitive representations of the disease. Fifty-five parents of children ages 10 to 17 years with a diagnosis of insulin-dependent diabetes mellitus were interviewed using a semistructured questionnaire. Data were content analyzed for common themes. Parents attributed the cause of diabetes to genetics coupled with a viral infection. Most believed the diabetes would last a lifetime but they were hopeful for a cure. Parents requested ongoing education for their children, support groups, counseling, one consistent healthcare provider, and intensive insulin therapy. Parents reported that the major problems caused by diabetes were increased structure of daily routines and that their children with diabetes felt different from healthy peers. Parents' fears about diabetes included long-term complications, early death, and severe insulin reactions.

Personal illness models of diabetes: preadolescents and adolescents

The purpose of this research study was to explore personal illness models of preadolescents and adolescents regarding diabetes mellitus. Personal illness models were defined as the adolescents' cognitive representations of their disease. Sixty children ages 10 to 17 years with a diagnosis of insulin-dependent diabetes mellitus were interviewed using a semistructured questionnaire. Data were content analyzed for common themes. Although most participants expressed an understanding that their disease would last a lifetime, they were hopeful for a cure. Participants wanted healthcare professionals to provide strategies for controlling blood glucose to prevent future complications. Family and friends who followed the same diet as the adolescent with diabetes were viewed as supportive. The majority of adolescents were responsible for much of their own disease management. Their greatest fears concerned insulin reactions and long-term complications such as amputation of limbs.

FLT3 receptor expression on the surface of normal and malignant human hematopoietic cells

FLT3 ligand is a hematopoietic growth factor that plays a key role in growth of primitive hematopoietic cells. FLT3 receptor mRNA is found in early hematopoietic progenitors and in human myeloid leukemia blasts. Much less is known about the surface expression of FLT3 receptor on human hematopoietic cells. Using human 125I-FLT3 ligand, we have identified and characterized surface FLT3 receptors on normal and malignant human hematopoietic cells and cell lines. Our results showed that surface display of FLT3 receptor was greatest in fresh myeloid leukemia blast cells and myeloid leukemia cell lines. Erythroleukemic and megakaryocytic leukemia cell lines (n = 5) bound little to no 125I-FLT3 ligand. Scatchard analysis of 125I-FLT3 ligand binding data shows that three myeloid leukemia cell lines, ML-1, AML-193, and HL-60, as well as normal human marrow mononuclear cells, exhibit high affinity FLT3 receptors. Crosslinking of 125I-FLT3 ligand to FLT3 receptors on the surface of ML-1 myeloid leukemia cells indicates that the FLT3 ligand. The rates of FLT3 ligand internalization and degradation were determined by binding 125I-FLT3 ligand to ML-1 cells and acid stripping to distinguish surface bound from internalized ligand. Internalized 125I-FLT3 ligand was detected within 5 minutes after binding to ML-1 cells. In addition, we evaluated the effect of FLT3 ligand on megakaryocytic colony growth and nuclear endoreduplication, alone or in the presence of thrombopoietin. FLT3 ligand did not promote colony forming unit megakaryocyte (CFU-Meg) colony growth or megakaryocyte nuclear maturation, nor did FLT3 ligand augment the effects of thrombopoietin on these measures of megakaryopoiesis. These data indicate that the FLT3 receptor shares several characteristics with the c-kit receptor including dimerization and rapid internalization. However, the more restricted cellular distribution of the FLT3 receptor may target the effects of FLT3 ligand to primitive hematopoietic cells and to myeloid and lymphoid progenitor cells, in contrast to the pleiotropic effects of the c-kit receptor ligand, stem cell factor.

Long-term efficacy of subcutaneous sumatriptan using a novel self-injector

An open, multicenter study investigated the long-term efficacy, tolerability, and acceptability to patients of subcutaneous sumatriptan 6 mg, administered using a novel cartridge system self-injector, for the acute treatment of migraine. Eighty patients treated all migraine attacks for 6 months at home with a subcutaneous injection of sumatriptan 6 mg. A second injection could be taken after 1 to 24 hours if relief was inadequate, or if the headache recurred, and rescue medication could be taken 1 hour after the second injection. The primary end point was the percentage of attacks in which headache improved from severe or moderate before treatment to mild or absent at 1 hour after the first injection. A total of 1566 attacks were treated by the 80 patients and 69 patients completed 6 months of treatment. Headache relief was reported 1 hour after the first injection in a mean of 78% of attacks (83% in the first 3 months and 76% in the second 3 months). A second injection was required in a mean of 40% of attacks, and headache was mild or absent 1 hour after the second injection in a mean of 77% of attacks. Rescue medication was required after the second injection in a mean of 14% of attacks. At the end of the study, 87% of patients said that they would take the medication again, and at each clinic visit over 80% said that they found the injector easy to use. Adverse events were similar to those reported previously with sumatriptan and were mostly mild to moderate in intensity, short-lived, and resolved spontaneously. Subcutaneous sumatriptan 6 mg is an effective, well tolerated, and well accepted, long-term, acute treatment for migraine when self-injected by patients using the novel self-injector.

Effects of stem cell factor on the growth and radiation survival of tumor cells

Recombinant human stem cell factor (SCF) binds to the c-kit receptor on human bone marrow progenitor cells and enhances their survival following irradiation. Since the c-kit receptor has also been detected on malignant cells, experiments were performed to study the effect of SCF on the proliferation and radiation survival of a variety of both c-kit-positive and -negative human tumor cell lines using [3H]thymidine incorporation and colony formation assays. The addition of SCF to both c-kit-positive and -negative cell line cultures had no significant effect on the stimulation index (in [3H]thymidine assay). In contrast, colony formation by H69 (small cell lung cancer cell line), H128 (small cell lung cancer cell line), and HEL (erythroid leukemia cell line) cells was enhanced by SCF in a dose-dependent manner, but SCF did not promote the in vivo growth of H128 xenograft tumors in terms of graft rate, time from implantation to tumor detection, or tumor size. Furthermore, SCF did not significantly increase the surviving fraction of either c-kit-positive or -negative cell lines following radiation, and there were no statistically significant differences between D0 [defined by the slope of the terminal exponential region of the two-component (single-hit multitarget model) survival curve where slope = 1/D0], Dq (quasithreshold dose), n (extrapolation number), alpha, and beta values for any of the cell lines studied that were irradiated with and without SCF. Finally, nude mice with transplanted human LG425 cutaneous T-cell lymphoma (c-kit positive) were treated with 10 Gy with or without SCF (100 micrograms/kg i.p. 20 h before, 2 h before, and 4 h after irradiation). There were no significant differences in the median tumor quadrupling time between groups that received either no treatment or SCF alone, or between groups treated with 10 Gy and SCF or 10 Gy alone (P > 0.05). These results are encouraging and suggest that SCF does not stimulate tumor cell proliferation in vivo or enhance the survival of tumor cells following irradiation.

Identification and characterization of a soluble c-kit receptor produced by human hematopoietic cell lines

Stem cell factor (SCF) triggers cell growth by binding to cell surface c-kit receptors. Soluble forms of several cytokine receptors have been described and may play a role in the modulation of cytokine activity in vivo. For these reasons, we investigated whether human hematopoietic cells produce soluble c-kit receptors. The human leukemia cell lines OCIM1 and MO7e display approximately 80,000 and approximately 35,000 high-affinity cell surface c-kit receptors, respectively. Soluble c-kit receptors were detected by enzyme immunoassay in OCIM1 and MO7e culture supernatants. We determined the molecular weight and binding affinity of soluble c-kit receptor produced by OCIM1 cells, soluble c-kit receptor purified from human serum, and recombinant soluble c-kit receptor expressed in CHO cells. The three soluble c-kit receptors each have a molecular weight of 98 kD. Quantitative binding experiments with 125I-SCF indicate that the soluble c-kit receptors obtained from human serum or OCIM1 cells have binding affinities for SCF of approximately 200 to 300 pmol/L, in contrast to the recombinant form, which has a binding affinity of approximately 1.5 nmol/L. All three forms of the soluble c-kit receptor were able to compete with c-kit receptors on OCIM1 cells for 125I-SCF binding. Thus human hematopoietic cells can produce a soluble form of the c-kit receptor that retains high-affinity SCF binding activity. We speculate that the soluble c-kit receptor may bind SCF and function as a receptor antagonist in vivo.

Sumatriptan in acute migraine using a novel cartridge system self-injector. United Kingdom Study Group

This double-blind, randomized, placebo-controlled, parallel-group, multicenter study assessed the efficacy, acceptability, safety, and tolerability of subcutaneous sumatriptan 6 mg administered using a novel cartridge system self-injector for the acute treatment of migraine. Eighty-six patients treated one migraine attack at home with sumatriptan or placebo. A second identical injection was available after 1 hour for inadequate relief or if the headache recurred. Rescue medication was available 1 hour later. The primary end point was headache relief (improvement in headache from moderate or severe to mild or no pain) within 60 minutes of the first injection. Secondary end points included the acceptability of the self-injector, requirement for and efficacy of a second dose, relief of nonheadache symptoms, use of rescue medication, and adverse events. Significantly more patients taking sumatriptan than placebo reported headache relief 1 hour after the first injection (88% vs 11%, P < 0.001). The device was well accepted by patients; about 90% found it easy to use and wanted to take further medication using it. Significantly fewer patients taking sumatriptan than placebo required a second injection (33% vs 92%, P < 0.001) or rescue medication after the second injection (35% vs 67% P < 0.05). Significantly more patients taking sumatriptan than placebo reported headache relief after the second injection (83% vs 32%, P < 0.01), and resolution of nonheadache migraine symptoms (54% vs 23%, P < 0.01). Sumatriptan was generally well tolerated. Subcutaneous sumatriptan 6 mg self-administered using the novel self-injector is an effective, well accepted, and well tolerated acute treatment of migraine.

Counselling risk figures for fragile X carrier females of varying band sizes for use in predicting the likelihood of retardation in their offspring

We have derived risk figures for fra(X) syndrome carrier mothers based on their DNA status. Clinical and molecular information was analysed in 200 carrier mothers and their offspring. Individuals were classified as affected by a requirement for special education. Risk figures were calculated using the genotype of the intellectually normal offspring in order to reduce ascertainment bias. Analysis was made on women with differing mutation size to predict the proportion of affected offspring. Using this method the following risk figures were derived: 1. For carrier women with an increase (delta) of 0.06-0.14 Kb, the risk for having an affected son was 29% (1 in 3.5) and 25% for daughters (1 in 4). This predicts an overall 73% chance of a normal child. 2. For delta size 0.15-0.24 Kb, the risk of having an affected son was 46% (1 in 2.2) and 32% for daughters (1 in 3.1), predicting a 61% chance of a normal child. 3. For delta size > 0.24 Kb, normal transmitting male offspring were not seen, i.e., the risk for males was 50% (1 in 2) and for females 32% (1 in 3.1) which predicts a 59% chance of a normal child.

Cardiovascular status in young patients with insulin-dependent diabetes mellitus

BACKGROUND

Although the existence of diabetic cardiomyopathy in adults is firmly established, the presence of cardiac abnormalities in young diabetic patients is not universally accepted. We sought to determine the early stages of cardiac derangement and whether they are associated with renal dysfunction.

METHODS AND RESULTS

Thirty-nine patients (29 boys; mean age, 17.6 +/- 3.4 years) with insulin-dependent diabetes mellitus underwent echocardiography and timed overnight urine collection. Echocardiographic evaluation consisted of left ventricular mass, performance (shortening fraction, velocity of circumferential fiber shortening, stroke volume, and cardiac index), preload (end-diastolic dimension and volume), after-load (end-systolic wall stress and systemic vascular resistance), and contractility (velocity of fiber shortening relative to wall stress). Creatinine clearance and albumin excretion were measured from the urine sample. Glycosylated hemoglobin levels were measured; height and weight were measured; and Quetelet index (weight/height2) was calculated. These data were compared with control data. Left ventricular mass (26 +/- 6 versus 22 +/- 6 g/ht2.7, P < .01), the indexes of performance, blood pressure, and contractility (0.14 +/- 0.14 versus 0.003 +/- 0.03 circumference/s, P < .0003) were significantly higher in the diabetic patients than in control subjects. To evaluate the correlates of left ventricular mass and contractility in the diabetic patients, univariate and multiple regression analyses were performed. Significant univariate correlations of mass included albumin excretion (r = .36, P < .02), glycosylated hemoglobin (r = .35, P < .04), and stroke volume (r = .34, P < .03). A multivariate model included Quetelet index, albumin excretion, and duration of diabetes. Significant univariate correlations of contractility included insulin dosage (r = -.36, P < .02), creatinine clearance (r = .40, P < .02), and Quetelet index (r = .34, P < .03). A multivariate model included insulin dosage and creatinine clearance.

CONCLUSIONS

Early onset of diabetes mellitus is associated with increased left ventricular mass, performance, contractility, and blood pressure. These cardiovascular findings are correlated with increased creatinine clearance and microalbuminuria. These relations suggest that alterations in cardiovascular and renal function may occur in parallel in adolescents with insulin-dependent diabetes mellitus.

Adherence behaviors in research protocols: comparison of two interventions

The effectiveness of an enhanced preparation intervention was compared with the standard preparation intervention for accuracy in overnight urine specimen collections. The sample consisted of 179 individuals with type I insulin-dependent diabetes mellitus (IDDM). Subjects were assigned randomly to an enhanced or standard preparation group. The enhanced preparation included written instructions, a reminder to post instructions in the bathroom, a toilet seat cover with a reminder to save urine, and a nurse-initiated telephone call to review the instructions. The standard preparation included written instructions and a telephone number to call with any questions. For subjects without previous collection experience, significantly fewer inaccurate collections were reported in the enhanced preparation group than in the standard group (chi 2 = 4.61, P < .05). There were no differences in collection accuracy between enhanced and standard groups for subjects with collection experience (chi 2 = .4598, P > .05).

Nonhematopoietic tumor cell lines express stem cell factor and display c-kit receptors

Human stem cell factor (SCF) acts in the presence of other growth factors to stimulate the growth of primitive hematopoietic progenitor cells. These effects are performed by activation of the SCF receptor, c-kit. Because of the potential use of SCF in patients undergoing chemotherapy and bone marrow transplantation, the effect of SCF on nonhematopoietic tumors requires investigation. To determine whether human tumor cell lines display c-kit receptors, we performed binding experiments with 125I-SCF on a breast carcinoma cell line (Du4475), a gastric carcinoma cell line (KATO III), a melanoma cell line (HTT144), as well as two small cell lung carcinoma cell lines (H69 and H128). The biologic effect of SCF on tumor cell lines was assessed by its ability to stimulate tritiated thymidine uptake and to enhance colony growth in methylcellulose. The breast carcinoma cell line, Du4475, as well as two small cell lung carcinoma cell lines, H69 and H128, exhibit high-affinity c-kit receptors with approximate binding affinities of 40, 100, and 90 pmol/L, respectively. The number of high-affinity receptors per cell ranged from 700 to 9,500. The gastric carcinoma cell line, as well as the melanoma cell line, showed trace binding of 125I-SCF. In the presence of SCF alone, or in combination with granulocyte-macrophage colony-stimulating factor or interleukin-3, there was less than a 17% increase in the colony growth of Du4475, H69, or H128 cell lines. Postulating that the lack of growth response could be secondary to endogenous SCF production by the tumor cell lines, we used an RNAse protection assay to determine whether the tumor cell lines contain SCF messenger RNA (mRNA). In addition, we tested tumor cell line supernatants for the presence of secreted SCF protein by enzyme immunoassay, and analyzed the tumor cell lines for membrane-bound SCF by indirect immunofluorescence. Our results show that the Du4475, H69, and H128 cell lines, as well as a melanoma cell line (HTT144), have multiple copies of SCF mRNA. Soluble SCF protein was detected in the cell supernatants in the Du4475 and H69 cell lines and SCF was found on the surface of all four cell lines. These data show that some human solid tumor cell lines display high-affinity c-kit receptors and produce SCF, which can be detected on the cell surface. These results suggest the possibility that autocrine production of SCF by c-kit receptor-bearing tumor cells may enhance cell growth in tumor cell lines.

Profile of Renal Permselectivity by Simultaneous Enzyme-Linked Immunosorbent Assay of Albumin, Transferrin, IgG, and α1-Microglobulin with a New Microplate Reader

A competitive enzyme-linked immunosorbent assay (ELISA) is described for determining a renal permselectivity profile involving the urinary proteins albumin, transferrin, IgG, and alpha 1-microglobulin (alpha 1-m). The ELISA reader uses a computer-controlled array of multiplexed light-emitting diode (LED)-photodiode pairs for rapid measurements of absorbance on microplates. A 3,3'-dimethylnaphthidine reagent adapts the 3,5,3',5'-tetramethylbenzidine chromophore to monochromatic LED emission at 550 nm. We applied this ELISA to the determination of renal permselectivity in healthy children and young adults and in children with insulin-dependent diabetes mellitus. The geometric means (and SD) of protein excretion rates in a group of 85 normal subjects were as follows: albumin, 3.5 micrograms/min (1.83); transferrin, 173 ng/min (2.76); IgG, 1.11 micrograms/min (2.22), and alpha 1-m, 0.98 microgram/min (2.36).

Profile of renal permselectivity by simultaneous enzyme-linked immunosorbent assay of albumin, transferrin, IgG, and alpha 1-microglobulin with a new microplate reader

A competitive enzyme-linked immunosorbent assay (ELISA) is described for determining a renal permselectivity profile involving the urinary proteins albumin, transferrin, IgG, and alpha 1-microglobulin (alpha 1-m). The ELISA reader uses a computer-controlled array of multiplexed light-emitting diode (LED)-photodiode pairs for rapid measurements of absorbance on microplates. A 3,3'-dimethylnaphthidine reagent adapts the 3,5,3',5'-tetramethylbenzidine chromophore to monochromatic LED emission at 550 nm. We applied this ELISA to the determination of renal permselectivity in healthy children and young adults and in children with insulin-dependent diabetes mellitus. The geometric means (and SD) of protein excretion rates in a group of 85 normal subjects were as follows: albumin, 3.5 micrograms/min (1.83); transferrin, 173 ng/min (2.76); IgG, 1.11 micrograms/min (2.22), and alpha 1-m, 0.98 microgram/min (2.36).

Report on the X-linked lymphoproliferative disease in an Australian family

X-linked lymphoproliferative disease is characterized by immune deficiency, particularly to the Epstein-Barr virus and by a tendency to develop fatal infectious mononucleosis, acquired hypogammaglobulinaemia or malignant lymphoma. This disorder has been diagnosed in three boys, two brothers and a maternally related cousin, residing in Australia. The proband presented at 6 years of age with fulminating infectious mononucleosis. His 9 year old male cousin had developed an ileal Burkitt lymphoma one year earlier. Immunological and molecular genetic evidence is presented to support our view that his younger sibling is also affected with this condition. DNA linkage studies using probes to DXS10 and DXS37 provide confirmatory evidence for the diagnosis in the proband's brother and information on carrier status in female family members.