An Automated Brain Metastasis Detection and Segmentation System from MRI with a Large Multi-Institutional Dataset

PURPOSE/OBJECTIVE(S)

Developments of automated systems for brain metastasis (BM) detection and segmentation from MRI for assisting early detection and stereotactic radiosurgery (SRS) have been reported but most based upon relatively small datasets from single institutes. This work aims to develop and evaluate a system using a large multi-institutional dataset, and to improve both identification of small/subtle BMs and segmentation accuracy of large BMs.

MATERIALS/METHODS

A 3D U-Net system was trained and evaluated to detect and segment intraparenchymal BMs with a size > 2mm using 1856 MRI volumes from 1791 patients treated with SRS from seven institutions (1539 volumes for training, 183 for validation, and 134 for testing). All patients had 3D post-Gd T1w MRI scans pre-SRS. Gross tumor volumes (GTVs) of BMs for SRS were curated by each institute first. Then, additional efforts were spent to create GTVs for the untreated and/or uncontoured BMs, including central reviews by two radiologists, to improve accuracy of ground truth. The training dataset was augmented with synthetic BMs of 3773 MRIs using a 3D generative pipeline. Our system consists of two U-Nets with one using small 3D patches dedicated for detecting small BMs and another using large 3D patches for segmenting large BMs, and a random-forest based fusion module for combining the two network outputs. The first U-Net was trained with 3D patches containing at least one BM < 0.1 cm3. For detection performance, we measured BM-level sensitivity and case-level false-positive (FP) rate. For segmentation performance, we measured BM-level Dice similarity coefficient (DSC) and 95-percentile Hausdorff distance (HD95). We also stratified performances based upon BM sizes.

RESULTS

For 739 BMs in the 134 testing cases, the overall lesion-level sensitivity was 0.870 with an average case-level FP of 1.34±1.92 (95% CI: 1.02-1.67). The sensitivity was >0.969 for the BMs >0.1 cm3, but dropped to 0.755 for the BMs < 0.1 cm3 (Table 1). The average DSC and HD95 for all detected BMs were 0.786 and 1.35mm. The worse performance for BMs > 20 cm3 was caused by a case with 83 cm3 GTV and artifacts in the MRI volume.

CONCLUSION

We achieved excellent detection sensitivity and segmentation accuracy for BMs > 0.1 cm3, and promising performance for small BMs (<0.1cm3) with a controlled FP rate using a large multi-institutional dataset. Clinical utility for assisting early detection and SRS planning will be investigated. Table 1: Per-lesion detection and segmentation performance stratified by individual BM size. N is the number of BMs in each category.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Interactive 3D U-net for the segmentation of the pancreas in computed tomography scans

The increasing incidence of pancreatic cancer will make it the second deadliest cancer in 2030. Imaging based early diagnosis and image guided treatment are emerging potential solutions. Artificial intelligence (AI) can help provide and improve widespread diagnostic expertise and accurate interventional image interpretation. Accurate segmentation of the pancreas is essential to create annotated data sets to train AI, and for computer assisted interventional guidance. Automated deep learning segmentation performance in pancreas computed tomography (CT) imaging is low due to poor grey value contrast and complex anatomy. A good solution seemed a recent interactive deep learning segmentation framework for brain CT that helped strongly improve initial automated segmentation with minimal user input. This method yielded no satisfactory results for pancreas CT, possibly due to a sub-optimal neural network architecture. We hypothesize that a state-of-the-art U-net neural network architecture is better because it can produce a better initial segmentation and is likely to be extended to work in a similar interactive approach. We implemented the existing interactive method, iFCN, and developed an interactive version of U-net method we call iUnet. The iUnet is fully trained to produce the best possible initial segmentation. In interactive mode it is additionally trained on a partial set of layers on user generated scribbles. We compare initial segmentation performance of iFCN and iUnet on a 100CT dataset using dice similarity coefficient analysis. Secondly, we assessed the performance gain in interactive use with three observers on segmentation quality and time. Average automated baseline performance was 78% (iUnet) versus 72% (FCN). Manual and semi-automatic segmentation performance was: 87% in 15 min. for manual, and 86% in 8 min. for iUNet. We conclude that iUnet provides a better baseline than iFCN and can reach expert manual performance significantly faster than manual segmentation in case of pancreas CT. Our novel iUnet architecture is modality and organ agnostic and can be a potential novel solution for semi-automatic medical imaging segmentation in general.

Modified Immunodiffusion Method for Detection of Salmonella in Raw Flesh and Highly Contaminated Foods: Collaborative Study

A total of 19 government and private industry laboratories in Canada and the United States participated in the collaborative study. Naturally contaminated ground poultry and animal meals, as well as inoculated raw shrimp, were examined for presence of Salmonella by both the modified immunodiffusion method and the Bacteriological Analytical Manual culture method, resulting in an agreement rate of 93.1%. The 2 methods are statistically equivalent for all food types at each inoculation level and for all lots of naturally contaminated foods evaluated in this study. The modification of the AOAC Official Method 989.13, immunodiffusion (1–2 TEST) method for detection of motile Salmonella in all foods, has been adopted revised first action by AOAC INTERNATIONAL.

"It was the whole picture" a mixed methods study of successful components in an integrated wellness service in North East England

Background

A growing number of Local Authorities (LAs) have introduced integrated wellness services as part of efforts to deliver cost effective, preventive services that address the social determinants of health. This study examined which elements of an integrated wellness service in the north east of England were effective in improving health and wellbeing (HWB).

Methods

The study used a mixed-methods approach. In-depth semi-structured interviews (IVs) were conducted with integrated wellness service users (n = 25) and focus groups (FGs) with group based service users (n = 14) and non-service users (n = 23) to gather the views of stakeholders. Findings are presented here alongside analysis of routine monitoring data. The different data were compared to examine what each data source revealed about the effectiveness of the service.

Results

Findings suggest that integrated wellness services work by addressing the social determinants of health and respond to multiple complex health and social concerns rather than single issues. The paper identifies examples of ‘active ingredients’ at the heart of the programme, such as sustained relationships, peer support and confidence building, as well as the activities through which changes take place, such as sports and leisure opportunities which in turn encourage social interaction. Wider wellbeing outcomes, including reduced social isolation and increased self-efficacy are also reported.

Practical and motivational support helped build community capacity by encouraging community groups to access funding, helped navigate bureaucratic systems, and promoted understanding of marginalised communities. Fully integrated wellness services could support progression opportunities through volunteering and mentoring.

Conclusions

An integrated wellness service that offers a holistic approach was valued by service users and allowed them to address complex issues simultaneously. Few of the reported health gains were captured in routine data. Quantitative and qualitative data each offered a partial view of how effectively services were working.

'It is not a quick fix' structural and contextual issues that affect implementation of integrated health and well-being services: a qualitative study from North East England

OBJECTIVE

The objective of this article is to examine the factors affecting the design, commissioning and delivery of integrated health and well-being services (IHWSs), which seek to address multiple health-related behaviours, improve well-being and tackle health inequalities using holistic approaches.

STUDY DESIGN

Qualitative studies embedded within iterative process evaluations.

METHODS

Semi-structured interviews conducted with 16 key informants as part of two separate evaluations of IHWSs in North East England, supplemented by informal observations of service delivery. Transcripts and fieldnotes were analysed thematically.

RESULTS

The study findings identify a challenging organisational context in which to implement innovative service redesign, as a result of budget cuts and changes in NHS and local authority capacity. Pressures to demonstrate outcomes affected the ability to negotiate the practicalities of joint working. Progress is at risk of being undermined by pressures to disinvest before the long-term benefits to population health and well-being are realised. The findings raise important questions about contract management and relationships between commissioners and providers involved in implementing these new ways of working.

CONCLUSIONS

These findings provide useful learning in terms of the delivery and commissioning of similar IHWSs, contributing to understanding of the benefits and challenges of this model of working.

Beam distortion due to gold fiducial markers during salvage high-intensity focused ultrasound in the prostate

PURPOSE

High intensity focused ultrasound (HIFU) provides a non-invasive salvage treatment option for patients with recurrence after external beam radiation therapy (EBRT). As part of EBRT the prostate is frequently implanted with permanent fiducial markers. To date, the impact of these markers on subsequent HIFU treatment is unknown. The objective of this work was to systematically investigate, using computational simulations, how these fiducial markers affect the delivery of HIFU treatment.

METHODS

A series of simulations was performed modelling the propagation of ultrasound pressure waves in the prostate with a single spherical or cylindrical gold marker at different positions and orientations. For each marker configuration, a set of metrics (spatial-peak temporal-average intensity, focus shift, focal volume) was evaluated to quantify the distortion introduced at the focus. An analytical model was also developed describing the marker effect on the intensity at the focus. The model was used to examine the marker's impact in a clinical setting through case studies.

RESULTS

The simulations show that the presence of the marker in the pre-focal region causes reflections which induce a decrease in the focal intensity and focal volume, and a shift of the maximum pressure point away from the transducer's focus. These effects depend on the shape and orientation of the marker and become more pronounced as its distance from the transducer's focus decreases, with the distortion introduced by the marker greatly increasing when placed within 5 mm of the focus. The analytical model approximates the marker's effect and can be used as an alternative method to the computationally intensive and time consuming simulations for quickly estimating the intensity at the focus. A retrospective review of a small patient cohort selected for focal HIFU after failed EBRT indicates that the presence of the marker may affect HIFU treatment delivery.

CONCLUSIONS

The distortion introduced by the marker to the HIFU beam when positioned close to the focus may result in an undertreated region beyond the marker due to less energy arriving at the focus, and an overtreated region due to reflections. Further work is necessary to investigate whether the results presented here justify the revision of the patient selection criteria or the markers' placement protocol.

3D prostate histology reconstruction: an evaluation of image-based and fiducial-based algorithms

PURPOSE

Evaluation of in vivo prostate imaging modalities for determining the spatial distribution and aggressiveness of prostate cancer ideally requires accurate registration of images to an accepted reference standard, such as histopathological examination of radical prostatectomy specimens. Three-dimensional (3D) reconstruction of prostate histology facilitates these registration-based evaluations by reintroducing 3D spatial information lost during histology processing. Because the reconstruction accuracy may constrain the clinical questions that can be answered with these data, it is important to assess the tradeoffs between minimally disruptive methods based on intrinsic image information and potentially more robust methods based on extrinsic fiducial markers.

METHODS

Ex vivo magnetic resonance (MR) images and digitized whole-mount histology images from 12 radical prostatectomy specimens were used to evaluate four 3D histology reconstruction algorithms. 3D reconstructions were computed by registering each histology image to the corresponding ex vivo MR image using one of two similarity metrics (mutual information or fiducial registration error) and one of two search domains (affine transformations or a constrained subset thereof). The algorithms were evaluated for accuracy using the mean target registration error (TRE) computed from homologous intrinsic point landmarks (3-16 per histology section; 232 total) identified on histology and MR images, and for the sensitivity of TRE to rotational, translational, and scaling initialization errors.

RESULTS

The algorithms using fiducial registration error and mutual information had mean ± standard deviation TREs of 0.7 ± 0.4 and 1.2 ± 0.7 mm, respectively, and one algorithm using fiducial registration error and affine transforms had negligible sensitivities to initialization errors. The postoptimization values of the mutual information-based metric showed evidence of errors due to both the optimizer and the similarity metric, and variation of parameters of the mutual information-based metric did not improve its performance.

CONCLUSIONS

The extrinsic fiducial-based algorithm had lower mean TRE and lower sensitivity to initialization than the intrinsic intensity-based algorithm using mutual information. A model relating statistical power to registration error for certain imaging validation study designs estimated that a reconstruction algorithm with a mean TRE of 0.7 mm would require 27% fewer subjects than the method used to initialize the algorithms (mean TRE 1.3 ± 0.7 mm), suggesting the choice of reconstruction technique can have a substantial impact on the design of imaging validation studies, and on their overall cost.

Synthesis and properties of a meso- tris–ferrocene appended zinc(ii) porphyrin and a critical evaluation of its dye sensitised solar cell (DSSC) performance

A zinc(ii) porphyrin derivative, F3P, was prepared containing a single ferrocene group appended at three of the meso positions.

Peri-procedural bridging with low molecular weight heparin in patients receiving warfarin for venous thromboembolism: a pediatric experience

INTRODUCTION

The incidence of venous thromboembolism (VTE) in children appears to be increasing, and warfarin remains one of the few standard anticoagulants used for secondary VTE prevention. When invasive procedures are required in adults with high TE risk who are receiving warfarin, low-molecular weight heparin (LMWH) bridging is recommended, based mainly upon observational evidence; in children, no such studies have been published. We sought to determine the risks of recurrent TE (both VTE and arterial TE [ATE]) and major bleeding with peri-procedural LMWH bridging in children receiving warfarin for VTE.

METHODS

Children (age≤21years of age at the time of bridge) receiving warfarin for VTE and undergoing a standardized clinical care protocol for peri-procedural LMWH bridging were enrolled and followed in an institution-based prospective inception cohort study at Children's Hospital Colorado between March 2006 and February 2012. Outcomes were assessed at 30days post-procedure, and followed International Society on Thrombosis and Haemostasis guidelines.

RESULTS

Seventeen children comprised the cohort, with a total of 23 bridging episodes. Median age at bridging episode was 17.5years (range, 12 to 21years). In 22% of bridging episodes, indication was for major surgery. Median duration of LMWH administration prior to procedure was 6days (range, 4-10days); median duration off anticoagulation peri-procedurally was 1.5days (range: 1-2days). The risks of major bleeding, recurrent VTE, and ATE at 30days post-procedure were 4.3% (1/23), 0% and 0%, respectively.

CONCLUSIONS

This study provides important preliminary data on safety and efficacy of perioperative LMWH bridging for adolescent VTE patients receiving warfarin. Larger collaborative pediatric studies are warranted to substantiate these findings and to investigate prognostic factors of bleeding and recurrent TE in this setting.

Lesion Explorer: a comprehensive segmentation and parcellation package to obtain regional volumetrics for subcortical hyperintensities and intracranial tissue

Subcortical hyperintensities (SH) are a commonly observed phenomenon on MRI of the aging brain (Kertesz et al., 1988). Conflicting behavioral, cognitive and pathological associations reported in the literature underline the need to develop an intracranial volumetric analysis technique to elucidate pathophysiological origins of SH in Alzheimer's disease (AD), vascular cognitive impairment (VCI) and normal aging (De Leeuw et al., 2001; Mayer and Kier, 1991; Pantoni and Garcia, 1997; Sachdev et al., 2008). The challenge is to develop processing tools that effectively and reliably quantify subcortical small vessel disease in the context of brain tissue compartments. Segmentation and brain region parcellation should account for SH subtypes which are often classified as: periventricular (pvSH) and deep white (dwSH), incidental white matter disease or lacunar infarcts and Virchow-Robin spaces. Lesion Explorer (LE) was developed as the final component of a comprehensive volumetric segmentation and parcellation image processing stream built upon previously published methods (Dade et al., 2004; Kovacevic et al., 2002). Inter-rater and inter-method reliability was accomplished both globally and regionally. Volumetric analysis showed high inter-rater reliability both globally (ICC=.99) and regionally (ICC=.98). Pixel-wise spatial congruence was also high (SI=.97). Whole brain pvSH volumes yielded high inter-rater reliability (ICC=.99). Volumetric analysis against an alternative kNN segmentation revealed high inter-method reliability (ICC=.97). Comparison with visual rating scales showed high significant correlations (ARWMC: r=.86; CHIPS: r=.87). The pipeline yields a comprehensive and reliable individualized volumetric profile for subcortical vasculopathy that includes regionalized (26 brain regions) measures for: GM, WM, sCSF, vCSF, lacunar and non-lacunar pvSH and dwSH.

Access to medical records for research purposes: varying perceptions across research ethics boards

INTRODUCTION

Variation across research ethics boards (REBs) in conditions placed on access to medical records for research purposes raises concerns around negative impacts on research quality and on human subject protection, including privacy.

AIM

To study variation in REB consent requirements for retrospective chart review and who may have access to the medical record for data abstraction.

METHODS

Thirty 90-min face-to-face interviews were conducted with REB chairs and administrators affiliated with faculties of medicine in Canadian universities, using structured questions around a case study with open-ended responses. Interviews were recorded, transcribed and coded manually.

RESULTS

Fourteen sites (47%) required individual patient consent for the study to proceed as proposed. Three (10%) indicated that their response would depend on how potentially identifying variables would be managed. Eleven sites (38%) did not require consent. Two (7%) suggested a notification and opt-out process. Most stated that consent would be required if identifiable information was being abstracted from the record. Among those not requiring consent, there was substantial variation in recognising that the abstracted information could potentially indirectly re-identify individuals. Concern over access to medical records by an outside individual was also associated with requirement for consent. Eighteen sites (60%) required full committee review. Sixteen (53%) allowed an external research assistant to abstract information from the health record.

CONCLUSIONS

Large variation was found across sites in the requirement for consent for research involving access to medical records. REBs need training in best practices for protecting privacy and confidentiality in health research. A forum for REB chairs to confidentially share concerns and decisions about specific studies could also reduce variation in decisions.

Determination of the pion charge form factor at Q2=1.60 and 2.45 (GeV/c)2

The 1H(e,e'pi+)n cross section was measured at four-momentum transfers of Q2=1.60 and 2.45 GeV2 at an invariant mass of the photon nucleon system of W=2.22 GeV. The charged pion form factor (F(pi)) was extracted from the data by comparing the separated longitudinal pion electroproduction cross section to a Regge model prediction in which F(pi) is a free parameter. The results indicate that the pion form factor deviates from the charge-radius constrained monopole form at these values of Q2 by one sigma, but is still far from its perturbative quantum chromodynamics prediction.

Meeting maximum residue limits: an improved screening technique for the rapid detection of antimicrobial residues in animal food products

A rapid, high-throughput antimicrobial screening assay was developed using either a physical fluid extraction or a solvent extraction technique coupled to the commercially available PremiTest. The solvent extraction approach was fully validated for a wide range of tissues and the fluid extraction approach partially validated for porcine muscle. Both procedures can detect a wide range of antimicrobial compounds at or below maximum residue limit concentrations. The use of a solvent extraction provides an enhanced test capable of detecting a wider range of drugs than the fluid extraction approach at or below half maximum residue limit levels in a variety of matrices. Biochemical methods for the class-specific identification of beta-lactams and sulphonamides following initial screening were developed and validated. The approach is a significant improvement on existing methodologies as a tool for residues monitoring in surveillance programmes.

Recency in verb phrase attachment

Four experiments investigated attachment preferences in constructions involving 3 verb phrases (VPs) followed by an attaching modifier. Readers preferred attachment to the most recent (lowest) VP site overall and preferred to attach the modifier to the middle VP over the highest VP, demonstrating a monotonic recency-based preference ordering. This pattern could not be attributed to lexical or plausibility-based preferences. The results contrast with the pattern for relative clause attachment into 3 potential noun phrase sites, where the preference ordering is nonmonotonic (e.g., E. Gibson, N. J. Pearlmutter, E. Canseco-Gonzalez, & G. Hickok, 1996), and support the multiple-constraint theory described by E. Gibson and N. J. Pearlmutter (1998), which proposes that recency/locality and a secondary factor, predicate proximity, combine with lexical, grammatical, prosodic, and contextual constraints to determine attachment preferences.

Determination of synovial fluid and serum concentrations, and morphologic effects of intraarticular ceftiofur sodium in horses

OBJECTIVES

To determine the serum and synovial fluid concentrations of ceftiofur sodium after intraarticular (IA) and intravenous (IV) administration and to evaluate the morphologic changes after intraarticular ceftiofur sodium administration.

STUDY DESIGN

Strip plot design for the ceftiofur sodium serum and synovial fluid concentrations and a split plot design for the cytologic and histopathologic evaluation.

ANIMALS

Six healthy adult horses without lameness.

METHODS

Stage 1: Ceftiofur sodium (2.2 mg/kg) was administered IV. Stage 2: 150 mg (3 mL) of ceftiofur sodium (pHavg 6.57) was administered IA into 1 antebrachiocarpal joint. The ceftiofur sodium was reconstituted with sterile sodium chloride solution (pH 6.35). The contralateral joint was injected with 3 mL of 0.9% sterile sodium chloride solution (pH 6.35). Serum and synovial fluid samples were obtained from each horse during each stage. For a given stage, each type of sample (serum or synovial fluid) was collected once before injection and 12 times after injection over a 24-hour period. All horses were killed at 24 hours, and microscopic evaluation of the cartilage and synovium was performed. Serum and synovial fluid concentrations of ceftiofur sodium were measured by using a microbiologic assay, and pharmacokinetic variables were calculated. Synovial fluid was collected from the active joints treated during stage 2 at preinjection and postinjection hours (PIH) 0 (taken immediately after injection of either the ceftiofur sodium or sodium chloride), 12, and 24, and evaluated for differential cellular counts, pH, total protein concentration, and mucin precipitate quality.

RESULTS

Concentrations of ceftiofur in synovial fluid after IA administration were significantly higher (P = .0001) than synovial fluid concentrations obtained after IV administration. Mean peak synovial fluid concentrations of ceftiofur after IA and IV administration were 5825.08 microg/mL at PIH .25 and 7.31 microg/mL at PIH 4, respectively. Mean synovial fluid ceftiofur concentrations at PIH 24 after IA and IV administration were 4.94 microg/mL and .12 microg/mL, respectively. Cytologic characteristics of synovial fluid after IA administration did not differ from cytologic characteristics after IA saline solution administration. White blood cell counts after IA ceftiofur administration were < or =3,400 cells/ML. The mean synovial pH of ceftiofur treated and control joints was 7.32 (range, 7.08-7.5) and 7.37 (range, 7.31-7.42), respectively. Grossly, there were minimal changes in synovium or cartilage, and no microscopic differences were detected (P = .5147) between ceftiofur-treated joints and saline-treated joints. The synovial half-life of ceftiofur sodium after IA administration joint was 5.1 hours.

CONCLUSIONS

Synovial concentrations after intraarticular administration of 150 mg of ceftiofur sodium remained elevated above minimal inhibitory concentration (MIC90) over 24 hours. After 2.2 mg/kg IV, the synovial fluid ceftiofur concentration remained above MIC no longer than 8 hours.

CLINICAL RELEVANCE

Ceftiofur sodium may be an acceptable broad spectrum antimicrobial to administer IA in septic arthritic equine joints.

Effect of nonviable infants on the infant mortality rate in Philadelphia, 1992

OBJECTIVES

This report measured the effect of births at 22 weeks' gestation or earlier on infant mortality in Philadelphia, Pa.

METHODS

The proportion of live-born deliveries at 22 weeks or earlier was calculated. Overall and race-specific infant mortality was calculated after excluding live-born deliveries at 22 weeks' gestation or earlier.

RESULTS

Of all deliveries, 1.5% were at 22 weeks or earlier. Of these, 68% were stillborn and 32% were live-born. Large hospital-to-hospital variation in the proportion of live-born deliveries at 22 weeks' gestation or earlier was noted. When nonviable births were excluded, overall infant mortality decreased 40%.

CONCLUSIONS

The development of a standardized birth certificate policy is needed and will facilitate comparisons of infant mortality across spatial boundaries and racial/ethnic groups.

Infant sleep position practices 2 years into the "back to sleep" campaign

Since the 1992 American Academy of Pediatrics (AAP) recommendation to put babies to sleep in the nonprone position and the subsequent 1994 "Back to Sleep" campaign, the U.S. rate of sudden infant death syndrome (SIDS) has decreased more than 40%. This study reports sleep position practices in the greater Philadelphia area during 1996 and 1997. Four hundred and ten parents of infants 6 months of age or less answered a questionnaire by interview in Philadelphia clinics and private pediatric offices from December 1995 through February 1997. Sleep position practices and other SIDS risk factors were measured among demographic groups and compared with reported rates in a similar population from 1993 and 1994. Data were analyzed by Chi square after analysis of correlation coefficients. Significance is reported at p < 0.05. Seventy-two percent of all infants surveyed slept nonprone (NP) compared to 31.8% in 1993 and 59.1% in 1994. The population was 61% African-American (AA), 62% clinic patients. The breast feeding rate was 31%, maternal smoking 17%, and cosleeping 46%. AA infants (67% vs. 82%), infants receiving care at a clinic (66% vs. 84%), and infants > 3 months old (65% vs. 76%) are less likely to be placed nonprone. Most parents who place infants on their back report it was recommended by a medical professional (56%). The majority of those placing infants prone do so because their infant is more comfortable or sleeps better (65%), although 73% said their physician/nurse discussed sleep position with them. Nonprone sleeping continues to increase since the initiation of the "Back to Sleep" campaign. Disparity between some demographic groups persists. An excessive number of African-American families and clinic families still choose a prone sleep position. Many who do so cite increased infant comfort, despite knowledge of the AAP recommendation.

Distinguishing serial and parallel parsing

This paper discusses ways of determining whether the human parser is serial maintaining at most, one structural interpretation at each parse state, or whether it is parallel, maintaining more than one structural interpretation in at least some circumstances. We make four points. The first two counterclaims made by Lewis (2000): (1) that the availability of alternative structures should not vary as a function of the disambiguating material in some ranked parallel models; and (2) that parallel models predict a slow down during the ambiguous region for more syntactically ambiguous structures. Our other points concern potential methods for seeking experimental evidence relevant to the serial/parallel question. We discuss effects of the plausibility of a secondary structure in the ambiguous region (Pearlmutter & Mendelsohn, 1999) and suggest examining the distribution of reaction times in the disambiguating region.

Recency and lexical preferences in Spanish

One experiment provided evidence in support of Gibson, Pearlmutter, Canseco-Gonzalez, and Hickok's (1996) claim that a recency preference applies to Spanish relative clause attachments, contrary to the claim made by Cuetos and Mitchell (1988). Spanish speakers read stimuli involving either two or three potential attachment sites in which the same lexical content of the two-site conditions appeared in a different structural configuration in the three-site conditions. High attachment was easier than low attachment when only two sites were present, but low attachment was preferred over high attachment, which was in turn preferred over middle attachment, when three sites were present. The experiment replicated earlier results and showed that (1) attachment preferences are determined in part by a preference to attach recently/low, and (2) lexical biases are insufficient to explain attachment preferences.

Assessment of infant cardiopulmonary resuscitation rescue breathing technique: relationship of infant and caregiver facial measurements

OBJECTIVE

Although a few infants ever require resuscitation, pediatric cardiopulmonary resuscitation (CPR) is performed most commonly under 1 year of age. American Heart Association guidelines for pediatric basic life support recommend that the caregiver place his/her mouth over the infant's mouth and nose to create a seal. The way CPR is currently taught encourages parents to attempt to seal the nose and open the mouth of the infant for rescue breathing. Recent studies suggest some parents may have trouble sealing an infant's nose and open mouth, but their study participant numbers were small. The aim of this report is to estimate, among a large cohort, the ability of caregivers to create a seal to their infants for the provision of rescue breathing according to current guidelines.

METHODS

Infants up to 1 year of age (n = 281) and their caregivers were enrolled from Philadelphia pediatric offices. Facial measurements of the infants were obtained to estimate the length needed to seal the nose and open mouth, and the nose and closed mouth. Mouth widths of the caregivers were compared with their infant's nose and mouth lengths. One-way analysis of variance with Tukey's postmortem analysis and ordinary least squares means regression were used for univariate analysis with analysis of covariance used to control for the effects of multiple variables when necessary. Infant measurements were stratified into 3-month age quadrants to compare against matched adult caregiver measurements.

RESULTS

Most caregivers (n = 270) were female. Females had smaller mouth widths than males (4.9 +/- 0.5 cm vs 5.2 +/- 0.5 cm). Infant nose and mouth length increased during the first year of life, with the largest increase between 0 to 3 months and 3 to 6 months (4.2 +/- 0.4 cm to 4.7 +/- 0.4 cm). As infant age and face length increased, a progressively higher rate of adult females were estimated not to be able to cover their infant's nose and open mouth, with the greatest increase again between 0 to 3 months (9%) and 3 to 6 months (40%). All female caregivers except 1 were predicted to be able to seal their infant's nose and closed mouth by our measurements.

CONCLUSIONS

Infant face length grows rapidly during the first year of life with the most rapid growth occurring during the first 6 months. As early as 3 to 6 months of infant age, many adult caregivers' facial measurements, especially female, predict that they may not be able to form a seal for mouth-to-nose and open-mouth infant rescue breathing. By related measurements, nearly 100% of caregivers should be able to seal their infant's nose and closed mouth. If facial measurement predictions correlate with functional inability to seal an infant's nose and open mouth, infant CPR rescue breathing instruction will need to emphasize head position and creation of a seal over the mouth and nose without teaching that the mouth be open. pediatric basic life support, infant CPR, rescue breathing, sudden infant death syndrome, acute life-threatening episode.

Processing syntactic relations in language and music: an event-related potential study

In order to test the language-specificity of a known neural correlate of syntactic processing [the P600 event-related brain potential (ERP) component], this study directly compared ERPs elicited by syntactic incongruities in language and music. Using principles of phrase structure for language and principles of harmony and key-relatedness for music, sequences were constructed in which an element was either congruous, moderately incongruous, or highly incongruous with the preceding structural context. A within-subjects design using 15 musically educated adults revealed that linguistic and musical structural incongruities elicited positivities that were statistically indistinguishable in a specified latency range. In contrast, a music-specific ERP component was observed that showed antero-temporal right-hemisphere lateralization. The results argue against the language-specificity of the P600 and suggest that language and music can be studied in parallel to address questions of neural specificity in cognitive processing.

Linguistic complexity: locality of syntactic dependencies

This paper proposes a new theory of the relationship between the sentence processing mechanism and the available computational resources. This theory--the Syntactic Prediction Locality Theory (SPLT)--has two components: an integration cost component and a component for the memory cost associated with keeping track of obligatory syntactic requirements. Memory cost is hypothesized to be quantified in terms of the number of syntactic categories that are necessary to complete the current input string as a grammatical sentence. Furthermore, in accordance with results from the working memory literature both memory cost and integration cost are hypothesized to be heavily influenced by locality (1) the longer a predicted category must be kept in memory before the prediction is satisfied, the greater is the cost for maintaining that prediction; and (2) the greater the distance between an incoming word and the most local head or dependent to which it attaches, the greater the integration cost. The SPLT is shown to explain a wide range of processing complexity phenomena not previously accounted for under a single theory, including (1) the lower complexity of subject-extracted relative clauses compared to object-extracted relative clauses, (2) numerous processing overload effects across languages, including the unacceptability of multiply center-embedded structures, (3) the lower complexity of cross-serial dependencies relative to center-embedded dependencies, (4) heaviness effects, such that sentences are easier to understand when larger phrases are placed later and (5) numerous ambiguity effects, such as those which have been argued to be evidence for the Active Filler Hypothesis.

Earlier discharge of infants from neonatal intensive care units: a pilot program of specialized case management and home care. Delaware Valley Child Health Alliance

A multidisciplinary approach using a neonatology independent physicians association, affiliated hospitals, a pediatric home care company, and a health maintenance organization was designed to promote earlier safe discharge of infants from intensive care. This pilot project involved 43 infants who received case management and early discharge home with home oxygen, monitoring, intravenous antibiotics, gavage feedings, phototherapy, or nutritional management for poor weight gain. A staff neonatologist remained the primary physician until the patient would have been discharged according to standard criteria. Two patients had unscheduled readmissions and all infants survived. This approach resulted in an estimated savings of 456 hospital days and $329,982; 89% of parents rated the care as good to excellent, and 83% were satisfied with the program and outcome. This study suggests that a prospectively designed program can be designed to promote safe earlier discharge of infants in intensive care.

Sudden infant death syndrome rates subsequent to the American Academy of Pediatrics supine sleep position

OBJECTIVES

In April 1992, the American Academy of Pediatrics (AAP) recommended that healthy infants be positioned for sleep on their side or back to reduce the risk of Sudden Infant Death Syndrome (SIDS). The authors hypothesized three different forms of the intervention to examine the impact of the recommendation according to theory such as technology diffusion. Seasonality was included in the models to control its effect when testing.

METHODS

Box and Tiao time-series intervention methodology was used to examine the effect of the AAP recommendation on SIDS rates. Sudden Infant Death Syndrome mortality data from Philadelphia and Chicago were examined separately for white and nonwhite populations over 32 quarters.

RESULTS

Overall SIDS rates dropped significantly according to an abrupt effect from the intervention. However, the effect appeared to be gradually declining in Philadelphia but permanent in Chicago. In Philadelphia, a decline of 62.3% was estimated in whites in the first quarter after the intervention but decreased to only 5% in the last quarter of 1994. A decline of 35.8% was estimated in nonwhites in the first quarter after the intervention but decreased to only 9.4% in the last quarter of 1994. An abrupt and permanent decrease of 26.7% and 16.5% was found in Chicago for whites and nonwhites, respectively.

CONCLUSIONS

Evidence of an abrupt adoption of the recommendation can be explained by the authority innovation decision made by the AAP. Some evidence was found that the effect is temporary, perhaps because physicians are reversing earlier decisions. The demonstrated methodology provides a powerful way to test naturally occurring interventions from quasiexperimental designs to test the impact of policy guidelines.

Skin-to-skin parental contact with fragile preterm infants

Skin-to-skin contact has been implemented recently to facilitate maternal-infant bonding of preterm infants. The technique allows the removal of fragile preterm infants from an incubator to the bare chest of a parent or caretaker. When specific guidelines are followed, thermal stability can be maintained, parent-infant bonding can be facilitated, and parental satisfaction can be enhanced. We illustrate a case in which a preterm infant has skin-to-skin contact while being monitored for physiologic parameters, including heart and respiratory rate, oxyhemoglobin saturation, and nasal airflow. Improvements in breathing patterns in this infant during skin-to-skin care and maintenance of a normal temperature suggest that this technique may not only be safe and psychologically beneficial, but it may also promote physiologic improvement.

Documented home apnea monitoring: effect on compliance, duration of monitoring, and validation of alarm reporting

The objectives of this study were to: (1) measure patient compliance with monitoring, (2) validate parental reports of alarms at home, (3) examine monitoring duration, and (4) compare documented monitor records with the traditional pneumogram to evaluate patients for monitor discontinuation. During the 1-year period from January through December, 1992, 114 infants were followed up with documented monitoring. Simultaneously, 113 infants were followed up with conventional monitors. Infants were premature, or victims of apparent life-threatening episodes (ALTE), or siblings of SIDS victims. Monitors recorded all episodes of apnea greater than 15 seconds and bradycardia less than 80 beats per minute. All families were contacted biweekly by telephone. Downloads were performed at regular intervals. Monitor downloads were compared with simultaneous pneumograms to assess the accuracy of a long-term, intermittent event-recording system versus short-term (6- to 12-hour) continuous recording. All families were highly compliant with the use of home monitoring. Although Caucasian families used the monitors more often than non-Caucasian families, all groups used the monitor > 75% of the time. True episodes were verified in 38% of patients by monitor downloads. Only 7.4% of all recorded events were true events. Of the real events, 51.2% were apneas of 16-20 seconds. No significant differences were found in overall duration of monitoring between documented and nondocumented monitors. In the premature infants, the duration of monitoring was significantly reduced in those infants found to have no true episodes over those with real events at home. Readmission for ALTE was reduced in infants with documented monitors. Premature infants without events were monitored an average of 24 fewer days (P = 0.03). Computerized monitor downloads were found to be equally, if not more, sensitive than pneumograms in evaluating infants for monitor discontinuation. Documented monitoring offers a viable alternative to traditional monitoring and pneumograms in assisting clinicians and families in evaluating their infant's progress. By accurately assessing compliance, distinguishing true from false alarms, and decreasing the need for pneumograms, these devices provide valuable information to clinicians and families.

Effects of sweet taste stimulation on growth and sucking in preterm infants

OBJECTIVE

To evaluate the effect of sweet taste stimulation in augmenting the reported growth-enhancing effects of nonnutritive sucking in preterm infants who are gavage-fed.

DESIGN

Random assignment of preterm infants to receive stimulation by one of three methods during each feeding until totally orally fed.

SETTING

Hospital intensive-care and infant transitional units.

PATIENTS

Eligibility criteria included body weight greater than or equal to 1,250 g, gestational age younger than 34 weeks, growth parameters appropriate for gestational age, tolerating at least 100 kcals/kg/day by gavage feeding with evidence of weight gain, and no clinical evidence of health complications. Data are presented for 42 infants who completed 14 days of treatment.

INTERVENTIONS

Exposure to a sweet pacifier, a latex pacifier, or maternal heartbeat sounds during gavage feedings.

MAIN OUTCOME MEASURES

Growth, time to total oral feeding, and sucking responses.

RESULTS

No significant differences in sucking measures were noted among treatment groups. Differences in progression time to total oral feedings and weight gain favored the sweet-pacifier group but were not statistically significant.

CONCLUSIONS

Oral stimulation of gavage-fed, preterm infants during a 2-week hospitalization was not sufficient to elicit a significant improvement in growth efficiency, progression to total oral feedings, or sucking maturation. Additional studies may show a beneficial effect of chemosensory stimulation in preterm infants.

Recency preference in the human sentence processing mechanism

Cuetos and Mitchell (1988) observed that in constructions in which a relative clause can attach to one of two possible sites, English speakers prefer the more recent attachment site, but Spanish speakers prefer the least recent attachment site, in violation of the proposed universal principle Late Closure (Recency Preference), which favors attachments to the most recent sites. Based on this evidence, Cuetos and Mitchell concluded that Late Closure is not a universal principle of the human sentence processing mechanism. In this paper, we provide new evidence from Spanish and English self-paced reading experiments on relative clause attachment ambiguities that involve three possible attachment sites. The results of our experiments suggest that a principle like Late Closure is in fact universally operative in the human parser, but that it is modulated by at least one other factor in the processing of relative clause attachment ambiguities. We propose that the second factor involved in the processing of these and related constructions is the principle of Predicate Proximity, according to which attachments are preferred to be as structurally close to the head of a predicate phrase as possible, and we further consider the origins and predictions of the theory combining these two factors.

The relationship between the frequency and the processing complexity of linguistic structure

In this paper the relative frequencies of the possible resolutions of ambiguities involving noun phrase attachment sites are compared to the results of off-line psycholinguistic measurements of syntactic complexity. A lack of correlation between the two is observed. It is therefore argued that the comprehension system is distinct from what is driving the frequencies in the corpora. A production heuristic separate from the comprehension system is proposed to account for the observed frequencies.

Recent advances in home infant apnea monitoring

Appropriate and effective nursing intervention is an essential element in determining how the family responds to the monitor in the home. Accurate assessment of the family system and dynamics provides the basis for a plan of care. The family's and infant's specific needs must be addressed. Careful implementation of the plan allows for changes and unexpected outcomes. Frequent evaluation of monitoring is necessary to determine if a change in the plan of care is needed. Recent changes in home apnea monitoring technology are rapidly altering the care of infants at risk for apnea and SIDS. The advent of the documented or recording monitor has the potential to demystify the events occurring while the infant is being monitored. Parents can get answers about their infant as quickly as a telephone call. The clinician can differentiate between a true and a false alarm and reassure the parents accordingly. Documenting false events and shallow-breathing alarms will potentially reduce the duration of monitoring, decreasing costs to the entire health care system. Documented monitoring is a valuable tool for nurses. For the staff nurse, clinical observation can be validated through trending and print out of events can be done at the bedside. For the advanced practice nurse, management of care can become more efficient through remote monitoring via modem. Patient teaching can be followed with immediate feedback. Monitors may assist in allaying anxiety in families who have lost children to SIDS or had an unexpected death in a previous sibling. Families may feel less anxious about having an "at risk" child in the home if the events are continuously being recorded. Length of hospital stay may decrease initially, with fewer rehospitalizations. Nursing research in these areas is necessary. Evaluating events occurring in the home may also help shed light on the enigma of SIDS. Several SIDS deaths have been recorded on documented monitors. If we can pinpoint exactly what takes place prior to and immediately after a SIDS episode, the enigma that has had physicians puzzled for so long may finally begin to unravel.