Analysis of guideline recommendations for treatment of asthma exacerbations in children: a Pediatric Emergency Research Networks (PERN) study

RATIONALE

There is significant practice variation in acute paediatric asthma, particularly severe exacerbations. It is unknown whether this is due to differences in clinical guidelines.

OBJECTIVES

To describe and compare the content and quality of clinical guidelines for the management of acute exacerbations of asthma in children between geographic regions.

METHODS

Observational study of guidelines for the management of acute paediatric asthma from institutions across a global collaboration of six regional paediatric emergency research networks.

MEASUREMENTS AND MAIN RESULTS

158 guidelines were identified. Half provided recommendations for at least two age groups, and most guidelines provided treatment recommendations according to asthma severity.There were consistent recommendations for the use of inhaled short-acting beta-agonists and systemic corticosteroids. Inhaled anticholinergic therapy was recommended in most guidelines for severe and critical asthma, but there were inconsistent recommendations for its use in mild and moderate exacerbations. Other inhaled therapies such as helium-oxygen mixture (Heliox) and nebulised magnesium were inconsistently recommended for severe and critical illness.Parenteral bronchodilator therapy and epinephrine were mostly reserved for severe and critical asthma, with intravenous magnesium most recommended. There were regional differences in the use of other parenteral bronchodilators, particularly aminophylline.Guideline quality assessment identified high ratings for clarity of presentation, scope and purpose, but low ratings for stakeholder involvement, rigour of development, applicability and editorial independence.

CONCLUSIONS

Current guidelines for the management of acute paediatric asthma exacerbations have substantial deficits in important quality domains and provide limited and inconsistent guidance for severe exacerbations.

Implementation of a pediatric in situ, train-the-trainer simulation program in general emergency departments

Background

Most children receive emergency care in general emergency departments (EDs). Pediatric resuscitations require specific equipment and weight-based dosing that may be less familiar to general ED healthcare professionals. In situ simulation (ISS) improves teamwork and problem solving, and it may identify latent safety threats. This innovative program brought academic faculty to participating hospitals and taught simulation principles in a small-group environment. This format removed many of the barriers to implementing simulations for general EDs and was intended to teach principles for utilizing simulation to meet unique departmental needs.

Methods

Using the Consolidated Framework for Implementation Research (CFIR) framework, ED teams at eight hospitals participated in a train-the-trainer program from 2016 to 2020 intended to help them implement their own ISSs. Training covered benefits of ISS, use of simulation for identifying latent safety threats, debriefing principles, and potential safety risks of ISS. Faculty also provided on-site mentoring during the implementation phase. We identified factors and barriers that contributed to the successful adoption of an ISS program.

Results

Most hospitals continued their ISS program after the study ended. Several themes emerged as pearls and pitfalls to implementing a train-the-trainer program. Successful teams had strong nursing and physician leadership participation, and team members had positive working relationships with early positive feedback which encouraged future ISS implementation. Barriers to simulation included high staff turnover of nurses and physicians as well as social distancing protocols related to infection control.

Conclusions

Academic EDs can partner with general EDs to implement a train-the-trainer simulation program. We describe facilitators and barriers to implementing a train-the-trainer ISS program in general EDs to improve emergency care for high-risk, low-frequency events.

Race, racism, and antiracism in emergency medicine: A scoping review of the literature and research agenda for the future

OBJECTIVES

The objective was to conduct a scoping review of the literature and develop consensus-derived research priorities for future research inquiry in an effort to (1) identify and summarize existing research related to race, racism, and antiracism in emergency medicine (EM) and adjacent fields and (2) set the agenda for EM research in these topic areas.

METHODS

A scoping review of the literature using PubMed and EMBASE databases, as well as review of citations from included articles, formed the basis for discussions with community stakeholders, who in turn helped to inform and shape the discussion and recommendations of participants in the Society for Academic Emergency Medicine (SAEM) consensus conference. Through electronic surveys and two virtual meetings held in April 2021, consensus was reached on terminology, language, and priority research questions, which were rated on importance or impact (highest, medium, lower) and feasibility or ease of answering (easiest, moderate, difficult).

RESULTS

A total of 344 articles were identified through the literature search, of which 187 met inclusion criteria; an additional 34 were identified through citation review. Findings of racial inequities in EM and related fields were grouped in 28 topic areas, from which emerged 44 key research questions. A dearth of evidence for interventions to address manifestations of racism in EM was noted throughout.

CONCLUSIONS

Evidence of racism in EM emerged in nearly every facet of our literature. Key research priorities identified through consensus processes provide a roadmap for addressing and eliminating racism and other systems of oppression in EM.

Guiding Fellows to Independent Practice: Current Trends in Pediatric Emergency Medicine Fellow Supervision

BACKGROUND

Recent studies highlight the importance of physician readiness to practice beyond graduate training. The Accreditation Council for Graduate Medical Education mandates that pediatric emergency medicine (PEM) fellows be prepared for independent practice by allowing "progressive responsibility for patient care." Prior unpublished surveys of program directors (PDs) indicate variability in approaches to provide opportunities for more independent practice during fellowship training.

OBJECTIVES

The aims of the study were to describe practices within PEM fellowship programs allowing fellows to work without direct supervision and to identify any barriers to independent practice in training.

DESIGN/METHODS

An anonymous electronic survey of PEM fellowship PDs was performed. Survey items were developed using an iterative modified Delphi process and pilot tested. Close-ended survey responses and demographic variables were summarized with descriptive statistics. Responses to open-ended survey items were reviewed and categorized by theme.

RESULTS

Seventy two of 84 PDs (88%) responded to the survey; however, not all surveys were completed. Of the 68 responses to whether fellows could work without direct supervision (as defined by the Accreditation Council for Graduate Medical Education) during some part of their training, 31 (45.6%) reported that fellows did have this opportunity. In most programs, clinical independence was conditional on specific measures including the number of clinical hours completed, milestone achievement, and approval by the clinical competency committee. Reported barriers to fellow practice without direct oversight included both regulatory and economic constraints.

CONCLUSIONS

Current training practices that provide PEM fellows with conditional clinical independence are variable. Future work should aim to determine best practices of entrustment, identify ideal transition points, and mitigate barriers to graduated responsibility.

Omphalitis and Concurrent Serious Bacterial Infection

OBJECTIVE

Describe the clinical presentation, prevalence of concurrent serious bacterial infection (SBI), and outcomes among infants with omphalitis.

METHODS

Within the Pediatric Emergency Medicine Collaborative Research Committee, 28 sites reviewed records of infants ≤90 days of age with omphalitis seen in the emergency department from January 1, 2008, to December 31, 2017. Demographic, clinical, laboratory, treatment, and outcome data were summarized.

RESULTS

Among 566 infants (median age 16 days), 537 (95%) were well-appearing, 64 (11%) had fever at home or in the emergency department, and 143 (25%) had reported fussiness or poor feeding. Blood, urine, and cerebrospinal fluid cultures were collected in 472 (83%), 326 (58%), and 222 (39%) infants, respectively. Pathogens grew in 1.1% (95% confidence interval [CI], 0.3%-2.5%) of blood, 0.9% (95% CI, 0.2%-2.7%) of urine, and 0.9% (95% CI, 0.1%-3.2%) of cerebrospinal fluid cultures. Cultures from the site of infection were obtained in 320 (57%) infants, with 85% (95% CI, 80%-88%) growing a pathogen, most commonly methicillin-sensitive Staphylococcus aureus (62%), followed by methicillin-resistant Staphylococcus aureus (11%) and Escherichia coli (10%). Four hundred ninety-eight (88%) were hospitalized, 81 (16%) to an ICU. Twelve (2.1% [95% CI, 1.1%-3.7%]) had sepsis or shock, and 2 (0.4% [95% CI, 0.0%-1.3%]) had severe cellulitis or necrotizing soft tissue infection. There was 1 death. Serious complications occurred only in infants aged <28 days.

CONCLUSIONS

In this multicenter cohort, mild, localized disease was typical of omphalitis. SBI and adverse outcomes were uncommon. Depending on age, routine testing for SBI is likely unnecessary in most afebrile, well-appearing infants with omphalitis.

The Path Forward: Using Metrics to Promote Equitable Work Environments

Women continue to be underrepresented in medicine, especially in senior leadership positions, and they experience challenges related to gender bias and sexual harassment. Women who are members of multiple groups that experience marginalization, including, for example, women who are American Indian, Alaskan native, indigenous, Black, or Hispanic, face a compounded challenge. In this article, we explore how institutions and professional organizations in medicine can use metrics to better understand the structural disparities that create and promote gender inequity in the work environment and how to employ these metrics to track progress in narrowing these gaps. Examples in health care (clinical medicine, scientific organizations, scientific publishing), business, and law are used to illustrate how impactful metrics can promote accountability when coupled with transparent reporting.

Neonatal Mastitis and Concurrent Serious Bacterial Infection

OBJECTIVES

Describe the clinical presentation, prevalence, and outcomes of concurrent serious bacterial infection (SBI) among infants with mastitis.

METHODS

Within the Pediatric Emergency Medicine Collaborative Research Committee, 28 sites reviewed records of infants aged ≤90 days with mastitis who were seen in the emergency department between January 1, 2008, and December 31, 2017. Demographic, clinical, laboratory, treatment, and outcome data were summarized.

RESULTS

Among 657 infants (median age 21 days), 641 (98%) were well appearing, 138 (21%) had history of fever at home or in the emergency department, and 63 (10%) had reported fussiness or poor feeding. Blood, urine, and cerebrospinal fluid cultures were collected in 581 (88%), 274 (42%), and 216 (33%) infants, respectively. Pathogens grew in 0.3% (95% confidence interval [CI] 0.04-1.2) of blood, 1.1% (95% CI 0.2-3.2) of urine, and 0.4% (95% CI 0.01-2.5) of cerebrospinal fluid cultures. Cultures from the site of infection were obtained in 335 (51%) infants, with 77% (95% CI 72-81) growing a pathogen, most commonly methicillin-resistant Staphylococcus aureus (54%), followed by methicillin-susceptible S aureus (29%), and unspecified S aureus (8%). A total of 591 (90%) infants were admitted to the hospital, with 22 (3.7%) admitted to an ICU. Overall, 10 (1.5% [95% CI 0.7-2.8]) had sepsis or shock, and 2 (0.3% [95% CI 0.04-1.1]) had severe cellulitis or necrotizing soft tissue infection. None received vasopressors or endotracheal intubation. There were no deaths.

CONCLUSIONS

In this multicenter cohort, mild localized disease was typical of neonatal mastitis. SBI and adverse outcomes were rare. Evaluation for SBI is likely unnecessary in most afebrile, well-appearing infants with mastitis.

Using In Situ Simulations to Improve Pediatric Patient Safety in Emergency Departments

PROBLEM

Given the complex interaction among patients, individual providers, health care teams, and the clinical environment, patient safety events with serious consequences are most likely to occur in intensive care units, operating rooms, and emergency departments (EDs). With low-frequency, high-risk events such as pediatric resuscitations, health care teams working in EDs may not have the clinical opportunity to identify deficiencies, review and reinforce knowledge and skills, and problem solve in authentic clinical conditions. Without creating opportunities to safely practice, hospitals run the risk of having health care teams and environments that are not prepared to provide optimal patient care.

APPROACH

Researchers employed a case series design and used a train-the-trainer model for in situ simulation. They trained health care professionals (instructors) in 3 general, nonacademic EDs in the San Francisco Bay area of California to perform pediatric resuscitation in situ simulations in 2018-2019. In situ simulations occur in the clinical work environment with simulation participants (teams) who are health care professionals taking care of actual patients.

OUTCOMES

Teams made up of physicians, nurses, and ED technicians were evaluated for clinical performance, teamwork, and communication during in situ simulations conducted by instructors at baseline, 6 months, and 12 months. Debriefing after the simulations identified multiple latent safety threats (i.e., unidentified potential safety hazards) that were previously unknown. Each ED's pediatric readiness-its ability to provide emergency care for children-was evaluated at baseline and 12 months.

NEXT STEPS

The authors will continue to monitor and examine the impact and sustainability of the pediatric in situ simulation program on pediatric readiness scores and its possible translation to other high-risk clinical settings, as well as explore the relationship between in situ simulations and patient outcomes.

Protecting the emergency physician workforce during the coronavirus disease 2019 pandemic through precision scheduling at an academic tertiary care trauma center

The coronavirus disease 2019 (COVID-19) pandemic created new emergency physician staffing challenges. Emergency physicians may be taken out of the workforce because of respiratory symptoms or pending severe acute respiratory syndrome coronavirus 2 test results. Vulnerable emergency physician populations with increased risk of serious disease and death from COVID-19 include physicians at older ages; those with chronic medical conditions, including cardiac and pulmonary diseases and immunosuppression; and potentially pregnancy. We present our approach to planning for staffing issues through precision scheduling. We describe the actions taken to protect our vulnerable physicians and maximize our physician coverage. Measures include optimizing workforce; increasing backup call system; adjusting shifts based on patient arrival times, volume, and surge predictions; minimizing exposure to COVID-19 and reduce personal protective equipment use through telemedicine, huddles, and, creating lower risk emergency department care areas; and standardizing intubations to limit exposure.

Invasive Bacterial Infections in Afebrile Infants Diagnosed With Acute Otitis Media

OBJECTIVES

To determine the prevalence of invasive bacterial infections (IBIs) and adverse events in afebrile infants with acute otitis media (AOM).

METHODS

We conducted a 33-site cross-sectional study of afebrile infants ≤90 days of age with AOM seen in emergency departments from 2007 to 2017. Eligible infants were identified using emergency department diagnosis codes and confirmed by chart review. IBIs (bacteremia and meningitis) were determined by the growth of pathogenic bacteria in blood or cerebrospinal fluid (CSF) culture. Adverse events were defined as substantial complications resulting from or potentially associated with AOM. We used generalized linear mixed-effects models to identify factors associated with IBI diagnostic testing, controlling for site-level clustering effect.

RESULTS

Of 5270 infants screened, 1637 met study criteria. None of the 278 (0%; 95% confidence interval [CI]: 0%-1.4%) infants with blood cultures had bacteremia; 0 of 102 (0%; 95% CI: 0%-3.6%) with CSF cultures had bacterial meningitis; 2 of 645 (0.3%; 95% CI: 0.1%-1.1%) infants with 30-day follow-up had adverse events, including lymphadenitis (1) and culture-negative sepsis (1). Diagnostic testing for IBI varied across sites and by age; overall, 278 (17.0%) had blood cultures, and 102 (6.2%) had CSF cultures obtained. Compared with infants 0 to 28 days old, older infants were less likely to have blood cultures (P < .001) or CSF cultures (P < .001) obtained.

CONCLUSION

Afebrile infants with clinician-diagnosed AOM have a low prevalence of IBIs and adverse events; therefore, outpatient management without diagnostic testing may be reasonable.

Emergency department implementation of abbreviated magnetic resonance imaging for pediatric traumatic brain injury

Pediatric head injury is a common presenting complaint in the emergency department (ED), often requiring neuroimaging or ED observation for diagnosis. However, the traditional diagnostic neuroimaging modality, head computed tomography (CT), is associated with radiation exposure while prolonged ED observation impacts patient flow and resource utilization. Recent scientific literature supports abbreviated, or focused and shorter, brain magnetic resonance imaging (MRI) as a feasible and accurate diagnostic alternative to CT for traumatic brain injury. However, this is a relatively new application and its use is not widespread. The aims of this review are to describe the science and applications of abbreviated brain MRI and report a model protocol's development and ED implementation in the evaluation of children with head injury for replication in other institutions.

Acute severe paediatric asthma: study protocol for the development of a core outcome set, a Pediatric Emergency Reserarch Networks (PERN) study

BACKGROUND

Acute severe childhood asthma is an infrequent, but potentially life-threatening emergency condition. There is a wide range of different approaches to this condition, with very little supporting evidence, leading to significant variation in practice. To improve knowledge in this area, there must first be consensus on how to conduct clinical trials, so that valid comparisons can be made between future studies. We have formed an international working group comprising paediatricians and emergency physicians from North America, Europe, Asia, the Middle East, Africa, South America, Central America, Australasia and the United Kingdom.

METHODS/DESIGN

A 5-stage approach will be used: (1) a comprehensive list of outcomes relevant to stakeholders will be compiled through systematic reviews and qualitative interviews with patients, families, and clinicians; (2) Delphi methodology will be applied to reduce the comprehensive list to a core outcome set; (3) we will review current clinical practice guidelines, existing clinical trials, and literature on bedside assessment of asthma severity. We will then identify practice differences in tne clinical assessment of asthma severity, and determine whether further prospective work is needed to achieve agreement on inclusion criteria for clinical trials in acute paediatric asthma in the emergency department (ED) setting; (4) a retrospective chart review in Australia and New Zealand will identify the incidence of serious clinical complications such as intubation, ICU admission, and death in children hospitalized with acute severe asthma. Understanding the incidence of such outcomes will allow us to understand how common (and therefore how feasible) particular outcomes are in asthma in the ED setting; and finally (5) a meeting of the Pediatric Emergency Research Networks (PERN) asthma working group will be held, with invitation of other clinicians interested in acute asthma research, and patients/families. The group will be asked to achieve consensus on a core set of outcomes and to make recommendations for the conduct of clinical trials in acute severe asthma. If this is not possible, the group will agree on a series of prioritized steps to achieve this aim.

DISCUSSION

The development of an international consensus on core outcomes is an important first step towards the development of consensus guidelines and standardised protocols for randomized controlled trials (RCTs) in this population. This will enable us to better interpret and compare future studies, reduce risks of study heterogeneity and outcome reporting bias, and improve the evidence base for the management of this important condition.

2018 Academic Emergency Medicine Consensus Conference: A Workforce Development Research Agenda for Pediatric Care in the Emergency Department

Each year, more than 30 million children visit U.S. emergency departments (EDs). Although the number of pediatric emergency medicine specialists continues to rise, the vast majority of children are cared for in general EDs outside of children's hospitals. The diverse workforce of care providers for children must possess the knowledge, experience, skills, and systemic support necessary to deliver excellent pediatric emergency care. There is a crucial need to understand the factors that drive the professional development and support systems of this diverse workforce. Through the iterative process culminating with the 2018 Academic Emergency Medicine consensus conference, we have identified five key research themes and prioritized a specific research agenda. These themes represent critical gaps in our understanding of the development and maintenance of the pediatric emergency care workforce and allow for a prioritization of future research efforts. Only by more fully understanding the gaps in workforce needs, and the necessary steps to address these gaps, can outcomes be optimized for children in need of emergency care.

Acute Rheumatic Fever: An Evidence-Based Approach To Diagnosis And Initial Management

Acute rheumatic fever is an inflammatory reaction involving the joints, heart, and nervous system that occurs after a group A streptococcal infection. It typically presents as a febrile illness with clinical manifestations that could include arthritis, carditis, skin lesions, or abnormal movements. Of these, the cardiac manifestations of acute rheumatic fever are most concerning, as children may present in acute heart failure and may go on to develop valvular insufficiency or stenosis. Because this is a rare presentation to emergency departments in developed countries, it is crucial for clinicians to keep a broad differential when presented with clinical presentations suspicious for acute rheumatic fever. This issue focuses on the clinical evaluation and treatment of patients with acute rheumatic fever by offering a thorough review of the literature on diagnosis and recommendations on appropriate treatment.

The greater good: how supervising physicians make entrustment decisions in the pediatric emergency department

BACKGROUND

Graduate medical education is transitioning to the use of entrustable professional activities to contextualize educational competencies. Factors influencing entrustment decisions have been reported in adult medicine. Knowing how such decisions are made in pediatrics is critical to this transition.

PURPOSE

To understand how supervisors determine the level of procedural supervision to provide a resident, taking into consideration simulation performance; to understand factors that affect supervisors' transparency to parents about residents' procedural experience.

METHODS

We conducted 18 one-on-one interviews with supervisors in a tertiary care pediatric emergency department, iteratively revising interview questions as patterns in the data were elucidated. Two researchers independently coded transcripts and then met with the investigative team to refine codes and create themes.

RESULTS

Five factors influenced supervisors' entrustment decisions: 1) resident characteristics that include self-reported confidence, seniority, and prior interactions with the resident; 2) supervisor style; 3) nature of the procedure/characteristics of the patient; 4) environmental factors; and 5) parental preferences. Supervisors thought that task-based simulators provided practice opportunities but that simulated performance did not provide evidence for entrustment. Supervisors reported selectively omitting details about a resident's experience level to families to optimize experiential learning for residents they entrusted to perform a procedure.

CONCLUSIONS

In pediatrics, supervisors consider various factors when making decisions regarding resident procedural readiness, including parental preferences. An educational system using entrustable professional activities may facilitate holistic assessment and foster expertise-informed decisions about residents' progression toward entrustment; such a system may also lessen supervisors' need to omit information to parents about residents' procedural readiness.

Global health and emergency care: a postgraduate medical education consensus-based research agenda

Global emergency medicine (EM) is a rapidly growing field within EM, as evidenced by the increasing number of trainees and clinicians pursuing additional experiences in global health and emergency care. In particular, many trainees now desire opportunities at the postgraduate level by way of global EM fellowship programs. Despite this growing popularity, little is known of the effects of postgraduate training in global health and emergency care on learners and patients in the United States and abroad. During the 2013 Academic Emergency Medicine consensus conference on global health and emergency care, a group of leading educators at the postgraduate medical education level convened to generate a research agenda of pressing questions to be answered in this area. The consensus-based research agenda is presented in this article.

The role of graduate medical education in global health: proceedings from the 2013 Academic Emergency Medicine consensus conference

The past 40 years have seen expanded development of emergency medicine (EM) postgraduate residency training programs worldwide. An important part of this educational experience is the ability of resident trainees to participate in experiences abroad. However, little is known about how these experiences shape trainees and the populations they serve. During the 2013 Academic Emergency Medicine consensus conference, a group of educators met to define and outline current trends in graduate medical education (GME) emergency care research. The authors discuss future research questions bridging the gap of GME and global health.

Chk2 activation dependence on Nbs1 after DNA damage

The checkpoint kinase Chk2 has a key role in delaying cell cycle progression in response to DNA damage. Upon activation by low-dose ionizing radiation (IR), which occurs in an ataxia telangiectasia mutated (ATM)-dependent manner, Chk2 can phosphorylate the mitosis-inducing phosphatase Cdc25C on an inhibitory site, blocking entry into mitosis, and p53 on a regulatory site, causing G(1) arrest. Here we show that the ATM-dependent activation of Chk2 by gamma- radiation requires Nbs1, the gene product involved in the Nijmegen breakage syndrome (NBS), a disorder that shares with AT a variety of phenotypic defects including chromosome fragility, radiosensitivity, and radioresistant DNA synthesis. Thus, whereas in normal cells Chk2 undergoes a time-dependent increased phosphorylation and induction of catalytic activity against Cdc25C, in NBS cells null for Nbs1 protein, Chk2 phosphorylation and activation are both defective. Importantly, these defects in NBS cells can be complemented by reintroduction of wild-type Nbs1, but neither by a carboxy-terminal deletion mutant of Nbs1 at amino acid 590, unable to form a complex with and to transport Mre11 and Rad50 in the nucleus, nor by an Nbs1 mutated at Ser343 (S343A), the ATM phosphorylation site. Chk2 nuclear expression is unaffected in NBS cells, hence excluding a mislocalization as the cause of failed Chk2 activation in Nbs1-null cells. Interestingly, the impaired Chk2 function in NBS cells correlates with the inability, unlike normal cells, to stop entry into mitosis immediately after irradiation, a checkpoint abnormality that can be corrected by introduction of the wild-type but not the S343A mutant form of Nbs1. Altogether, these findings underscore the crucial role of a functional Nbs1 complex in Chk2 activation and suggest that checkpoint defects in NBS cells may result from the inability to activate Chk2.

ATM-dependent phosphorylation of nibrin in response to radiation exposure

Mutations in the gene ATM are responsible for the genetic disorder ataxia-telangiectasia (A-T), which is characterized by cerebellar dysfunction, radiosensitivity, chromosomal instability and cancer predisposition. Both the A-T phenotype and the similarity of the ATM protein to other DNA-damage sensors suggests a role for ATM in biochemical pathways involved in the recognition, signalling and repair of DNA double-strand breaks (DSBs). There are strong parallels between the pattern of radiosensitivity, chromosomal instability and cancer predisposition in A-T patients and that in patients with Nijmegen breakage syndrome (NBS). The protein defective in NBS, nibrin (encoded by NBS1), forms a complex with MRE11 and RAD50 (refs 1,2). This complex localizes to DSBs within 30 minutes after cellular exposure to ionizing radiation (IR) and is observed in brightly staining nuclear foci after a longer period of time. The overlap between clinical and cellular phenotypes in A-T and NBS suggests that ATM and nibrin may function in the same biochemical pathway. Here we demonstrate that nibrin is phosphorylated within one hour of treatment of cells with IR. This response is abrogated in A-T cells that either do not express ATM protein or express near full-length mutant protein. We also show that ATM physically interacts with and phosphorylates nibrin on serine 343 both in vivo and in vitro. Phosphorylation of this site appears to be functionally important because mutated nibrin (S343A) does not completely complement radiosensitivity in NBS cells. ATM phosphorylation of nibrin does not affect nibrin-MRE11-RAD50 association as revealed by radiation-induced foci formation. Our data provide a biochemical explanation for the similarity in phenotype between A-T and NBS.

Cup feeding: an alternative to bottle feeding in a neonatal intensive care unit

Cup feeding has been suggested as an alternative to bottle feeding to help promote breastfeeding by avoiding nipple confusion. To demonstrate the possibility and utility of cup feeding, records of 59 preterm and low birthweight babies (born before 37 weeks' gestation) admitted to a neonatal intensive care unit (NICU) from May 1995 to April 1996 were analyzed. Feeding was initiated on cup if swallowing was present and cup feeding was possible as early as 29 weeks' gestational age with a birthweight of 900 g. In the case of five infants (38 per cent) in the gestational age group 28-30 weeks, 19 infants (52 per cent) in the 31-34 weeks' gestation group, and six (56 per cent) in the 35-37 weeks' gestation group, feeding could be commenced directly with a cup. Out of 59 infants, 33 infants (56 per cent) could be discharged on exclusive breastfeeding. It was concluded that cup feeding is a useful alternative to bottle feeding and an effective method of feeding preterm and small infants in NICU. Cup feeding allows successful breastfeeding without causing 'nipple confusion'.

Calpain activation is upstream of caspases in radiation-induced apoptosis

The molecular events involved in apoptosis induced by ionizing radiation remain unresolved. In this paper we show that the cleavage of fodrin to a 150 kDa fragment is an early proteolytic event in radiation-induced apoptosis in the Burkitts' Lymphoma cell line BL30A and requires 100 microM zVAD-fmk for inhibition. Caspases-1, -3, -6 and -7 were shown to cleave fodrin to the 150 kDa fragment in vitro and all were inhibited by 10 microM zVAD-fmk. We also show that the in vitro cleavage of fodrin by calpain is inhibited by 100 microM zVAD-fmk as was the calpain-mediated hydrolysis of casein. We demonstrate that calpain is activated within 15 min after radiation exposure, concomitant with the cleavage of fodrin to the 150 kDa fragment whereas caspase-3 is activated at 2 h correlating with the cleavage of fodrin to the 120 kDa fragment. These results support a role for calpain in the early phases of the radiation-induced apoptosis pathway, upstream of the caspases.

Mineralocorticoid blockade reduces vascular injury in stroke-prone hypertensive rats

Chronic treatment of saline-drinking stroke-prone spontaneously hypertensive rats (SHRSP) with agents that interfere with the formation or actions of angiotensin II (Ang II) prevents the development of stroke and renal vascular damage. Ang II, in addition to its direct vascular effects, stimulates the synthesis and release of aldosterone. To assess the role of aldosterone in the development of pathologic changes in these rats, we implanted time-release pellets containing 200 mg of the mineralocorticoid receptor antagonist, spironolactone, into 14 SHRSP at 7.5 weeks of age. Eight SHRSP littermates received placebo pellets. Over the period of study (3 to 4 weeks), systolic blood pressure (SBP) was not different between the groups. Spironolactone did not enhance water and electrolyte excretion. All placebo-treated SHRSP developed marked proteinuria (150+/-6 mg/d) whereas in spironolactone-treated SHRSP, urinary protein excretion (UPE) averaged 39+/-9 mg/d (P<.0001). In a second study to assess effects on survival, 6 SHRSP received spironolactone (10 mg/kg/d) and 6 received vehicle. All but one of the control rats displayed signs of stroke and died by 16 weeks of age, while the spironolactone-treated SHRSP remained asymptomatic through 19 weeks of age (P<.03). At 16 weeks of age, spironolactone-treated SHRSP were severely hypertensive (247+/-3 mm Hg), yet UPE remained at baseline levels. In contrast, preterminal UPE averaged 136+/-13 mg/d in control rats (P<.0001). In both studies, histopathologic examination revealed a marked protective effect of spironolactone against the development of malignant nephrosclerotic and cerebrovascular lesions. These observations indicate a vascular and end organ protective effect of spironolactone in the absence of lowered blood pressure in saline-drinking SHRSP and are consistent with a major role for mineralocorticoids as hormonal mediators of vascular injury.

Distinct genetic groups of Giardia intestinalis distinguished by restriction fragment length polymorphisms

The taxonomic status of the parasitic protozoal species Giardia intestinalis depends on the morphological similarity of all Giardia isolated from humans and the presumption that Giardia are host-specific. On the basis of electrophoretic data derived from examination of 26 enzyme loci in Australian isolates, it has been proposed that G. intestinalis is a species complex comprising three or four genetically distinct (but morphologically cryptic) species. These received the tentative designations of genetic groups I-IV (R. H. Andrews, M. Adams, P. F. L. Boreham, G. Mayrhofer & B. P. Meloni. International Journal for Parasitology 19, 183-190, 1989). In the present study, two unrelated DNA probes (one specific for a gene encoding a trophozoite surface protein, the other detecting a non-coding repetitive sequence within the G. intestinalis genome) were used in Southern hybridization analyses to examine 10 axenic isolates of G. intestinalis, established from diverse geographical regions in Australia, together with the Portland-1 isolate from the USA. Both probes identified every isolate unambiguously as belonging to one or other of two genetic clusters. Electrophoretic analysis of the same samples indicated that these clusters correspond to the previously defined genetic groups I and II. No heterogeneity was apparent within the seven group I isolates using either probe. However, when probed with the repetitive sequence, the four isolates belonging to group II exhibited small differences in banding patterns, suggesting that this group may be less homogeneous than group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Wheat germ agglutinin specifically inhibits formyl peptide-induced polymorphonuclear leukocyte chemotaxis

Evidence that surface membrane glycoproteins of polymorphonuclear leukocytes (PMN) are involved in stimulus-response coupling prompted us to examine effects on these cells of various plant lectins. We have found that wheat germ agglutinin (WGA) (1.0 microgram/ml) completely, specifically, and irreversibly inhibits directed migration (chemotaxis) of human PMN toward the synthetic peptide, N-formylmethionyl-leucyl-phenylalanine (FMLP) (0.1 to 100 nM). This effect of WGA was not shared by subagglutinating concentrations of either concanavalin A or Bandeirea simplicifolia lectin. In contrast to its effects on FMLP-induced chemotaxis, WGA did not influence other FMLP-induced PMN responses (i.e., selective discharge of lysosomal enzymes from cytochalasin B-treated cells, generation of superoxide anion radical(s). WGA also did not influence PMN chemotactic responses to either the complement-derived peptide, C5a, or the lipoxygenase product, leukotriene B4. Inhibition of FMLP-induced chemotaxis by WGA was not reversed by washing WGA-treated cells, but was reversed (and prevented) by N-acetyl-D-glucosamine (not by N-acetyl-D-galactosamine or mannosamine). WGA did not affect either orientation or stimulated random motility of PMN, and did not interfere with specific binding to PMN of (3H)-FMLP. A derivative of WGA with 10-fold less agglutinating activity for human erythrocytes was prepared by treating the native lectin with cyanogen bromide and formic acid. The derivative also inhibited FMLP-induced PMN chemotaxis specifically and selectively. These data suggest that WGA specifically inhibits FMLP-induced PMN chemotaxis by attaching to N-acetyl-D-glucosamine residues at a locus on the PMN plasma membrane that is distinct from the binding site of the FMLP receptor.

Wheat germ agglutinin specifically inhibits formyl peptide-induced polymorphonuclear leukocyte chemotaxis

Evidence that surface membrane glycoproteins of polymorphonuclear leukocytes (PMN) are involved in stimulus-response coupling prompted us to examine effects on these cells of various plant lectins. We have found that wheat germ agglutinin (WGA) (1.0 microgram/ml) completely, specifically, and irreversibly inhibits directed migration (chemotaxis) of human PMN toward the synthetic peptide, N-formylmethionyl-leucyl-phenylalanine (FMLP) (0.1 to 100 nM). This effect of WGA was not shared by subagglutinating concentrations of either concanavalin A or Bandeirea simplicifolia lectin. In contrast to its effects on FMLP-induced chemotaxis, WGA did not influence other FMLP-induced PMN responses (i.e., selective discharge of lysosomal enzymes from cytochalasin B-treated cells, generation of superoxide anion radical(s). WGA also did not influence PMN chemotactic responses to either the complement-derived peptide, C5a, or the lipoxygenase product, leukotriene B4. Inhibition of FMLP-induced chemotaxis by WGA was not reversed by washing WGA-treated cells, but was reversed (and prevented) by N-acetyl-D-glucosamine (not by N-acetyl-D-galactosamine or mannosamine). WGA did not affect either orientation or stimulated random motility of PMN, and did not interfere with specific binding to PMN of (3H)-FMLP. A derivative of WGA with 10-fold less agglutinating activity for human erythrocytes was prepared by treating the native lectin with cyanogen bromide and formic acid. The derivative also inhibited FMLP-induced PMN chemotaxis specifically and selectively. These data suggest that WGA specifically inhibits FMLP-induced PMN chemotaxis by attaching to N-acetyl-D-glucosamine residues at a locus on the PMN plasma membrane that is distinct from the binding site of the FMLP receptor.