Timely administration of antibiotics in febrile neutropenia per updated ASCO/IDSA guidelines

41

Background: Current ASCO guidelines for management of febrile neutropenia (FN) recommend initial antibiotic administration within one hour of triage, and initial assessment within 15 minutes of triage for patients presenting with FN within 6 weeks of chemotherapy. The University of Illinois Cancer Center (UICC) implemented an early identification and management strategy in the ambulatory setting for FN in 2017, with success in increasing the percentage of FN patients receiving antibiotics within 2 hours from 50% to 92% over a 6 months (05/2017-11/2017) period. Given updated joint ASCO/IDSA guidelines, we aimed to increase percentage of FN patients receiving antibiotics within 1 hour from 56% to more than 90% over 16 months. Methods: A multidisciplinary team involving oncology, hematology (attendings and fellows), pharmacy, and nursing met quarterly to review FN cases including time to antibiotic administration and documentation of prompt assessment. Two Plan-Do-Study-Act (PDSA) cycles were completed, including development and deployment of an electronic medical record automated order set and targeted education for fellows and nurses. Results: Between 12/17 and 04/19, of 7 patients with FN, 100% (N = 7) received antibiotics in clinic. The percentage of FN patients receiving antibiotics within 1 hour of triage post first and second interventions was as follows: 25% (N = 1), 100% (N = 4). 100% (N = 7) of FN patients had documentation of prompt assessment, but time from triage was not specified. Conclusions: We were successful in improving the percentage of FN patients receiving antibiotics from 56% to more than 90% over 16 months. We are targeting our next PDSA cycle to increase assessments within 15 minutes of triage. Additional future interventions include tailoring antibiotics based on FN with low or high risk of complication via focus group and root case analyses discussion with our attendings, fellows, and nurses, and collaborating with ED on a standard care pathway for FN management.

Cavernous Haemangioma with Kasabach-Merritt Syndrome: Treatment with Alpha-Interferon

A small number of patients with haemangioma need treatment for serious complications such as Kasabach-Merritt syndrome, cardiac failure and obstruction of the airway. We report on the management of an infant with Kasabach-Merritt syndrome.

Documentation of pharmacist-provided patient education for oral chemotherapy

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Background: Pharmacist-provided patient education for oral chemotherapy is poorly documented in patient electronic medical records (EMR) at UIC Oncology Pharmacy. At baseline, 41% of patients who started new therapy with selected oral chemotherapies had a patient education note documented by a pharmacist in their EMR. Our aim is to provide and document patient education for at least 90% of patients who start new oral chemotherapy and fill their prescriptions at UIC Oncology Pharmacy over three months. The importance of patient counseling and documentation is recognized by the Quality Oncology Practice Initiative (QOPI) group. Approximately 25% of patients undergoing chemotherapy are on oral chemotherapy. (Deutsch S, Koerner P, Miller RT, Craft Z, Fancher K. Utilization patterns for oral oncology medications in a specialty pharmacy cycle management program. J Oncol Pharm Pract. 2014;0:1-8.) Methods: A multi-disciplinary team performed an affinity sort and created a process map to identify areas of intervention. The first intervention was labelling prescription bags to identify them as oral chemotherapy prescriptions that require counseling by a pharmacist. Data was collected after two weeks. Results: At the completion of the first PDSA cycle, 40% of patients who started new oral chemotherapy had a documented patient education note written by a pharmacist in their EMR. Documentation of education was performed on the day of pick-up in 89% of cases. Table 1 shows the percentage of notes that included the elements recognized by QOPI standards: documentation of start date, adherence, and adverse effects. Conclusions: Documentation of patient education for oral chemotherapy should be a well-integrated component of ambulatory pharmacy practice. A second PDSA cycle is planned to increase rates of documentation by utilizing the pharmacy resident to perform patient counseling and documentation. Future interventions will be aimed at improving the quality of the data included in the documented notes. [Table: see text]

Evaluation of oral chemotherapy prescribing at an outpatient oncology clinic

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Background: Oral chemotherapy’s exponentially increasing role in the treatment of malignancies continues to pose unique challenges to oncology. The American Society of Clinical Oncology (ASCO) and Oncology Nursing Society (ONS) drafted measures in the Chemotherapy Administration Safety Standards that help address some of these issues concerning oral chemotherapy. There is a lack of data describing the prescribing process for oral chemotherapy. In a retrospective chart review, prescriptions at a hospital-based outpatient oncology center were evaluated for completeness of prescribing and follow up measures. Methods: A retrospective chart review of ten oral chemotherapy medications from May 2012 to July 2012 was conducted. The primary outcome measure was compliance with ASCO and ONS Chemotherapy Administration Safety Standards. A secondary outcome was frequency of pharmacist interventions on oral chemotherapy prescriptions. Results: 412 prescriptions were evaluated. Prescriptions were graded on a scale from 1 to 8. One point was given for inclusion of each of the following: prescribing physician, patient name, drug name, dose, dosing methodology, quantity, refills, and accurate directions. Of all the prescriptions, 23% contained all aspects of a complete prescription. The most common reasons for point deductions were contradictory or unclear directions and allowing refills for oral chemotherapy which should not be refillable. Four percent of prescriptions had a documented pharmacist intervention. Conclusions: This study revealed areas for improvement in the prescribing process of oral chemotherapy. Targeting directions and refill fields within prescription templates will improve compliance with ASCO and ONS standards. This can be accomplished by implementing customized oral chemotherapy prescription templates within treatment plans in the electronic medical record system. Unlike chemotherapy administered in the clinic setting, oral chemotherapy prescriptions are not generally reviewed by oncology trained pharmacists. With the collaboration of medical and nursing staff, a new work flow was implemented which includes pharmacist review of electronic oral chemotherapy prescriptions.

The physiology of sleep in infants

Despite the fact that infants spend more time asleep than awake, an understanding of the importance and effects of sleep on the pathophysiology of illness in infancy is a relatively recent development, and is commonly overlooked in paediatric training. In this review we describe some of the characteristics of sleep in infancy, with particular reference to normal developmental physiology and its relevance to the signs, symptoms and pathophysiology of illness in this age group.

Head covering - a major modifiable risk factor for sudden infant death syndrome: a systematic review

BACKGROUND

Some victims of sudden infant death syndrome (SIDS) are found with their heads covered with bedclothes, but the significance of this is uncertain. The aim of this review is to describe the prevalence of head covering, the magnitude of the risk and how far the suggested causal mechanisms agree with current epidemiological evidence.

METHODS

Systematic review of population-based age-matched controlled studies.

RESULTS

Controlled observations of head covering for the final sleep were found in 10 studies. The pooled prevalence in SIDS victims was 24.6% (95% CI 22.3% to 27.1%) compared to 3.2% (95% CI 2.7% to 3.8%) among controls. The pooled univariate odds ratio (OR) was 9.6 (95% CI 7.9 to 11.7) and the pooled adjusted OR from studies mainly conducted after the fall in SIDS rate was 16.9 (95% CI 12.6 to 22.7). The risk varied in strength but was significant across all studies. In a quarter of cases and controls head covering had occurred at least once previously (pooled adjusted OR = 1.1; 95% CI 0.9 to 1.4). The population attributable risk (27.1%; 95% CI 24.7% to 29.4%) suggests avoiding head covering might reduce SIDS deaths by more than a quarter.

CONCLUSIONS

The epidemiological evidence does not fully support postulated causal mechanisms such as hypoxia, hypercapnoea and thermal stress, but neither does it support the idea that head covering is part of some terminal struggle. Head covering is a major modifiable risk factor associated with SIDS deaths and parental advice to avoid this situation should be emphasised.

Sudden Infant Death Syndrome and the time of death: factors associated with night-time and day-time deaths

OBJECTIVE

To investigate the diurnal occurrence of Sudden Infant Death Syndrome (SIDS) and interaction with established risk factors in the infant sleeping environment.

METHODS

A 3 year population-based case-control study, in five English Health Regions. Parentally defined day-time or night-time deaths of 325 SIDS infants and reference sleep of 1300 age-matched controls.

RESULTS

The majority of SIDS deaths (83%) occurred during night-time sleep, although this was often after midnight and at least four SIDS deaths occurred during every hour of the day. The length of time from last observed alive until the discovery of death ranged from <l to 14 h but was not significantly different from the corresponding sleep period amongst the controls. Amongst the day-time deaths, 38% of the infants were observed alive 30 min prior to discovery and 9% within 10 min. The risk of placing infants asleep on their side was more marked for day-time deaths (interaction: P = 0.0001) nearly half of whom were found prone, while the risk associated with paternal smoking [OR = 3.25 (95%CI: 1.88-5.62)] was more marked for night-time deaths (interaction: P = 0.02). The adverse effect of unsupervised sleep recognized for night-time practice [OR = 5.38 (95%CI: 2.67-10.85)] was also significant for day-time sleep [OR = 10.57 (95%CI: 1.47-75.96)]. Significantly more (P = 0.002) unobserved SIDS infants (24.8%) were found with bedclothes over the head compared with those SIDS infants where a parent was present in the room (11.3%).

CONCLUSIONS

SIDS can happen at any time of the day and relatively quickly. Parents need to be made aware that placing infants supine and keeping them under supervision is equally important for day-time sleeps.

Sudden infant death syndrome and sleeping position in pre-term and low birth weight infants: an opportunity for targeted intervention

AIMS

To determine the combined effects of sudden infant death syndrome (SIDS) risk factors in the sleeping environment for infants who were "small at birth" (pre-term (<37 weeks), low birth weight (<2500 g), or both).

METHODS

A three year population based, case-control study in five former health regions in England (population 17.7 million) with 325 cases and 1300 controls. Parental interviews were carried out after each death and reference sleep of age matched controls.

RESULTS

Of the SIDS infants, 26% were "small at birth" compared to 8% of the controls. The most common sleeping position was supine, for both controls (69%) and those SIDS infants (48%) born at term or > or =2500 g, but for "small at birth" SIDS infants the commonest sleeping position was side (48%). The combined effect of the risk associated with being "small at birth" and factors in the infant sleeping environment remained multiplicative despite controlling for possible confounding in the multivariate model. This effect was more than multiplicative for those infants placed to sleep on their side or who shared the bed with parents who habitually smoked, while for those "small at birth" SIDS who slept in a room separate from the parents, the large combined effect showed evidence of a significant interaction. No excess risk was identified from bed sharing with non-smoking parents for infants born at term or birth weight > or =2500 g.

CONCLUSION

The combined effects of SIDS risk factors in the sleeping environment and being pre-term or low birth weight generate high risks for these infants. Their longer postnatal stay allows an opportunity to target parents and staff with risk reduction messages.

The UK accelerated immunisation programme and sudden unexpected death in infancy: case-control study

OBJECTIVES

To investigate whether the accelerated immunisation programme in the United Kingdom is associated, after adjustment for potential confounding, with the sudden infant death syndrome.

DESIGN

Population based case-control study, February 1993 to March 1996. Parental interviews were conducted for each death and for four controls matched for age, locality, and time of sleep. Immunisation status was taken from records held by the parents.

SETTING

Five regions in England with a combined population of over 17 million.

SUBJECTS

Immunisation details were available for 93% (303/325) of infants whose deaths were attributed to the sudden infant death syndrome (SIDS); 90% (65/72) of infants with explained sudden deaths; and 95% (1515/1588) of controls.

RESULTS

After all potential confounding factors were controlled for, immunisation uptake was strongly associated with a lower risk of SIDS (odds ratio 0.45 (95% confidence interval 0.24 to 0.85)). This difference became non-significant (0.67 (0.31 to 1.43)) after further adjustment for other factors specific to the infant's sleeping environment. Similar proportions of SIDS deaths and reference sleeps (corresponding to the time of day during which the index baby had died) among the controls occurred within 48 hours of the last vaccination (5% (7/149) v 5% (41/822)) and within two weeks (21% (31/149) v 27% (224/822)). No longer term temporal association with immunisation was found (P=0.78). Of the SIDS infants who died within two weeks of vaccination, 16% (5/31) had signs and symptoms of illness that suggested that medical contact was required, compared with 26% (16/61) of the non-immunised SIDS infants of similar age. The findings for the infants who died suddenly and unexpectedly but of explained causes mirrored those for SIDS infants.

CONCLUSIONS

Immunisation does not lead to sudden unexpected death in infancy, and the direction of the relation is towards protection rather than risk.

A framework for modelling in S88 constructs for scheduling purposes

ISA S88.01 [1] [ISA (ANSI/S88.01.1995), Standard batch control; part 1: models and terminology, Instrument Society of America, 1995] is a standard that provides a methodology for the dissemination of a batch into standard models and provides the terminology for defining the control requirements of batch plants. The nature of S88 is such that it is not only applicable to the development of computer control systems for a batch plant, but also could be utilised within batch management software, i.e. scheduling. This paper presents a method of interpreting multi-purpose/product batch plant into S88 constructs to provide an object oriented framework for the research and development of a batch scheduling Matlab tool-box. Such a framework provides a thorough and efficient method of articulating the model to effectively apply automatic scheduling/optimisation methods.

Protein packing: dependence on protein size, secondary structure and amino acid composition

We have used the occluded surface algorithm to estimate the packing of both buried and exposed amino acid residues in protein structures. This method works equally well for buried residues and solvent-exposed residues in contrast to the commonly used Voronoi method that works directly only on buried residues. The atomic packing of individual globular proteins may vary significantly from the average packing of a large data set of globular proteins. Here, we demonstrate that these variations in protein packing are due to a complex combination of protein size, secondary structure composition and amino acid composition. Differences in protein packing are conserved in protein families of similar structure despite significant sequence differences. This conclusion indicates that quality assessments of packing in protein structures should include a consideration of various parameters including the packing of known homologous proteins. Also, modeling of protein structures based on homologous templates should take into account the packing of the template protein structure.

Weight gain and sudden infant death syndrome: changes in weight z scores may identify infants at increased risk

AIMS

To investigate patterns of infant growth that may influence the risk of sudden infant death syndrome (SIDS).

DESIGN

Three year population based case control study with parental interviews for each death and four age matched controls. Growth was measured from prospective weight observations using the British 1990 Growth Reference.

SETTING

Five regions in England (population greater than 17 million, more than 470 000 live births over three years).

SUBJECTS

247 SIDS cases and 1110 controls.

RESULTS

The growth rate from birth to the final weight observation was significantly poorer among the SIDS infants despite controlling for potential confounders (SIDS mean change in weight z score (deltazw) = -0.38 (SD 1.40) v controls = +0.22 (SD 1.10), multivariate: p < 0.0001). Weight gain was poorer among SIDS infants with a normal birth weight (above the 16th centile: odds ratio (OR) = 1.75, 95% confidence interval (CI) 1. 48-2.07, p < 0.0001) than for those with lower birth weight (OR = 1. 09, 95% CI 0.61-1.95, p = 0.76). There was no evidence of increased growth retardation before death.

CONCLUSIONS

Poor postnatal weight gain was independently associated with an increased risk of SIDS and could be identified at the routine six week assessment.

Internal packing of helical membrane proteins

Helix packing is important in the folding, stability, and association of membrane proteins. Packing analysis of the helical portions of 7 integral membrane proteins and 37 soluble proteins show that the helices in membrane proteins have higher packing values (0.431) than in soluble proteins (0.405). The highest packing values in integral membrane proteins originate from small hydrophobic (G and A) and small hydroxyl-containing (S and T) amino acids, whereas in soluble proteins large hydrophobic and aromatic residues have the highest packing values. The highest packing values for membrane proteins are found in the transmembrane helix-helix interfaces. Glycine and alanine have the highest occurrence among the buried amino acids in membrane proteins, whereas leucine and alanine are the most common buried residue in soluble proteins. These observations are consistent with a shorter axial separation between helices in membrane proteins. The tight helix packing revealed in this analysis contributes to membrane protein stability and likely compensates for the lack of the hydrophobic effect as a driving force for helix-helix association in membranes.

Sleep influences on homeostatic functions: implications for sudden infant death syndrome

The mechanisms underlying the sudden infant death syndrome (SIDS) appear to have origins in the fetal environment resulting in neural damage which later compromises responses to breathing or blood pressure challenges during sleep. The deficits appear to involve alterations in neurotransmitter receptors within regions involved in chemoreception and cardiovascular control. SIDS risk is enhanced by pre- and postnatal nicotine exposure, and possibly by hypoxic experiences. The prone sleeping position plays a significant role in risk, as do head positions that minimize facial escape from enclosed spaces; elevated body temperature may also be a factor. Compensatory mechanisms, including diminished gasping ability, relative failure to arouse to a safer state, or a failure to recruit respiratory efforts to overcome a blood pressure loss have been the object of recent research efforts. The findings suggest that the fatal event involves a neurally-compromised infant, circumstances that challenge vital physiology, most likely during sleep, at a particular developmental period.

A clinical comparison of SIDS and explained sudden infant deaths: how healthy and how normal? CESDI SUDI Research Group. Confidential Inquiry into Stillbirths and Deaths in Infancy study

OBJECTIVES

To compare the clinical characteristics associated with sudden infant death syndrome (SIDS) and explained sudden unexpected deaths in infancy (SUDI).

DESIGN

Three year population based, case control study with parental interviews for each death and four age matched controls.

SETTING

Five regions in England (population, > 17 million; live births, > 470,000).

SUBJECTS

SIDS: 325 infants; explained SUDI: 72 infants; controls: 1,588 infants.

RESULTS

In the univariate analysis, all the clinical features and health markers at birth, after discharge from hospital, during life, and shortly before death, significant among the infants with SIDS were in the same direction among the infants who died of explained SUDI. In the multivariate analysis, at least one apparent life threatening event had been experienced by more of the infants who died than in controls (SIDS: 12% v 3% controls; odds ratio (OR) = 2.55; 95% confidence interval (CI), 1.02 to 6.41; explained SUDI: 15% v 4% controls; OR = 16.81; 95% CI, 2.52 to 112.30). Using a retrospective illness scoring system based on "Baby Check", both index groups showed significant markers of illness in the last 24 hours (SIDS: 22% v 8% controls; OR = 4.17; 95% CI, 1.88 to 9.24; explained SUDI: 49% v 8% controls; OR = 31.20; 95% CI, 6.93 to 140.5).

CONCLUSIONS

The clinical characteristics of SIDS and explained SUDI are similar. Baby Check might help identify seriously ill babies at risk of sudden death, particularly in high risk infants.

Babies sleeping with parents: case-control study of factors influencing the risk of the sudden infant death syndrome. CESDI SUDI research group

OBJECTIVE

To investigate the risks of the sudden infant death syndrome and factors that may contribute to unsafe sleeping environments.

DESIGN

Three year, population based case-control study. Parental interviews were conducted for each sudden infant death and for four controls matched for age, locality, and time of sleep.

SETTING

Five regions in England with a total population of over 17 million people.

SUBJECTS

325 babies who died and 1300 control infants.

RESULTS

In the multivariate analysis infants who shared their parents' bed and were then put back in their own cot had no increased risk (odds ratio 0.67; 95% confidence interval 0.22 to 2.00). There was an increased risk for infants who shared the bed for the whole sleep or were taken to and found in the parental bed (9.78; 4.02 to 23.83), infants who slept in a separate room from their parents (10.49; 4.26 to 25.81), and infants who shared a sofa (48.99; 5.04 to 475.60). The risk associated with being found in the parental bed was not significant for older infants (>14 weeks) or for infants of parents who did not smoke and became non-significant after adjustment for recent maternal alcohol consumption (>2 units), use of duvets (>4 togs), parental tiredness (infant slept </=4 hours for longest sleep in previous 24 hours), and overcrowded housing conditions (>2 people per room of the house).

CONCLUSIONS

There are certain circumstances when bed sharing should be avoided, particularly for infants under four months old. Parents sleeping on a sofa with infants should always be avoided. There is no evidence that bed sharing is hazardous for infants of parents who do not smoke.

Epidemiology of SIDS and explained sudden infant deaths. CESDI SUDI Research Group

OBJECTIVES

To establish whether epidemiologic characteristics for sudden infant death syndrome (SIDS) have changed since the decrease in death rate after the "Back to Sleep" campaign in 1991, and to compare these characteristics with sudden and unexpected deaths in infancy (SUDI) from explained causes.

DESIGN

Three-year, population-based, case-control study. Parental interviews were conducted soon after the death and for 4 controls matched for age and date of interview. All sudden unexpected deaths were included in the study and the cause of death was established by a multidisciplinary panel of the relevant health care professionals taking into account past medical and social history of the mother and infant, the circumstances of death, and a full pediatric postmortem examination. Contributory factors and the final classification of death were made using the Avon clinicopathologic system.

SETTING

Five regions in England, with a total population of >17 million people, took part in the study. The number of live births within these regions during the particular time each region was involved in the study was 473 000.

STUDY PARTICIPANTS

Three hundred twenty-five SIDS infants (91.3% of those available), 72 explained SUDI infants (86.7% of those available), and 1588 matched control infants (100% of total for cases included).

RESULTS

Many of the epidemiologic features that characterize SIDS infants and families have remained the same, despite the recent decrease in SIDS incidence in the United Kingdom. These include the same characteristic age distribution, few deaths in the first few weeks of life or after 6 months, with a peak between 4 and 16 weeks, a higher incidence in males, lower birth weight, shorter gestation, and more neonatal problems at delivery. As in previous studies there was a strong correlation with young maternal age and higher parity and the risk increased for infants of single mothers and for multiple births. A small but significant proportion of index mothers had also experienced a previous stillbirth or infant death. The majority of the SIDS deaths (83%) occurred during the night sleep and there was no particular day of the week on which a significantly higher proportion of deaths occurred. Major epidemiologic features to change since the decrease in SIDS rate include a reduction in the previous high winter peaks of death and a shift of SIDS families to the more deprived social grouping. Just more than one quarter of the SIDS deaths (27%) occurred in the 3 winter months (December through February) in the 3 years of this study. In half of the SIDS families (49%), the lone parent or both parents were unemployed compared with less than a fifth of control families (18%). This difference was not explained by an excess of single mothers in the index group. Many of the significant factors relating to the SIDS infants and families that distinguish them from the normal population did not distinguish between SIDS and explained SUDI. In the univariate analysis many of the epidemiologic characteristics significant among the SIDS group were also identified and in the same direction among the infants dying as SUDI attributable to known causes. The explained deaths were similarly characterized by the same infant, maternal, and social factors, 48% of these families received no waged income. Using logistic regression to make a direct comparison between the two index groups there were only three significant differences between the two groups of deaths: 1) a different age distribution, the age distribution of the explained deaths peaked in the first 2 months and was more uniform thereafter; 2) more congenital anomalies were noted at birth (odds ratio [OR] = 3.14; 95% confidence intervals [CI]: 1.52-6. (ABSTRACT TRUNCATED)

Pacifier use and sudden infant death syndrome: results from the CESDI/SUDI case control study. CESDI SUDI Research Team

OBJECTIVES

To investigate the relation between pacifier use and sudden infant death syndrome (SIDS).

DESIGN

Three year population based, case control study with parental interviews for each death and four age matched controls.

SETTING

Five regions in England (population > 17 million).

SUBJECTS

325 infants who had died from SIDS and 1300 control infants.

RESULTS

Significantly fewer SIDS infants (40%) than controls (51%) used a pacifier for the last/reference sleep (univariate odds ratio (OR), 0.62; 95% confidence interval (CI), 0.46 to 0.83) and the difference increased when controlled for other factors (multivariate OR, 0.41; 95% CI, 0. 22 to 0.77). However, the proportion of infants who had ever used a pacifier for day (66% SIDS v 66% controls) or night sleeps (61% SIDS v 61% controls) was identical. The association of a risk for SIDS infants who routinely used a pacifier but did not do so for the last sleep became non-significant when controlled for socioeconomic status (bivariate OR, 1.39 (0.93 to 2.07)).

CONCLUSIONS

Further epidemiological evidence and physiological studies are needed before pacifier use can be recommended as a measure to reduce the risk of SIDS.

Leptospira interrogans antibodies in feral pigs from New South Wales

The sera of 195 hunter-killed feral pigs (Sus scrofa), collected in New South Wales (Australia) from April to November 1995, were screened against a reference panel of 14 Leptospira interrogans serovars using a microscopic agglutination test (MAT). The panel represented those serovars previously isolated from wild and domestic mammals in mainland Australia. Antileptospiral agglutinins were detected in 20% of the sera tested and included nine L. interrogans serovars. The majority of serological reactors (63%) were to L. interrogans serovar pomona. Sera from 26% of immunoreactors cross reacted with antigens from one or more serovars. No differences were noted in the prevalence of L. interrogans antibodies between the sexes, or between pigs from areas of low and high rainfall. The implications of leptospirosis in feral pigs on the transmission of leptospires to wildlife, livestock, and humans are discussed.

Mouse cytochrome b561: cDNA cloning and expression in rat brain, mouse embryos, and human glioma cell lines

A cDNA encoding cytochrome b561 has been isolated from a mouse brain cDNA library, which predicts a protein of 250 amino acids with a deduced Mr of 27,770. Northern blot analysis of different mouse and rat tissues revealed one major mRNA of 3300 bp, which is abundantly distributed in a number of neuroendocrine tissues. In addition, cytochrome mRNA levels in rat brain sections showed the highest distribution of cytochrome b561 in the hypothalamus, hippocampus, thalamus, and striatum, with a moderate level in the cerebral cortex, and the lowest levels in the olfactory bulb and cerebellum. Because non-neuronal cells in the central nervous system contained peptidyl alpha-amidating monooxygenase (PAM), to which cytochrome b561 donates its electrons, we used RT-PCR to document the coexpression of cytochrome b561 with PAM and dopamine beta-hydroxylase (DBH) in glioblastoma cells. Cytochrome b561 expression was detectable in the 11-day-old mouse embryo, and the level of its mRNA increased tenfold by 15 and 17 days of gestation.

Randomised controlled trial of L-carnitine as a nutritional supplement in preterm infants

AIMS

To evaluate the effect of L-carnitine supplementation (25 mg/kg/d) on the growth and incidence of hypoglycaemia in preterm infants.

METHODS

A double blind, placebo controlled randomised trial, stratified for gestational age, was conducted of 86 preterm infants between 28 and 34 gestational weeks. The median gestational ages in the carnitine group and placebo groups were 30.7 weeks (range 28.0 to 33.6) and 31.4 weeks (range 28.0 to 33.9), respectively. The median birthweights were 1.557 kg (range 0.944 to 2.275) and 1.645 kg (range 0.885 to 2.545), respectively.

RESULTS

Mean plasma free carnitine concentrations were below values for normal term infants in both groups on day 1 (carnitine group 44.8 mumol/l, placebo group 25.5 mumol/l) in the placebo group on day 7 (50.7 mumol/l), but in neither group on days 14 and 28. Total, free, and acylcarnitine concentrations were significantly increased in both urine and blood in the L-carnitine group. There was no significant difference between the placebo and carnitine supplemented groups in growth rate, as assessed by weight, length, skinfold thickness and head circumference measurements, or in the incidence of episodes of hypoglycaemia.

CONCLUSION

The addition of carnitine as a nutritional supplement at a dose of 25 mg/kg/day did not improve growth in our group of preterm infants nor protect them from episodes of hypoglycaemia.

The crystal structure of a hyperthermophilic archaeal TATA-box binding protein

This study analyzes the three-dimensional structure of the TATA-box binding protein (TBP) from the hyperthermophilic archaea Pyrococcus woesei. The crystal structure of P. woesei TBP (PwTBP) was solved at 2.2 A by X-ray diffraction and as expected from sequence homology (36% to 41% identical to eukaryotic TBPs) its overall structure is very similar to eukaryotic TBPs. The thermal unfolding transition temperature of this protein was measured by differential scanning calorimetry to be 101 degrees C, which is more than 40 degrees C higher than that of yeast TBP. Preliminary titration calorimetry data show that the affinity of PwTBP for its DNA target, unlike its eukaryotic counterparts, is enhanced by increasing the temperature and salt concentration. The structure reveals possible explanations for this thermostability and these unusual DNA binding properties. The crystal structure of this hyperthermostable protein was compared to its mesophilic homologs and analyzed for differences in the native structure that may contribute to thermostability. Differences found were: (1) a disulfide bond not found in mesophilic counterparts; (2) an increased number of surface electrostatic interactions; (3) more compact protein packing. The presumed DNA binding surface of PwTBP, like its eukaryotic counterparts, is hydrophobic but the electrostatic profile surrounding the protein is relatively neutral compared to the asymmetric positive potential that surrounds eukaryotic TBPs. The total reliance on a hydrophobic interface with DNA may explain the enhanced affinity of PwTBP for its DNA promoter at higher temperatures and increased salt concentration.

Thermal stress, sleeping position, and the sudden infant death syndrome

We review the evidence than overheating or disordered thermoregulation may be responsible for some cases of the Sudden Infant Death Syndrome (SIDS). Possible mechanisms for an interaction of thermal stress and the prone position are discussed with an emphasis on heat production and loss via the infant head. After the reduction in the prevalence of the prone position following "Back to Sleep" campaigns, and the emergence of cigarette smoking as a key risk factor, the role of disordered thermoregulation continues to be important in many cases of SIDS.

Smoking and the sudden infant death syndrome: results from 1993-5 case-control study for confidential inquiry into stillbirths and deaths in infancy. Confidential Enquiry into Stillbirths and Deaths Regional Coordinators and Researchers

OBJECTIVE

To investigate the effects of exposure to tobacco smoke and of parental consumption of alcohol and illegal drugs as risk factors for the sudden infant death syndrome after a national risk reduction campaign which included advice on prenatal and postnatal avoidance of tobacco smoke.

DESIGN

Two year population based case-control study. Parental interviews were conducted for each infant who died and four controls matched for age and date of interview.

SETTING

Three regions in England with a total population of 17 million people.

SUBJECTS

195 babies who died and 780 matched controls.

RESULTS

More index than control mothers (62.6% v 25.1%) smoked during pregnancy (multivariate odds ratio = 2.10; 95% confidence interval 1.24 to 3.54). Paternal smoking had an additional independent effect when other factors were controlled for (2.50; 1.48 to 4.22). The risk of death rose with increasing postnatal exposure to tobacco smoke, which had an additive effect among those also exposed to maternal smoking during pregnancy (2.93; 1.56 to 5.48). The population attributable risk was over 61%, which implies that the numbers of deaths from the syndrome could be reduced by almost two third if parents did not smoke. Alcohol use was higher among index than control mothers but was strongly correlated with smoking and on multivariate analysis was not found to have any additional independent effect. Illegal drug use was more common among the index parents, and paternal use of illegal drugs remained significant in the multivariate model (4.68; 1.56 to 14.05).

CONCLUSIONS

This study confirms the increased risk of the sudden infant death syndrome associated with maternal smoking during pregnancy and shows evidence that household exposure to tobacco smoke has an independent additive effect. Parental drug misuse has an additional small but significant effect.

Environment of infants during sleep and risk of the sudden infant death syndrome: results of 1993-5 case-control study for confidential inquiry into stillbirths and deaths in infancy. Confidential Enquiry into Stillbirths and Deaths Regional Coordinators and Researchers

OBJECTIVE

To investigate the role of sleeping arrangements as risk factors for the sudden infant death syndrome after a national risk reduction campaign.

DESIGN

Two year population based case-control study. Parental interviews were conducted for each infant who died and for four controls matched for age and date of interview.

SETTING

Three regions in England with a total population of 17 million people.

SUBJECTS

195 babies who died and 780 matched controls.

RESULTS

Prone and side sleeping positions both carried increased risks of death compared with supine when adjusted for maternal age, parity, gestation, birth weight, exposure to smoke, and other relevant factors in the sleeping environment (multivariate odds ratio = 9.00 (95% confidence interval 2.84 to 28.47) and 1.84 (1.02 to 3.31), respectively). The higher incidence of side rather than prone sleeping led to a higher population attributable risk (side 18.4%, prone 14.2%). More of the infants who died were found with bed covers over their heads (21.58; 6.21 to 74.99). The use of a dummy had an apparent protective effect (0.38; 0.21 to 0.70). Bed sharing for the whole night was a significant risk factor for infants whose mothers smoked (9.25; 2.31 to 34.02). No protective effect of breast feeding could be identified on multivariate analysis.

CONCLUSIONS

This study confirms the importance of certain risk factors for the sudden infant death syndrome and identifies others-for example, covers over the head, side sleeping position-which may be amenable to change by educating and informing parents and health care professionals.

Occluded molecular surface: analysis of protein packing

We describe a novel method to calculate the packing interactions in protein structural models. The method calculates the interatomic occluded surface areas for each atom in the protein model. The identification of, and degree of interaction with, neighboring atoms is accomplished by extending surface normals from a dot surface of each atom to the point of intersection with neighboring atoms. The combined occluded and non-occluded surface areas may be normalized for the amino acid composition of the protein providing a single parameter, the normalized protein surface ratio, which is diagnostic for native-like structures. Individual residues in the model which are in infrequent occluded surface environments may be identified. The method provides a means to explicitly describe packing densities and packing environments of individual atoms in a protein model. Finally, the method allows estimation of the complementarity between any interacting molecules, for example a ligand binding to a receptor.

The foot in ballet dancers: the importance of second toe length

Ballet dancers are prone to foot injuries. Our hypothesis was that the length of the second toe in relation to the big toe affected the distribution of stresses on the foot, correlating with calluses, injuries, and pain. Fifty-nine ballet dancers were examined for second toe length with respect to great toe, calluses, and metatarsophalangeal inflammation. Daily foot pain, limitation of work hours because of this, injuries, age, sex, and rank in the company were considered. The dancers' feet had an incidence of shorter, equal, or longer second toes which was comparable to a non-ballet-dancing cohort (N = 60). In female dancers (N = 34), total callus counts and pain scores were significantly lower in the group with shorter second toes versus those with equal or longer second toes. Counts were unrelated to age or rank. Longer second toes were related to hallux rigidus. Limitation of practice hours, ankle sprains, and foot/ankle fractures and sprains were comparable across the groups. The male dancers (N = 25) had significantly fewer calluses than did the women, but had equal pain scores and number of injuries. There were no significant differences among the males in total callus counts, pain scores, limitation of practice hours, or injuries between groups based on toe length, age, or rank. We conclude that there is no significantly more ideal pattern of toe lengths for male ballet dancers, but females with shorter second toes have fewer calluses and less daily foot pain. Those with a longer second toe had a higher incidence of hallux rigidus and correspondingly increased pain scores.

Bottle feeding and the sudden infant death syndrome

OBJECTIVE

To determine whether the risk of the sudden infant death syndrome is increased in bottle fed babies.

DESIGN

Population based case-control study matching for age and time.

SUBJECTS

All babies aged 1 week to 1 year dying of sudden infant death syndrome during November 1987 to April 1989 or February 1990 to June 1991 and two live controls.

SETTING

Avon and north Somerset.

MAIN OUTCOME MEASURES

Breast or bottle feeding, sleeping position, maternal smoking, parental employment, and length of gestation.

RESULTS

Compared with being fully breast fed, the crude odds ratio for sudden infant death in fully bottle fed babies was 3.1 and for mixed breast and bottle fed babies 1.5. These odds ratios fell to 1.8 (95% confidence interval 0.7 to 4.8) and 1.2 (0.5 to 2.7) respectively after maternal smoking, parental employment, preterm gestation, and sleeping position had been adjusted for. Sleeping position partly masked the effect of being bottle fed on sudden infant death as breast fed babies were more likely to have slept prone than bottle fed babies.

CONCLUSIONS

Bottle feeding is not a significant independent risk factor for the sudden infant death syndrome. Patterns of maternal smoking, preterm gestation, and parental employment status account for most of the apparent association with bottle feeding.

Phenylalanine kinetics in sick preterm neonates with respiratory distress syndrome

The cause of hyperphenylalaninemia in sick preterm infants has yet to be determined; one reason may be reduced tolerance to phenylalanine as a consequence of immaturity of phenylalanine hydroxylase. Phenylalanine metabolism was studied in vivo in 23 ventilated preterm infants of gestational age 23 to 36 wk within the first 6 d of life using a continuous i.v. infusion of the stable isotope-labeled amino acids [2H5]phenylalanine, [2H4]tyrosine, and [2H2]tyrosine. Phenylalanine hydroxylation was calculated from two different methods. In the first method, used in all 23 infants receiving glucose and in seven of these infants who subsequently received parenteral nutrition, phenylalanine hydroxylation was calculated from the plasma enrichments of [2H5]phenylalanine and [2H4]tyrosine and from the molar ratio of tyrosine to phenylalanine in mammalian tissue protein. In this instance, the mean hydroxylation was 16.0 (SD 10.9) and 48.4 (SD 14.9) mumol/kg/h, which was 17.3% (SD 8.4%) and 33.2% (SD 9.8% of the total phenylalanine flux for infants receiving glucose and parenteral nutrition, respectively. Additionally, in six infants receiving glucose, hydroxylation was calculated from the measured phenylalanine (2H5), independent tyrosine (2H2) fluxes, and the plasma enrichments of (2H5) phenylalanine and its hydroxylation product [2H4]tyrosine. In this case, hydroxylation was 20.5 (SD 13.0) mumol/kg/h, which represented 22.3% (SD 9.8%) of the phenylalanine flux. In the same six infants, phenylalanine hydroxylation derived using the first method was 22.2 (SD 13.1) mumol/kg/h, 23.6% (SD 9.9%) of the total phenylalanine flux.(ABSTRACT TRUNCATED AT 250 WORDS)

The anaphylaxis hypothesis of sudden infant death syndrome (SIDS): mast cell degranulation in cot death revealed by elevated concentrations of tryptase in serum

A series of cases of sudden unexpected post-neonatal deaths from two centres in the UK have been investigated for evidence of mast cell activation using the biochemical markers tryptase and 9 alpha,11 beta-PGF2. Tryptase was selected as a possible marker because it is a component of mast cell secretory granules and, unlike histamine, it is not released from basophils. The prostaglandin 9 alpha,11 beta-PGF2 is an initial and pharmacologically active metabolite of PGD2, the major mast cell-derived cyclooxygenase product. This prostaglandin was chosen to serve as a marker of newly generated mediator release. In the study, unexplained infant deaths were associated with a higher concentration of tryptase in serum compared with cases of unexpected, but subsequently explained death. However, 9 alpha,11 beta-PGF2 was found to be an unsuitable post mortem marker in this situation. These results provide direct evidence that mast cell degranulation, possibly as a result of anaphylaxis, may be occurring around the time of death in some cases of cot death.

Human cytochrome b561: a revised hypothesis for conformation in membranes which reconciles sequence and functional information

Cytochrome b561 is a major transmembrane protein of catecholamine and neuropeptide secretory vesicles. In this report, we describe the cloning and properties of a full-length cDNA encoding human neuroendocrine cytochrome b561 from a human caudate cDNA library and a human peripheral blood genomic library. The human cDNA contains two major transcription start sites and only one translation start site that codes for an apocytochrome b561, which is 22 amino acid residues smaller than the previously deduced amino acid sequence from bovine cDNA. This smaller version of cytochrome b561 may contain only five transmembrane segments rather than the previously proposed six segments. The new model is in agreement with our previous results on transmembrane topology of the gene product. Northern-blot analysis shows an expanded tissue distribution of cytochrome mRNA expression where previous immunological assays were negative. These results support the hypothesis that cytochrome b561 is a marker for peptidergic and adrenergic tissues.

SIDS: risk reduction measures

Increasing public awareness of the prone sleeping position, maternal smoking and overheating as potentially avoidable risk factors for the sudden infant death syndrome (SIDS) has been accompanied by a dramatic reduction in mortality. The results of two population based studies of SIDS in Avon are compared; the first one occurred before these risk factors were widely known and during the second study there was a gradual increase in publicity. Between the studies the prevalence of prone sleeping in the control populations fell significantly from 60% to 28% and almost all of the reduction in SIDS mortality (3.5 to 1.7 per thousand live births) could be attributed to this change. Other changes were also found: the seasonal pattern of incidence was lost, the proportion of expreterm babies increased and the male predominance was accentuated. The relative importance of smoking and bottle feeding appeared to increase whereas the odds ratios for heavy wrapping and overnight heating were no longer significantly elevated. Small numbers limit the significance of these individual variations but demonstrate that changes are occurring. Local and national public health campaigns have been launched in the UK and abroad to encourage infant care practices that reduce the risk of SIDS. Monitoring the effectiveness of these campaigns is important and may allow new risk factors to be identified which could in turn be targeted in future preventative campaigns. Significant reductions in mortality have followed these initial campaigns but in order to maintain them the message must be regularly renewed using an appropriate approach and effective channels of communication to target high risk families within the community.

Understanding and preventing sudden infant death syndrome

Over the past few years a number of factors related to child care practices and environment (eg, sleeping position, thermal environment, and parental smoking) have been recognized as potentially important in the risk of sudden infant death syndrome (SIDS). Detailed studies of these factors have led to a greater understanding of normal development and of ways of possibly reducing the risk of SIDS. Campaigns to reduce the risk of SIDS have now been undertaken in several countries; in the United Kingdom, New Zealand, and Holland there have been marked falls in SIDS rates after such interventions. Recent physiologic studies of thermal balance, the role of infection, and the possibility of carbon dioxide rebreathing have shed considerable light on possible mechanisms by which these factors may exert their effects.

Thermal balance and metabolic rate during upper respiratory tract infection in infants

Sequential recordings were made in the first five months after birth of metabolic rate, environmental temperature, and body temperature during sleep at home in 17 infants, each with an older sibling. Further recordings were made whenever an older sibling developed an upper respiratory tract infection (URTI), again four to six days later, and again two weeks later, aiming to achieve recordings before, during, and after an URTI in the infant. The temperature of the room and wrapping of the infant were determined according to their usual practice by the parents. Parents added appropriate wrapping to achieve thermal neutrality based on our calculated values and the measured oxygen consumption. In five of the six infants who developed an URTI in the first three months after birth there was no change or a decrease in metabolic rate at the time of the infection; for infants older than 3 months the metabolic rate increased in three of the five episodes recorded. Peripheral skin temperature decreased at the time of URTI at all ages, though in the older infants it usually increased in parallel with rectal temperature during the latter part of the night, when pyrexia was most common. Infants thus respond to URTI by heat conservation. In the younger infants the lower metabolic rate and the further decrease in this rate with URTI means that fever is rare, and their temperature may decrease on infection. In the older infants the increase in metabolic rate (from an already higher baseline) may result in fever. These differences may contribute to the increased vulnerability of the older infants to heat stress, particularly at the time of acute viral infections.

How much wrapping do babies need at night?

In a longitudinal, population based study, overnight temperature recordings were made in the bedrooms of 152 babies aged 3-18 weeks and the insulation provided by their bedclothing was assessed. Outdoor temperatures for the study nights were also available. Parents applied more insulation on colder nights with lower bedroom temperatures than on warmer nights (mean 8.5 tog at 15 degrees C minimum bedroom temperature falling to 4.0 tog at 25 degrees C). For a particular temperature they also applied 2 tog more insulation in winter than in summer. The amounts of bedclothing used in the home were compared with insulation levels predicted to achieve thermo-neutrality over a similar range of environmental temperature from heat balance studies in young infants. They corresponded closely. The average amount of bedclothing chosen for babies in Avon allows them to remain in thermoneutral conditions throughout the night. These values are proposed as broad guidelines for the thermal care of young babies at night.

Interactions between thermoregulation and the control of respiration in infants: possible relationship to sudden infant death

In summary, there is evidence that developmental changes in respiratory control and in thermoregulation have effects upon each other. Theoretically, such effects could give rise to failure of the respiratory system and there is some circumstantial evidence to support the concept that on occasions such interactions may be of importance in sudden unexpected death in infancy. Future research in this area should focus on the nature of the interactions between thermoregulation and respiration, and on the effects of infection and infection-related mediators on those interactions.