Estimating inhalation bioavailability for peptides and proteins 1 to 10 kDa in size.

Inhalation is a critical route for occupational exposure. To protect workers from adverse effects, health-based exposure limits (HBELs) are derived using chemical-specific information including inhalation bioavailability. Inhalation bioavailability of large proteins is well studied and generally accepted to be 1% or less. However, the inhalation bioavailability of peptides and proteins 1-10 kDa in size is not well defined. The goal of this study was to expand upon previous analyses and evaluate the inhalation bioavailability of small peptides. Inhalation bioavailability data for 72 peptides and protein samples ranging from 1.1 to 10.9 kDa in size were evaluated. The median inhalation bioavailability was 20%, which is in agreement with previously published analyses. Inhalation bioavailabilities for the vast majority were below 50%. Interestingly, species, peptide size, and peptide identity did not correlate with inhalation bioavailability. Other factors including inhalation dosimetry, peptide degradation, and chemical characteristics also decrease the amount of peptide available for absorption. Together, the median bioavailability of 20% is likely an appropriate estimate of systemic exposure and is sufficiently protective in most cases for the purposes of occupational exposure safety. Thus, in the absence of peptide-specific data or concerns, an inhalation bioavailability default of 20% is recommended for 1-10 kDa peptide and proteins.

Trajectory of Pain, Functional Limitation, and Parental Coping Resources Following Pediatric Short-stay Surgery: Factors Impacting Rate of Recovery.

OBJECTIVES: Although there are many benefits of short-stay hospital admissions for high volume, pediatric surgical procedures, this model of care places greater responsibility on parents for the management of children's pain. This study aimed to document the trajectory of child pain outcomes and a range of parent-reported functional outcomes following discharge from a short-stay surgical admission. Moreover, we aimed to document the trajectory of parental perceived personal coping resources. Second, we assessed whether parental dispositional factors, assessed before hospital discharge, predicted the child's pain intensity and parent-reported functional recovery. METHODS: Participants included children (aged 4 to 14 y) admitted for a short-stay tonsillectomy or appendectomy, and their parents. Parents completed a questionnaire before discharge from hospital. Demographic and surgical information was recorded from medical records. Following discharge, daily assessments of pain and functioning were carried out over a 10-day period using iPods or mobile phones. Predischarge and postdischarge data were obtained for 55 child and parent dyads. RESULTS: Pain intensity scores returned to low levels (2/10 or less) by day 5 for appendectomy and day 10 for tonsillectomy. Parents' perceived personal coping resources increased more slowly following tonsillectomy than appendectomy. Controlling for time since surgery and parental coping resources, parental pain-related catastrophizing was a significant predictor of child pain and functional recovery. DISCUSSION: Short-stay surgery results in parents facing considerable burden in managing their child's pain and functional impairment over a 10-day period. The potential value of screening for parental pain-related catastrophizing before discharge from hospital warrants further consideration and may enable identification of children likely to experience poorer recovery.

Reported light in the sleep environment: enhancement of the sleep diary.

BACKGROUND: Light is the primary synchronizing cue for the circadian timing system, capable of exerting robust physiological effects, even with very dim and/or brief photic exposure. Mammals, including humans, are particularly susceptible to light at night. As such, measures of light in the sleeping environment are critical for evaluating sleep health. Sleep diaries provide inexpensive measures of sleep, but do not typically include light information. METHODS: Four questions probing visual perception of light in the bedtime and waking environments were added to the Consensus Sleep Diary for Morning administration. As part of a lighting intervention study, 18 hospital Labor and Delivery Department personnel completed the sleep diary for 1 week in each of two experimental conditions while wearing Actiwatch devices equipped with photosensors. Diary responses were evaluated against photosensor values from the beginning and end of each rest interval (n=194 rest intervals), as well as against sleep measures, utilizing linear mixed models. RESULTS: Responses to light questions were related to actual light measures at bedtime, controlling for shift type and experimental condition. In addition, subjective light information at bedtime and waking was related to both objective and subjective sleep parameters, with data generally indicating poorer sleep with light in the sleeping environment. CONCLUSION: Questions addressing perception of light in the sleeping environment may provide a crude yet affordable metric of relative photic intensity. Further, as responses relate to sleep outcomes, subjective light information may yield valuable insights regarding mechanisms and outcomes of clinical significance in sleep and circadian research.