Action potential-dependent regulation of gene expression: temporal specificity in ca2+, cAMP-responsive element binding proteins, and mitogen-activated protein kinase signaling

Specific patterns of neural impulses regulate genes controlling nervous system development and plasticity, but it is not known how intracellular signaling cascades and transcriptional activation mechanisms can regulate specific genes in response to specific patterns of action potentials. Studies using electrical stimulation of mouse dorsal root ganglion neurons in culture show that the temporal dynamics of intracellular signaling pathways are an important factor. Expression of c-fos varied inversely with the interval between repeated bursts of action potentials. Transcription was not dependent on a large or sustained increase in intracellular Ca2+, and high Ca2+ levels separated by long interburst intervals (5 min) produced minimal increases in c-fos expression. Levels of the transcription factor cAMP-responsive element binding protein (CREB), phosphorylated at Ser-133, increased rapidly in response to brief action potential stimulation but remained at high levels several minutes after an action potential burst. These kinetics limited the fidelity with which P-CREB could follow different patterns of action potentials, and P-CREB levels were not well correlated with c-fos expression. The extracellular-regulated kinase (ERK) mitogen-activated protein kinases (MAPK) also were stimulated by action potentials of appropriate temporal patterns. Bursts of action potentials separated by long intervals (5 min) did not activate MAPK effectively, but they did increase CREB phosphorylation. This was a consequence of the more rapid dephosphorylation of MAPK in comparison to CREB. High expression of c-fos was dependent on the combined activation of the MAPK pathway and phosphorylation of CREB. These observations show that temporal features of action potentials (and associated Ca2+ transients) regulate expression of neuronal genes by activating specific intracellular signaling pathways with appropriate temporal dynamics.

The efficacy of sucrose for relieving procedural pain in neonates--a systematic review and meta-analysis

The objective was to determine the efficacy and optimal dose of sucrose for relieving procedural pain in neonates. Data were obtained using MEDLINE, EMBASE, Reference Update and personal files and assessed for quality of the methods. Data from all randomized controlled trials where term and preterm neonates received a heelstick or venipuncture were examined for the efficacy of different sucrose doses (0.18 g, 0.24 g, 0.48 g or 0.50 g, 1.0 g) and water (placebo). The primary outcome was the proportion of time crying during 3 min after the painful stimulus. Data were combined across studies using a random effects model, adapted for use with single groups, producing a point estimate and 95% confidence interval (CI). Thirteen trials were identified; eight were rejected as data were inappropriate, non-extractable, or the primary outcome was not measured. Five studies provided data on 271 infants. The proportion of time crying did not differ between 0.18 g of sucrose and water (p > 0.05) but was significantly lower in all other sucrose groups. There were no differences in proportion of time crying between term and preterm neonates. Sucrose reduced the proportion of time crying during painful procedures in neonates. The 0.18 g dose of sucrose was ineffective. Doses of 0.24 g (2 ml of 12% sucrose solution) were most effective. A dose of 0.50 g provided no additional benefit.

Comparing nursing costs for preterm infants receiving conventional vs. developmental care

The incremental costs incurred by VLBW (less than 1,500 grams) infants during the first year of life accounted for one-third of the $11.4 billion spent in the U.S. on health care. Developmental care for VLBW infants focuses on light and noise management, coordination of interventions to minimize sleep interruptions and positioning/bundling the infant to prevent disorganizaiton and promote self-regulation. When compared to 60 VLBW infants receiving conventional NICU care, improved physiologic stability measures and fewer days in the NICU were recorded for the 60 VLBW infants cared for by nurses and trained developmental care specialists. Because the move from the NICU to the transitional unit occurred earlier for the developmental group of VLBW infants, and their nursing intensity needs were lower, the average cost savings achieved for this group was $4,340 per infant during the first 35 days of life or less if discharged.

Efficacy and safety of lidocaine-prilocaine cream for pain during circumcision

BACKGROUND

Neonatal circumcision is a painful surgical procedure often performed without analgesia. We assessed the efficacy and safety of 5 percent lidocaine-prilocaine cream (Emla) in neonates undergoing circumcision.

METHODS

We carried out a double-blind, randomized, controlled trial in 68 full-term male neonates: 38 were assigned to receive lidocaine-prilocaine cream, and 30 to receive placebo. One gram of lidocaine-prilocaine or placebo cream was applied to the penis under an occlusive dressing for 60 to 80 minutes before circumcision. Behavioral (facial activity and time spent crying) and physiologic (heart rate and blood pressure) responses were recorded during the procedure. Blood samples were obtained at various times after drug application for measurements of methemoglobin and plasma lidocaine, prilocaine, and o-toluidine (a metabolite of prilocaine).

RESULTS

A total of 68 and 59 neonates were included in the safety and efficacy analyses, respectively. Demographic characteristics such as gestational age and birth weight did not differ between the lidocaine-prilocaine and placebo groups. During circumcision, the neonates in the lidocaine-prilocaine group had less facial activity (P= 0.01), spent less time crying (P<0.001), and had smaller increases in heart rate (P=0.007) than the neonates in the placebo group. Facial-activity scores were 12 to 49 percent lower during various steps of the procedure in the lidocaine-prilocaine group. As compared with neonates in the placebo group, infants in the lidocaine-prilocaine group cried less than half as much and had heart-rate increases of 10 beats per minute less. Blood methemoglobin concentrations (expressed as a percentage of the hemoglobin concentration) were similar (1.3 percent) in both groups. Lidocaine and prilocaine were detected in plasma in 23 (61 percent) and 21 (55 percent) of the infants treated with lidocaine-prilocaine cream, respectively.

CONCLUSIONS

Lidocaine-prilocaine cream is efficacious and safe for the prevention of pain from circumcision in neonates.

Pain management in newborns: how far have we progressed in research and practice?

Compelling research supports the newborn infant's capacity for pain. Yet, pain is frequently underestimated and undertreated. This is a result of limited understanding of pain pathway development, immediate and long-term consequences, measurement tools and approaches, and safety and efficacy of pain-relieving interventions. This paper reviews recent research in relation to management of pain in the newborn, and presents implications for practice and future research.

Developmental changes in response to heelstick in preterm infants: a prospective cohort study

Twenty-eight preterm infants of 28 weeks gestational age were observed four times over eight weeks in order to determine changes in their pain response. Both routine and sham heelstick procedures were used. Physiological (heart rate and oxygen saturations) and behavioural parameters (three upper facial actions) were used as outcomes. The responses to real heelstick were significantly greater than to sham heelstick for heart rate and all facial actions except one at 28 weeks gestational age, but not for oxygen saturation. The magnitude of response to both real and sham heelstick increased over time. Thus, the older the infant, the more robust and recognisable the response. Since even the youngest infants showed a differential response to pain, professionals caring for such infants need to be able to recognize their more subtle pain responses.

Management of painful procedures in the newborn

Management of painful procedures in the neonate is less than optimal. Although evidence exists to support the infant's capacity to feel pain at birth, health professionals do not prescribe or administer adequate analgesia. This is largely because of the lack of published data on the safety and efficacy of pharmacologic interventions and lack of sufficient understanding of the benefits of nonpharmacologic measures. In this review, recent research on the safety and efficacy of pharmacologic and nonpharmacologic interventions for managing painful procedures in the neonate is summarized.

Premature Infant Pain Profile: development and initial validation

OBJECTIVE

Inadequate assessment of pain in premature infants is a persistent clinical problem. The objective of this research was to develop and validate a measure for assessing pain in premature infants that could be used by both clinicians and researchers.

DESIGN

The Premature Infant Pain Profile (PIPP) was developed and validated using a prospective and retrospective design. Indicators of pain were identified from clinical experts and the literature. Indicators were retrospectively tested using four existing data sets.

PATIENTS AND SETTINGS

Infants of varying gestational ages undergoing different painful procedures from three different settings were utilized to develop and validate the measure.

METHODS AND RESULTS

The largest data set (n = 124) was used to develop the PIPP. The development process included determining the factor structure of the data, developing indicators and indicator scales and establishing internal consistency. The remaining three data sets were utilized to establish beginning construct validity.

CONCLUSIONS

The PIPP is a newly developed pain assessment measure for premature infants with beginning content and construct validity. The practicality and feasibility for using the PIPP in clinical practice will be determined in prospective research in the clinical setting.

Developmental versus conventional care: a comparison of clinical outcomes for very low birth weight infants

The purpose of this research was to describe the clinical profile of very low birth weight (VLBW) infants receiving conventional versus developmental care during their hospitalization and to determine the appropriateness of developmental-care interventions. A phase-lag study with 124 preterm infants indicated that although there were no significant differences in individual clinical outcomes, developmental care had a significant effect on the physiologic stability of the infant over time. Developmental interventions were used for all infants receiving the developmental-care intervention, with varying frequency.

Outcomes management in neonatal nursing clinical practice

One approach for evaluating the quality and cost of patient care is through outcomes management. Outcomes management in a neonatal environment will be described within a structure-process-outcome framework. Outcomes will be presented from three perspectives: administrative, economic and clinical. The relevance and implications of outcomes management will be discussed.

Safety of lidocaine-prilocaine cream in the treatment of preterm neonates

The safety of lidocaine-prilocaine cream (EMLA) was evaluated in an open trial in 30 preterm neonates (mean gestational age, 32.8 weeks; birth weight, 1911 gm); 0.5 gm was applied to the heel for 1 hour. Mean baseline and follow-up (4, 8, or 12 hours after EMLA application) methemoglobin levels were not different, ranging from 1.15% to 1.45%, and from 1.13% to 1.49%, respectively.

Regulated expression of the neural cell adhesion molecule L1 by specific patterns of neural impulses

Development of the mammalian nervous system is regulated by neural impulse activity, but the molecular mechanisms are not well understood. If cell recognition molecules [for example, L1 and the neural cell adhesion molecule (NCAM)] were influenced by specific patterns of impulse activity, cell-cell interactions controlling nervous system structure could be regulated by nervous system function at critical stages of development. Low-frequency electrical pulses delivered to mouse sensory neurons in culture (0.1 hertz for 5 days) down-regulated expression of L1 messenger RNA and protein (but not NCAM). Fasciculation of neurites, adhesion of neuroblastoma cells, and the number of Schwann cells on neurites was reduced after 0.1-hertz stimulation, but higher frequencies or stimulation after synaptogenesis were without effect.

Incest revisited: delayed post-traumatic stress disorder in mothers following the sexual abuse of their children

The case histories of four women who developed symptoms of post-traumatic stress disorder following the disclosure of the sexual abuse of their daughters are presented. These individuals also exhibited comorbid symptoms of depression and personality disorders. Awareness of the sexual abuse of their daughters catalyzed a reliving of their own childhood victimization. The psychodynamics operating in these cases, as well as treatment strategies are also presented. A brief follow-up of three of the four cases is included.

Effect of gender, birth weight and gestational age on serum 17-hydroxyprogesterone concentration and distribution among neonates in Saudi Arabia

Blood samples from 813 newborns were spotted on to filter paper and the 17-hydroxyprogesterone concentration was measured using the Delfia (R) fluorometric immunoassay. The median, mean, and standard deviation (SD) for the total population were 20, 21 and (11) nmol/L respectively. Males had significantly higher levels than females with median, mean and (SD) of 22, 22 and (12) nmol/L. Similarly, low birth weight babies were found to have significantly higher levels than normal birth weight babies with median, mean and (SD) of 21, 24 (12) nmol/L. Preterm babies were also found to have significantly higher levels than full term babies, with median, mean and (SD) of 25, 29 (16) nmol/L. As experienced elsewhere, those factors should be taken into consideration when considering a cut-off point in any neonatal screening program for congenital adrenal hyperplasia.

A revised measure of acute pain in infants

Acute pain in infants is not assessed or managed optimally. The objectives of the study were (a) to adapt a behavioral pain assessment measure (Children's Hospital of Eastern Ontario Pain Scale, CHEOPS) for use with infants, and (b) to establish the reliability and validity of the measure in a study of infants undergoing immunization. Ninety-six healthy 4- to 6-month-old infants were randomized to receive either the local anesthetic cream Eutectic Mixture of Local Anesthetics (EMLA) (N = 49), or a placebo (N = 47) prior to immunization. The infant's behavioral response was videotaped immediately before and following the immunization. Postprocedural pain scores were assessed from the videotape and were significantly lower in infants who received EMLA (P = 0.01). Pain scores were also significantly correlated with visual analogue scale (VAS) scores assessed during vaccination. Five independent raters also independently rated ten infants to determine interrater reliability. Agreement between raters' scores was high (intraclass correlation coefficient, 0.95). Results from this study suggest that this measure has beginning construct and concurrent validity and interrater reliability when used in a research study. Further testing of the measure in the clinical setting is required.

Enhanced retention of asbestos fibers in the airways of human smokers

To determine whether cigarette smoke increases the pulmonary retention of asbestos, we compared the asbestos-fiber burden in the airway mucosa of six cigarette smokers who had received heavy occupational asbestos exposure with that in a group of six subjects with similar exposure who were never smokers. The groups were matched in terms of age, sex, years of exposure, and mean parenchymal amosite burden. We found that the concentration of amosite in airway mucosa was significantly elevated (by approximately sixfold) in smokers (p < 0.02). Chrysotile parenchymal burdens were statistically similar in both groups, but the chrysotile airway burden was again higher (by approximately 50-fold) in smokers (p < 0.006). There were no differences in airway or parenchymal tremolite burdens between the two groups. Fibers of all three types of asbestos recovered from the airway mucosa or parenchyma of smokers were shorter than fibers recovered from nonsmokers, an observation in accord with experimental data suggesting that cigarette smoke leads to retention of shorter fibers. These findings indicate that cigarette smoking causes enhanced accumulation of both amosite and chrysotile in the airway mucosa. This process may play a role in potentiating the pathologic effects of asbestos.

Indwelling versus intermittent feeding tubes in premature neonates

OBJECTIVE

To determine the effect of indwelling versus intermittent feeding tube placement on weight gain, apnea, and bradycardia in premature neonates.

DESIGN

Eligible subjects were assigned randomly to either feeding tube method. Each subject was followed for 6 days.

SETTING

The study was conducted in a secondary level neonatal intensive-care unit (NICU), a tertiary level NICU in a perinatal center, and a tertiary level NICU in a referral center.

PATIENTS/PARTICIPANTS

Neonates who were 24-34 weeks gestational age, developmentally appropriate for gestational age, medically stable, on full enteral feedings through an orogastric or a nasogastric tube, and not fluid restricted. Ninety-three neonates were enrolled--49 indwelling group and 44 in the intermittent group. Nine neonates did not complete the study.

INTERVENTIONS

Nasogastric indwelling feeding tubes were placed and left in site for up to 3 days. Orogastric intermittent feeding tubes were placed for each feeding and removed at completion of the feeding.

MAIN OUTCOME MEASURES

Weight gain, apnea, and bradycardia.

RESULTS

Members of both groups had similar demographic characteristics, clinical problems, and nutritional intake. No statistical differences were found between the two groups in weight gain or episodes of apnea and bradycardia.

CONCLUSIONS

There were no statistically or clinically significant differences between the two groups. The intermittent method of feeding is more expensive. Because no clinical differences were found, the type of tube placement chosen for feeding the premature infant may be based on economics.

Effect of neonatal circumcision on pain responses during vaccination in boys

Using data from one of our randomised trials, we investigated post-hoc whether male neonatal circumcision is associated with a greater pain response to routine vaccination at 4 or 6 months. Pain response during routine vaccination with diphtheria-pertussis-tetanus (DPT) alone or DPT followed by Haemophilus influenzae type b conjugate (HIB) was scored blind. 42 boys received DPT and 18 also received HIB. After DPT, median visual analogue scores by an observer were higher in the circumcised group (40 vs 26 mm, p = 0.03). After HIB, circumcised infants had higher behavioural pain scores (8 vs 6, p = 0.01) and cried longer (53 vs 19 s, p = 0.02). Thus neonatal circumcision may affect pain response several months after the event.

Alcohol disorders among patients with burns: crisis and opportunity

A burn injury so severe that inpatient treatment is necessary is a crisis in any patient's life. For patients who also suffer from an alcohol use disorder, hospitalization may offer a unique opportunity to facilitate entry into appropriate treatment. In this study, 442 hospitalized patients with burns were evaluated, and 50 (11%) were diagnosed with an alcohol use disorder by DSM-III-R criteria. All but one of the injuries were deemed preventable. The average length of stay in hospital was 9 days longer for the alcohol group compared with the average stay in the burn center, resulting in additional costs of $337,500. Referral for treatment of the underlying alcohol disorder was recommended for fewer than half the patients. Thus, although the patients with alcohol use disorders had lengthy hospitalizations and were in circumstances that might permit the characteristic denial of alcoholism to be relinquished, the treatment team usually did not capitalize on this opportunity.

Social support: conceptual and methodological issues for research in mental health nursing

The concept of social support has been the focus of growing multidisciplinary interest over the past two decades. Nurses are interested in the role that social support plays in promoting mental health. As empirical research on social support has been addressed with more scientific rigor, many conceptual and measurement issues have emerged. The purpose of this paper is to review the predominant conceptual and measurement issues in the study of social support in mental health nursing. Lack of consensus on conceptual clarity and weakness of measurement of the concept of social support are discussed in relation to the two bodies of literature. Directions for the development of nursing knowledge and methodologic approaches for future nursing research on social support and mental health are proposed.

Posttraumatic stress disorder in patients with burns

Among 39 patients with burns evaluated a mean of 12 months after hospital discharge, 38% met DSM-III-R criteria for post-traumatic stress disorder (PTSD) for at least 1 month. With proposed DSM-IV criteria, 43% met criteria for past or current PTSD. Analysis of specific symptom clusters of PTSD revealed that 74% of patients had been affected by a reexperience symptom for at least 1 month, but only 30% were currently experiencing flashbacks. No correlation was found between several clinical correlates (TBSA, length of hospitalization, and age) and development of PTSD. There was no correlation between presence of a DSM-III-R psychiatric diagnosis at the time of hospitalization and later development of PTSD and no correlation between whether or not a psychiatric diagnosis emerged during hospitalization and later development of PTSD. Finally, patients who had injuries that they could not prevent were no more likely to experience PTSD.

Validating a compendium of goals and objectives for educating CNS students in ambulatory care

In fall 1990, the Department of Veterans Affairs launched a Pilot Ambulatory Care and Education program that has as its major goal the shift from a traditional inpatient specialty-based focus of patient care and health professional education to a more forward-looking outpatient generalist-based focus of care and education. The generalist and specialist focus of the CNS role has been introduced in this innovative ambulatory care program. Formal and informal educational opportunities for interdisciplinary team members and students abound. This article describes the development and validation of a compendium of goals and objectives for educating CNS students in ambulatory care.

The effect of the sight of blood and use of decorative adhesive bandages on pain intensity ratings by preschool children

A total of 70 children between the ages of 3 and 6 years participated in two studies that tested the effect of (a) the sight of blood and (b) the application of a decorated adhesive bandage on pain intensity ratings following a fingerstick. In both studies, children were randomly assigned to one of four groups. These groups allowed for the combinations of testing blood or no blood and the application of a decorated adhesive bandage or plain adhesive bandage. The Oucher (Beyer, 1984) and the Poker Chip Tool (Hester, 1979) were used as self-report measures of pain intensity at the time of the fingerstick and immediately after the application of the adhesive bandage. The pilot study recruited 20 children from two day care centers and subjected them to sham fingersticks. Results indicated that there were no differences across the groups in pain intensity ratings. However, there was a trend for the sight of blood to increase the child's pain intensity rating. Age was a significant covariate across all groups, with younger children reporting higher levels of pain intensity. The second study took place in a pediatric test center of a metropolitan children's hospital. Fifty outpatient children who were receiving fingersticks for preoperative or diagnostic testing were enrolled. Results indicated that there were no differences across groups, and age was only significant on the Poker Chip Tool. These results suggest that simple interventions and distractions are not sufficient to decrease perceived pain intensity ratings in young children.