Prevalence of dietitian burnout.

BACKGROUND: Burnout is the result of unmanaged stress that has been shown to affect those working in the healthcare professions. Although much research has been conducted on burnout among nurses, physicians and other health professionals, there is limited documentation on the phenomenon among dietitians. The purpose of this study was to establish the prevalence of burnout among dietitians in Ontario, Canada, determine the demographic variables associated with burnout, and compare these results with burnout data for other healthcare professionals. METHODS: The Maslach Burnout Inventory-Human Services Survey and a demographic questionnaire were emailed to registered dietitians. RESULTS: The dietitians surveyed experienced a moderate amount of emotional exhaustion (mean = 19.96), a low level of depersonalisation (mean = 4.31) and a moderate sense of personal accomplishment (mean = 38.61). Statistically significant relationships were found between years as a dietitian and personal accomplishment (r = 0.16; P = 0.05), age and personal accomplishment (r = 0.15; P = 0.01), hours worked per week and emotional exhaustion (r = 0.17; P = 0.01) and hours worked per week and depersonalisation (r = 0.14; P = 0.01). There were no significant differences in mean burnout scores across the five areas of practice. Over 57% of dietitians had scores indicative of moderate to high levels of burnout overall. CONCLUSIONS: Although dietitians have lower levels of burnout compared to other healthcare professionals, moderate levels of emotional exhaustion and only moderate levels of personal accomplishment remain workplace issues for this professional group.

Fetal homologue of infant crying.

Four behavioural states are recognised in the human fetus and are comparable to those of the neonate: 1F (quiet sleep), 2F (active state), 3F (quiet awake), and 4F (active awake). State 5, or crying, is not considered to have a fetal correlate. In a study assessing the effects of exposure to tobacco and cocaine during pregnancy on fetal response and habituation to vibroacoustic stimulation, what appears to be the fetal homologue of crying was observed. These behaviours were seen on ultrasound, and have been captured on video recordings and include: an initial exhalation movement associated with mouth opening and tongue depression, followed by a series of three augmented breaths, the last breath ending in an inspiratory pause followed by an expiration and settling. This is the first report/video documenting these behaviours and suggests the possibility of a state 5F.

Synaptogenesis in the brachial and lumbosacral enlargements of the spinal cord in the postnatal opossum, Monodelphis domestica.

Synaptic proteins were localized in light microscopy on sections of the brachial and lumbosacral enlargements of the spinal cord of postnatal opossums, Monodelphis domestica, to determine whether their expression correlates with the development of major motor pathways and simple motor behaviors. The tissues were fixed, cryoprotected, frozen, cut in 15-micrometer sections, and processed immunohistochemically using antibodies against synaptophysin, synaptotagmin-I, or SNAP-25. Immunolabeling was observed in the presumptive white matter before the presumptive gray matter, suggesting that the proteins are evidenced in growing axons before the onset of synaptogenesis, and it was observed in presumed propriospinal axons before most presumed descending axons of supraspinal origin. In the newborn opossum, the immunolabeling was scant in the gray matter and was limited to the periphery of the ventral horn, and indeed few synapses were seen in electron microscopy in nonexperimental material. Labeling increased in intensity and spread throughout the gray matter until 5-7 weeks, when it was no longer found in the white matter and resembled the adult pattern of labeling. Considering the location and relative intensity of the immunolabeling for the three proteins over time in the two enlargements, synaptogenesis occurs according to three general gradients: rostrocaudal, ventrodorsal, and lateromedial. These gradients match those of spinal cord and limb development, and of the growth of descending axons into the cord. Synaptogenesis is most intense when the spinal sensorimotor reflexes begin to be expressed.

Metabolic assessment of female chronic dieters with either normal or low resting energy expenditures.

BACKGROUND: Chronic dieting syndrome can have negative physiologic and psychological consequences. Metabolic differences between female chronic dieters with normal and with low resting energy expenditures (REEs) have not been fully examined. OBJECTIVE: To determine whether differences existed between 2 groups (n = 15/group) of female chronic dieters aged 21-49 y with either normal (>/=100% of predicted) and with low (

State control in the substance-exposed fetus. I. The fetal neurobehavioral profile: an assessment of fetal state, arousal, and regulation competency.

Behavioral states are stable structures of behaviors that become more definable and coordinated with increasing age. With ultrasound we can see the fetus move, breathe, and react to changes in its environment. Ultrasound used in conjunction with Doppler fetal heart rate recording provides behavioral and neurophysiologic data useful in state determination. The Fetal Neurobehavioral Profile (FNP) was developed by our group as an assessment of fetal behaviors reflecting CNS integrity in the drug-exposed fetus. The FNP was designed to parallel methods of examining the newborn infant, especially in state-related behaviors. The FNP measures: fetal responsiveness and arousal after environmental perturbation with vibroacoustic stimulation (VAS); habituation to VAS; state recovery; and self-regulation post-VAS. From the behavioral and physiologic recordings, the constructs of state differentiation, organization, and regulation as well as fetal arousal and regulation competency can be measured. Previous work using the FNP showed that those fetuses with abnormal or suspect fetal state regulation demonstrated impaired performance on the NBAS (Am. J. Obstet. Gynecol. 161: 685, 1989). To expand these observations, three populations are currently being studied: prenatal nicotine-exposed, prenatal cocaine-exposed, and controls. Data are from 97 women/fetus dyads and a total of 236 FNP at ages 28-30 weeks gestational age, 31-34 weeks gestational age, and > 36 weeks gestational age. Although there are no group differences in the ability to achieve state by 36 weeks, interesting trends emerge: fetuses prenatally cocaine-exposed spend less time in 1F, more time in 4F and have fewer transitions. At FNP, fewer cocaine-exposed fetuses had an initial reaction to VAS, whereas fewer nicotine-exposed fetuses habituated. Although the ability to habituate to VAS did not discriminate the cocaine group from the control or nicotine groups, the number of stimuli required for habituation differed between groups: 7 for the cocaine-exposed, 3 for the nicotine, and 5 for the control groups. Thus latency, a measure of arousal, differs among the groups Preliminary data also suggest a correlation of prenatal data with postnatal outcome.

Developmental characteristics of substance P immunoreactivity within specific rabbit brainstem nuclei.

Microdissected areas of the rabbit brainstem were isolated at prenatal day E28, postnatal days P3, 7, 14, 21, at 2 months and adults. Substance P immunoreactivity (SPI) was assayed by RIA and SPI was expressed relative to the protein content of the extracted brain tissues. The developmental characteristics of SPI within specific brainstem nuclei are reported. In general, SPI was highest in the NTS (nucleus tractus solitarii) at all ages. The pattern of distribution of SPI, however, was age-specific. The development of SPI within select nuclei demonstrated marked variability and showed both age- and nucleus-specificity.

The development of synaptophysin-like immunoreactivity in the lumbosacral enlargement of the spinal cord of the opossum Monodelphis domestica.

The presence of synaptophysin in the lumbosacral enlargement of developing opossums, Monodelphis domestica, was studied immunohistochemically at the light microscopic level. In newborn, synaptophysin-labeling was observed in the presumptive white matter, presumably in growing axons, and was scant in the ventrolateral gray matter. Over the next 3 weeks the labeling filled the gray matter following a general ventrodorsal gradient. Labeling was found in the white matter until the fifth week. Synaptogenesis in the lumbosacral enlargement of the opossum thus occurs mostly postnatally, when many descending axons have already reached that level. It is particularly intense in the ventral horn when the hindlimbs begin to move, and in the dorsal horn when sensorimotor reflexes can be elicited.

The development of an empirical psychosocial taxonomy for patients with diabetes.

The main purpose of this study was to develop and to cross-validate an empirically derived psychosocial taxonomy of patients with diabetes. In the first study, 101 patients with Type I or Type II diabetes completed the Multidimensional Diabetes Questionnaire. Cluster analysis identified three clusters, labeled adaptive copers, low support-low involvement, and spousal overinvolvement. In the second study, the taxonomy was cross-validated using an independent sample of 132 patients with long-standing Type II diabetes. The results confirmed that the multivariate classification system was unique and highly accurate. External validation, using general psychological as well as diabetes-specific measures, supported the validity and distinctiveness of the patients' profiles. These findings help establish a multiaxial psychosocial taxonomy of diabetes and may have significant implications for the management of patients with diabetes.

Relations of diabetes intrusiveness and personal control to symptoms of depression among adults with diabetes.

The generalizability of a model linking illness characteristics to psychosocial well-being was tested in a cross-sectional study of 237 adults with type 2 diabetes. It was hypothesized that diabetic complications increase illness intrusiveness, which in turn increases depressive symptomatology either directly or indirectly by reducing personal control over health outcomes. Illness intrusiveness was defined as the result of disruptions of valued activities and interests due to constraints imposed by the illness. An excellent fit of this model to the data was found using structural equation modeling. The model explained 65% of the variance in depressive symptomatology. Assessment of an alternative model excluding personal control suggested that the extent to which diabetes intrudes in life, rather than diabetic complications per se or personal control, is a key factor in relation to depressive symptomatology in individuals with diabetes.

Prenatal cocaine exposure alters postnatal hypoxic arousal responses and hypercarbic ventilatory responses but not pneumocardiograms in prenatally cocaine-exposed term infants.

To test the hypothesis that respiratory control is altered in cocaine-exposed infants, we evaluated the hypoxic arousal response and the ventilatory response to carbon dioxide (CO2) in 18 term newborn infants prenatally exposed to cocaine and in 10 healthy, term newborn infants within the first week of life. Three infants could not be tested for the hypoxic arousal response because of low baseline oxygen saturation, and data from these infants were excluded from analysis. Twelve hour overnight pneumocardiograms were performed on all infants. Results show that 60% (9/15) of the prenatally cocaine-exposed infants had an abnormal hypoxic arousal response and 87% (13/15) had abnormal hypercarbic ventilatory response. Only 6% (1/15) of the prenatally cocaine-exposed infants demonstrated any abnormality on pneumocardiogram. In contrast, all control infants (10/10) were aroused by the hypoxic challenge and 80% (8/10) had normal ventilatory response to CO2. No abnormalities were found in the assessment of the overnight pneumocardiogram in the control infants. For the cocaine-exposed infants, test abnormalities were not correlated with a concurrent positive urine toxicology for cocaine, suggesting that the injury occurs early in development. These findings support the hypothesis that infants prenatally exposed to cocaine demonstrate abnormalities of respiratory control.

Developmental characteristics in the daily rhythm of norepinephrine concentration within rabbit brainstem regions.

To examine the development of daily variations in norepinephrine levels, norepinephrine concentrations were measured within five distinct brainstem regions in 3-day-old, 21-day-old, and adult rabbits at 6-h intervals throughout the day. Norepinephrine was measured by radioenzymatic assay, and norepinephrine concentration was expressed relative to wet tissue weight. The data suggest that daily variations for norepinephrine concentrations are established by the third day of life. In the brainstem as a whole, there was an early nocturnal peak (2130 hours) for 3-day-old animals in contrast to a late nocturnal peak (0330 hours) for 21-day-old animals. Adult animals showed a late diurnal (1530 hours) peak. These gross daily variations constitute the sum of distinct region-specific patterns in the development of daily variations in norepinephrine concentration. Norepinephrine is involved in cardiorespiratory regulation and in the regulation of sleep/wake cycles. The observed developmental patterns may relate to the maturation and integration of these physiologic processes.

Prenatal cocaine and/or nicotine exposure in rats: preliminary findings on long-term cognitive outcome and genital development at birth.

Prenatal cocaine or nicotine exposure is associated with a variety of teratogenic effects. The current study was conducted to determine their effects alone and in combination on cognitive function and sexual differentiation. Pregnant Long-Evans rats (N = 19) were exposed to either cocaine (15 mg/kg/dose b.i.d. SC on GD 8-20); nicotine (4 mg/kg/day continuous SC infusion on GD 4-20); both nicotine + cocaine; or vehicle only. Birth weight and anogenital distance (AGD) were measured in all pups at birth. Learning and memory were tested in the Morris water maze (MWM) during prepubertal and pubertal ages in five daily consecutive sessions and a sixth session 1 week later and in the radial-arm maze (RAM) during adulthood. In the RAM, a drug challenge of the beta-noradrenergic antagonist propranolol (10-20 mg/kg) was given after acquisition training. Maternal weight gain was reduced 13-42% and offspring birth weight was reduced by 7-12% in all three exposure groups compared to controls. Cocaine decreased the AGD of males (2.68 mm) compared to 2.88 mm in noncocaine-exposed male pups (p < 0.025). A sex-selective cocaine effect was also seen after adjustment of AGD measurements for body weight. With this measure cocaine-treated females showed significantly (p < 0.05) greater AGD than those not exposed to cocaine. In the MWM, there were two types of trials: cued reference memory trials and uncued spatial working memory trials. On cued reference memory trials significant cocaine-induced latency deficits were seen on only the first session. On spatial working memory trials cocaine-induced latency deficits were seen throughout daily training on sessions 1-5, but not the retention session 6, 1 week later. During RAM acquisition, there were no significant differences in choice accuracy between exposure groups. Following propranolol challenge, deficits in choice accuracy were demonstrated in rats prenatally exposed to cocaine or nicotine. These rats did not show any response to propranolol, whereas the controls slightly improved their choice accuracy. The results of this study indicated that prenatal cocaine exposure altered long-term cognitive function under basal conditions in the MWM and drug challenge in the RAM, birth weight, and genital development. Cocaine-induced cognitive deficits were predominately in working memory rather than reference memory or long-term retention. Prenatal nicotine exposure was only observed to alter birth weight and cognitive function in response to propranolol challenge in the RAM.

Cocaine and development: mechanisms of fetal toxicity and neonatal consequences of prenatal cocaine exposure.

As cocaine use during pregnancy has become increasingly recognized, there also has been increased concern about the toxic and teratogenic properties of cocaine on the fetus. A significant literature exists describing the adverse fetal and neonatal outcomes associated with in utero cocaine exposure. However, specific causality by cocaine on outcome in the human is difficult to ascertain because of multiple confounding variables associated with substance abuse including social factors and polydrug use as well as difficulty in confirming timing, dose and frequency of cocaine exposure. Most literature suggests that prenatal cocaine exposure is associated with developmental risk to the fetus. What is currently unknown is the extent of risk, the additive and/or synergistic factors contributing to cocaine's toxicity and the reversibility of the injury. In this paper we review the pharmacologic properties of cocaine as related to a model of mechanisms for developmental injury secondary to cocaine exposure and the published literature on the adverse fetal and neonatal outcomes associated with cocaine use during pregnancy. Specific attention has been focused on the structural, neurobehavioral and respiratory control teratogenesis.

Maternal polydrug use including cocaine and postnatal infant sleep architecture: preliminary observations and implications for respiratory control and behavior.

Twelve-hour overnight pneumocardiograms were assessed for sleep architecture and sleep efficiency in two groups of healthy term newborn infants: a group exposed prenatally to cocaine alone or in combination with other drugs and a non-exposed group. Sleep was differentiated from wakefulness by an increase in heart rate, an increase in or variation in the duration and amplitude of the respiration and increased artifacts on the heart rate channel. Quiet and active sleep were determined by the regularity or irregularity of heart rate and respiration. In a sub-set of infants, the number of arousals during active sleep was calculated. Overall significance was confirmed by ANOVA followed by paired comparisons using the Student's-test. When compared to non-exposed infants within the first week of life, infants exposed prenatally to cocaine alone or in combination with other drugs demonstrated more wakefulness and less sleep (P < 0.05), more frequent arousals during active sleep (P < 0.01), and the tendency of a higher proportion of active sleep compared to quiet sleep. These findings may have implications to both behavioral and respiratory control findings associated with prenatal cocaine exposure.

Maternal cocaine addiction. II: An animal model for the study of brainstem mechanisms operative in sudden infant death syndrome.

Respiratory control abnormalities are mechanistic in Sudden Infant Death Syndrome (SIDS). In particular, arousal form sleep is an important component of respiratory regulation. Cocaine alters central neurotransmitter metabolism, particularly the monoamines. The locus coeruleus, the major Norepinephrine (NE) neuronal system, is involved in arousal from sleep related apnea and has extensive forebrain and brainstem projections. Thus, it is plausible that in utero cocaine exposure disrupts the normal maturation of transmitters and/or brain structures essential to sleep related respiratory regulation. Infants exposed to cocaine in utero may have an increased incidence of SIDS. We propose that cocaine use in pregnancy alters the normal maturation of centers and/or neurotransmitters involved in respiratory regulation thereby altering postnatal respiratory control. We hypothesize that the increased incidence of SIDS in cocaine exposed infants may be secondary to deficits in arousal. The study of prenatal brain development and of postnatal respiratory control in rabbit pups exposed to cocaine in utero will provide a useful model for the study of mechanisms operative in SIDS.

Maternal cocaine addiction and fetal behavioral state. I: A human model for the study of sudden infant death syndrome.

Abnormalities of respiratory regulation, such as apnea and abnormal hypoxic arousal during sleep, are mechanistic in the pathophysiology of SIDS. In utero cocaine exposure is associated with poor head growth, abnormal neurodevelopment, and an increased incidence of sudden, unexplained death, suggesting that in utero cocaine exposure disrupts the central regulation of breathing. It is likely that this disruption is due to altered CNS maturation. Indeed, cocaine alters norepinephrine metabolism within the locus coeruleus, important in arousal from sleep, suggesting that the increased incidence of SIDS in cocaine exposed infants may be secondary to sleep-related deficits in arousal. Since components of fetal behavioural state organization reflect the successful integration of the Central Nervous System, have a specific developmental timetable, and can be studied by fetal ultrasound techniques, we developed a strategy for assessing the state organization of the fetus by ultrasound techniques. We hypothesize that fetal evaluation of state will be a marker of abnormal CNS maturation and a predictor of risk, i.e. abnormal neurodevelopment and/or state related arousal deficits predisposing the cocaine exposed neonate to SIDS. We propose that the study of in utero cocaine exposed fetuses will provide a human model for examining the pathophysiology of SIDS.

Agrin becomes concentrated at neuroeffector junctions in developing rodent urinary bladder.

The formation of somatic neuromuscular junctions in skeletal muscle is regulated by an extracellular matrix protein called agrin. Here, we have examined the expression and localization of agrin during development of the rodent urinary bladder, as a first step to examining its possible role at autonomic neuroeffector junctions in smooth muscle. We have found that agrin is expressed on the surface of developing smooth muscle cells and in the basement membrane underlying the urothelium. More importantly, agrin is progressively concentrated at parasympathetic varicosities during postnatal development and is present at virtually all junctions in mature muscle. Reverse transcription/polymerase chain reaction analysis has shown that pelvic ganglion neurons that innervate the bladder express LN/z8 agrin, whereas bladder smooth muscle expresses LN/z- agrin. Together, these results demonstrate that nerve and/or muscle agrin becomes localized at cholinergic parasympathetic varicosities in smooth muscle, where it could play a role in the maturation of the neuroeffector junction.

Expression and localization of agrin during sympathetic synapse formation in vitro.

Agrin is a motoneuron-derived signaling factor that plays a key organizing role in the initial stages of neuromuscular synapse formation. Agrin is expressed in other regions of the developing central and peripheral nervous systems, however, raising the possibility that it also directs the formation of some interneuronal synapses. To address this question, we have examined the expression and localization of agrin during formation of cholinergic, interneuronal synapses in the sympathetic system. In the superior cervical ganglia (SCG) in vivo, we found that agrin is highly expressed, and that it is present at, but is not limited to, synapses. In SCG neuronal cultures that were treated with ciliary neurotrophic factor to induce a uniform cholinergic phenotype, we found that agrin immunostaining colocalized precisely with cholinergic terminals and aggregates of neuronal acetylcholine receptor on the neuronal cell bodies and dendrites. Moreover, we found that alpha-dystroglycan, which is a potential receptor for agrin, is also concentrated at these cholinergic synaptic contacts. Finally, the SCG neurons expressed the C-terminal isoform of agrin that is neural-specific and highly active in synaptogenesis, and also the N-terminal splice isoform that occurs as a type II transmembrane protein. These findings show that agrin is specifically localized at sympathetic synapses in vitro, and are consistent with it playing a role in interneuronal synapse formation.

Chronic maternal hypoxia. Effect of mid-gestational maternal hypoxia on methionine-enkephalin concentrations within pre- and postnatal rabbit brainstem regions.

We examined the effect of chronic maternal hypoxia on methionine-enkephalin concentrations in fetal (gestational day E-28) and neonatal (postnatal days 3, 7, 21) brainstem regions. Pregnant rabbits were housed in environmental chambers at gestational day E-10. Between E-14 and E-28 the pregnant rabbits were separated into two groups. Group I were controls (C) and breathed 21% O2/79% N2 and group II, hypoxia (H), breathed 12-14% O2/86-88% N2. Sacrifice occurred at various days depending on the experimental paridigm. On gestational day E-28, the first group of 6 pregnant animals (3 C, 3 H) were delivered by hysterotomy and the pups were immediately sacrificed. On and after gestational day E-28, the remaining 12 pregnant animals breathed room air. These animals delivered spontaneously between 30 and 32 days of gestation. The pups remained with their mothers until sacrifice. On postnatal days 3, 7, or 21, methionine-enkephalin was measured by radioimmunoassay in the colliculi (fetal animals), superior and inferior colliculi (postnatal animals), pons and medulla (both groups). In both normoxia-exposed and hypoxia-exposed animals, methionine-enkephalin was highest in the medulla, intermediate in the pons, and lowest in the colliculi. Chronic maternal hypoxia significantly increased the methionine-enkephalin concentration in the pons of E-28 fetuses (p less than 0.02). Levels were increased in the medulla as well but these did not reach significance (p = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)