Lifetime brain serotonin: regional effects of age and precursor availability.

In the rat, regional brain serotonin levels which do not change from 2-30 months of age are increased at 36 months. Corresponding catecholamine levels progressively decrease. Feeding a diet restricted in the amino acid tryptophan (the precursor of serotonin) from weaning to two years of age markedly reduces serotonin levels in all brain regions and lowers norepinephrine levels in the cerebral hemispheres. Regional activity of synthesizing (tyrosine and tryptophan hydroxylases) and catabolizing enzymes (MAO-A) does not change markedly with age or dietary manipulation except for sporadic increases in tryosine hydroxylase activity in pair-fed animals. Returning the tryptophan-deficient animals to a normal diet produces a certain degree of rehabilitation the effectiveness of which varies with the function considered: Impaired brain serotonin levels recover moderately but remain lower than controls as late as 36 months, growth is never completely compensated, and norepinephrine levels show a rebound increase.

Monoamine metabolism in the developing rat brain and effects of ionizing radiation.

Neonatal X-radiation induces profound changes in monoamine metabolism in the developing CNS. NE and 5-HT concentrations increase 7 days post-radiation in all CNS regions undergoing rapid axonal growth and proliferation, but not in the region of the cell bodies from which the respective neurotransmitters originate. The increase in NE and 5-HT levels is accompanied by a concomitant increase in the rate of synthesis. While these changes are evident as late as 22 days of age, the monoaminergic systems revert to normal by maturity. It is suggested that these alterations reflect an imbalance in the density of nerve endings to the region where these terminate. These regions are immature at birth and cell proliferation, a process which is affected by X-radiation, is still occurring at the time of exposure.

Bovine trichomoniasis: Results of a slaughter survey in Colorado and Nebraska.

A total of 2,909 bulls was cultured for the presence of Trichomonas fetus at slaughter at 4 abattoirs in Colorado and Nebraska. Samples were collected using the dry pipette preputial scraping technique and were transported to diagnostic laboratories within 24 h. Of the bulls cultured, 5 were positive. The state of the last origin for each animal was Kansas, 1 bull, Montana, 1 bull, Nebraska, 1 bull, and Utah, 2 bulls. These results indicate and incidence of less than 1% (0.172%) of trichomoniasis in the populations tested, even in the states of Colorado and Nebraska where the larger numbers of bulls were cultured.

Development and testing of a bovine trichomoniasis vaccine.

Eighteen culled dairy cows were randomly allocated into 1 of 5 treatment groups. Six cows were vaccinated twice (2V), 21 days apart, 3 with whole cell (2WC) and 3 with fragmented cell membrane (2FC) containing 1 x 10(9)Trichomonas fetus organisms or protein equivalent in a commercial mineral oil adjuvant vaccine. Six more cows were vaccinated once (1V), 3 with whole cell (1WC) and 3 with fragmented cell vaccine (1FC), using the same vaccine, while 6 cows were used as the unvaccinated controls. All cows were challenged with 1 x 10(5) organisms 4 weeks after the second or the only vaccination. After challenge, cervico-vaginal mucus (CVM) samples were cultured for T . fetus weekly for 9 weeks. Whole cell vaccines were superior to fragmented cell vaccines, and both performed better than no vaccination for apparent elimination of trichomonad infections in dairy cows. In addition, 2V was superior to 1V, which, in turn, was superior to no vaccination. Furthermore, clearance time was reduced most by 2V and whole cell vaccination compared with 1V and fragmented cell vaccination. Clearance time was decreased significantly in all vaccinated cows compared with that in unvaccinated cows.

Testing of trichomoniasis vaccine in heifers mated to infected bulls.

This study was conducted to evaluate the effectiveness of a Trichomonas fetus vaccine to protect heifers from infection when bred to infected bulls. The vaccine consisted of a whole cell vaccine of T. fetus organisms stabilized in formaldehyde and adjuvanted in a mineral oil base. In the trial, fewer vaccinated heifers became infected than unvaccinated controls (69.4 vs 93.0%, respectively; P<0.08). The vaccinated heifers tended to clear the infections sooner than the controls (48.9 vs 68.5 days, respectively; P<0.10). The average number of days open was shorter in the vaccinated heifers than in the controls (33.2 vs 56.9 days, respectively; P<0.07). The first service conception rate was higher in the vaccinated heifers than in the controls (66.7 vs 33.3%, respectively; P<0.05). The number of services per conception in conceiving heifers was lower in vaccinated than in control heifers (1.44 vs 1.73, respectively; P<0.16). Cervicovaginal mucus (CVM) samples were collected every 14 days following first challenge (first service). On average, more CVM samples were positive for T. fetus for a longer period of time in the control than in the vaccinated heifers (3.9 vs 1.85 sampling periods, respectively; P<0.08). We concluded that, under the conditions of this trial, some protection to T. fetus was afforded by double vaccination with a whole cell vaccine. However, vaccination does not completely prevent heifers from developing infection.

Adolescents' perceptions of pain during labor.

This descriptive study systematically described the quality and intensity of adolescents' pain during the progression of labor. The Gaston-Johansson Pain-o-Meter was administered to 33 adolescents during the three labor phases (2-4 cm, 5-7 cm, and 8-10 cm) following a contraction. The most frequently selected sensory words were cramping in Phase I and pressing in Phases II and III. Miserable and killing were the most commonly chosen affective words during the three labor phases. Using the Gaston-Johansson Pain-O-Meter and the Gaston-Johansson Pain-O-Meter Visual Analogue Scale, the total pain intensity scores were highest during phase III of labor and delivery. At-test of independent samples found that quality and intensity pain scores for primiparous and multiparous adolescent participants were not significantly different during the progression of labor. The findings of the study illustrate the value of using objective measures, such as the Gaston-Johansson Pain-O-Meter and the Gaston-Johansson Pain-O-Meter Visual Analogue Scale, to assess pain during labor. The study also demonstrated that nurses can use these tools with minimal training.

PIP: To enable nurses to provide optimal pain management to adolescents during labor, a descriptive study was conducted of the quality and intensity of such pain at different stages of labor. Enrolled was a convenience sample of 24 primiparous and 9 multiparous women 16-19 years old (mean, 17.78 years) who entered a Nebraska hospital in full labor. The interactive Gaston-Johansson Pain-O-Meter was used to measure the affective, sensory, and intensity components of pain. The sensory words selected most frequently during the three stages of labor were "cramping" (46%), "pressing" (39%), and "pressing" (42%), respectively, while the most common affective terms were "killing" (52%), "miserable" (36%), and "killing" (79%). The highest mean affective and sensory pain scores were reported during the second stage of labor. Primiparas experienced the lowest pain levels during phase I of labor and the highest during phase II, while multiparas' mean scores increased as labor progressed; however, there were no significant differences in mean pain scores by parity. The study was not able to take into account the impact of variables such as self-efficacy, anxiety, analgesics, childbirth education class attendance, and length of labor on pain perceptions. Knowledge of the intensity of pain, and whether it is primarily affective or sensory, can assist nurses to develop individualized interventions for adolescents experiencing labor pains.

First-time mothers' and fathers' transition to parenthood: infant care self-efficacy, parenting satisfaction, and infant sex.

The threefold purposes of our study were to determine differences between first-time mothers' and fathers' development of infant care self-efficacy and parenting satisfaction, relationships between mothers' and fathers' infant care self-efficacy and parenting satisfaction, and the effect of infant sex on the development of mothers' and fathers' infant care self-efficacy and parenting satisfaction during the first 4 months following the infant's birth. A convenience sample of 44 couples in a midwestern state completed the Demographic Questionnaire, the Infant Care Survey, and What Being the Parent of a New Baby is Like-Revised. Fathers' reports of infant care self-efficacy increased linearly during the first 4 months following the infant's birth while mothers' reports of infant care self-efficacy increased linearly during the first 3 months. At all data collection times, fathers reported significantly lower infant care self-efficacy than mothers. Reports of parenting satisfaction increased over time for mothers and fathers. At 8, 12, and 16 weeks following the infant's birth, mothers' infant care self-efficacy scores were significantly related to their parenting satisfaction scores. Fathers' infant care self-efficacy scores were significantly related to their parenting satisfaction scores at 12 and 16 weeks. Fathers of male infants had significantly higher parenting satisfaction scores than fathers of female infants at 12 and 16 weeks following the infant's birth. Nurses can develop individualized interventions to assist mothers and fathers during the transition to parenthood.

Young Parents Project: a 21st-century nursing intervention.

The purpose of this exploratory, descriptive pilot study was to describe the usage of the Young Parents Project, a computer network offering health information and support, to adolescent mothers. Nine midwestern adolescent mothers were provided a computer so they could access the Young Parents Project in their homes. Participants gained access to the computer network 834 times for a total of 7,046 minutes during the year of the study. Adolescent mothers read and posted 402 electronic messages to one another and 110 electronic mail messages to advanced practice nurses. The following eight themes emerged when participants' electronic messages were analyzed using content analysis: introductions, emotional support, social support systems, infant sharing, infant issues, postpartum issues, finances and education, and computer support. The adolescent mothers' evaluation of the Young Parents Project was primarily positive, and the project served as a mechanism for providing health information and social support to adolescent mothers.

Depression, self-esteem, loneliness, and social support among adolescent mothers participating in the new parents project.

The purpose of this pilot study was to examine levels of depression, self-esteem, loneliness, and social support, and the relationships between these variables, among adolescent mothers participating in the New Parents Project (formerly called the Young Parents Project). The sample consisted of 21 adolescent mothers recruited from three primary health care practices in different Midwestern cities. It was found that depression scores were in the high range (CES-DC > 15) for 53% of the participants. Strong, significant relationships were found, except between depression and self-esteem. The implications for enhancement of the New Parents Project, so as to better meet the psychological needs of adolescent mothers, are discussed.

Expectant parents' experience with fatigue and sleep during pregnancy.

BACKGROUND: Although both expectant mothers and expectant fathers complain of fatigue during the last trimester of pregnancy, studies have focused exclusively on mothers. This pilot study examined parents' levels of morning or evening fatigue, number of uninterrupted sleep periods and length of sleep during the last trimester of pregnancy; and the relationship of sleep to parents' reports of fatigue. METHODS: Data were collected from 24 midwestern, nulliparous couples, who completed the Visual Analog Scale for Fatigue each morning and each evening on 4 consecutive days during the last trimester. Concurrently, the couples recorded sleep and wake periods in an activity diary. RESULTS: Expectant mothers but not expectant fathers reported increasing levels of fatigue, especially morning fatigue, as the pregnancy progressed. Expectant fathers and mothers did not differ either in the night-time mean number of minutes of sleep obtained, or in the mean number of night-time uninterrupted 90-minute sleep cycles obtained. Fatigue and sleep were not significantly related for either mothers or fathers. CONCLUSIONS: These findings support the multidimensional nature of fatigue and indicate a need for perinatal health caregivers to develop individualized interventions for mothers during the last trimester of pregnancy. Fathers should also participate in future research of factors influencing the prenatal and postpartum experience.

Free amino acids in synaptic vesicles isolated from the cerebellum and cerebral hemispheres of control and neonatally X-irradiated rats.

X-irradiation of the rat brain (1000R, at two days of age), suppresses the normal age-related increase in the weight of the cerebellum and cerebral hemispheres and influences amino acid levels. The decrease in glutamic acid concentration, particularly in the cerebellum, supports the previously advanced proposition that this amino acid may be associated with or may be the transmitter of, the rat cerebellar granule cells. Subfractionation of the cerebellar tissue reveals that the decrease in the glutamic acid level consequent to the loss of granule cells, is reflected in the cytoplasmic fraction but not in the synaptic vesicle subfraction, where glutamic acid was increased. The reduced weight gain in the cerebral hemispheres after irradiation, is accompanied by a significant decrease of aspartate in the cytoplasmic fraction, changes which suggest that a specific cell type, with aspartic acid as its neurotransmitter (possibly in the hippocampus), may also be radiosensitive in the early postnatal period. In contrast, in the synaptic vesicle fraction from cerebral hemispheres, all free amino acids, with the exception of glutamine, increased significantly. Overall, the changes in free amino acid concentration induced by X-irradiation in the cytoplasmic fraction in both brain regions studied are opposite to those found in the synaptic vesicle fraction and although they may indicate changes in specific cell populations, as proposed above, they could also reflect changes in cellular compartmentalization and metabolism or changes in the relative axonal arborization of the affected regions.

Neuroendocrine pacemaker for growth, development and ageing.

The hypothesis is formulated that ageing is mediated through alteration in a pacemaker system located in the hypothalamus and dependent on serotonin-thyroid hormone interactions. Data in support of this hypothesis include: imbalance in central nervous system (CNS) neurotransmitters with ageing, with serotonin dominance; impairment of hypothalamic neurosecretion; increased heterogeneity of thyrotropin forms secreted from the aged pituitary; and drug and dietary manipulation of CNS serotonin with consequent effects on endocrine function and homeostasis.

Glutamic acid: A strong candidate as the neurotransmitter of the cerebellar granule cell.

Free amino acids and cholinergic enzymes were investigated in the cerebellum of reeler and weaver mice in an attempt to identify the neurotransmitter characteristic of the granule cell population and to clarify any neurotransmitter abnormalities of their pre- and postsynaptic neurons induced by their depletion. The data indicate that glutamic acid may be the neurotransmitter of the granule cells. Pre- and postsynaptic neurotransmitter activity seemed not to be markedly altered in cerebellar granule cell dysgenesis.

Protective effect of activated charcoal in cattle poisoned with atrazine.

Six heifers were poisoned with a lethal dose of atrazine. Three animals were treated daily for 4 days with activated charcoal. The untreated animals died within 3 days, whereas the treated animals survived the 14-day observation period. Hematology, blood chemistry and pathology findings are reported.