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Postconceptional Age (postconceptional + age)

Distribution by Scientific Domains
Medical Sciences60%

Kinds of Postconceptional Age

  • week postconceptional age
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    Selected Abstracts

    Development of Tactile Responses in Human Preterm and Full-Term Infants From 30 to 40 Weeks Postconceptional Age

    INFANCY, Issue 1 2002
    Isabel Fearon
    Maturation of tactile sensitivity prior to term was examined in 36 preterm and 13 full-term infants using a fixed-trial, habituation procedure. Each infant was presented with a series of 8 habituation (arm stroke), 2 novel (arm lift), and 2 recovery (arm stroke) stimulus trials while heart rate and body movements were recorded. Maturation was observed with a gradual increase in the magnitude of the stimulus-elicited cardiac acceleration and cardiac-movement coupling from 30 to 40 weeks postconceptional age. The majority of infants displayed habituation,an excitatory response (heart rate acceleration and body movement),to the initial presentation of a tactile stimulus, response decline with repeated stimulations, and renewed response to a novel stimulus. A substantial number of infants (40%) failed to respond initially to the tactile stimulus, increased responding over several stimulus presentations, and failed to discriminate the presentation of a novel stimulus. We speculate that these differences in response patterns observed over all ages represent individual difference in the perception of stimulus intensity. [source]

    Influences of postconceptional age and postnatal experience on the development of auditory recognition memory in the newborn infant

    DEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2002
    Raye-Ann deRegnier
    Abstract We evaluated the effects of postconceptional age and postnatal experience on the development of neonatal auditory recognition memory. Three groups were tested: a premature newborn group (tested at 35,38 weeks postconceptional age, ,1 week old), a full-term newborn group (tested at 39,42 weeks postconceptional age, ,1 week old), and a full-term experienced group (tested at 39,42 weeks postconceptional age, >1 week old; range 8,30 days). Event-related potentials were collected while infants listened to the maternal voice alternating with a stranger's voice. Postconceptional age was correlated with the development of recognition memory for the maternal voice while there were qualitative effects of postnatal experience on latency measurements. Maturity of auditory cortical responses was not correlated with recognition memory abilities. We conclude that maturation of the recognition memory pathways is primarily a function of postconceptional age with qualitative effects of postnatal experience. Maturation of the auditory recognition memory pathway is not contingent upon maturation of the "P2" peak thought to arise from primary auditory cortex. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 41: 216,225, 2002. Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/dev.10070 [source]

    Development of Tactile Responses in Human Preterm and Full-Term Infants From 30 to 40 Weeks Postconceptional Age

    INFANCY, Issue 1 2002
    Isabel Fearon
    Maturation of tactile sensitivity prior to term was examined in 36 preterm and 13 full-term infants using a fixed-trial, habituation procedure. Each infant was presented with a series of 8 habituation (arm stroke), 2 novel (arm lift), and 2 recovery (arm stroke) stimulus trials while heart rate and body movements were recorded. Maturation was observed with a gradual increase in the magnitude of the stimulus-elicited cardiac acceleration and cardiac-movement coupling from 30 to 40 weeks postconceptional age. The majority of infants displayed habituation,an excitatory response (heart rate acceleration and body movement),to the initial presentation of a tactile stimulus, response decline with repeated stimulations, and renewed response to a novel stimulus. A substantial number of infants (40%) failed to respond initially to the tactile stimulus, increased responding over several stimulus presentations, and failed to discriminate the presentation of a novel stimulus. We speculate that these differences in response patterns observed over all ages represent individual difference in the perception of stimulus intensity. [source]

    Proton spectroscopic metabolite signal relaxation times in preterm infants: A prerequisite for quantitative spectroscopy in infant brain

    JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2003
    Harald Kugel PhD
    Abstract Purpose To determine relaxation times of metabolite signals in proton magnetic resonance (MR) spectra of immature brain, which allow a correction of relaxation that is necessary for a quantitative evaluation of spectra acquired with long TE. Proton MR spectra acquired with long TE allow a better definition of metabolites as N-acetyl aspartate (NAA) and lactate especially in children. Materials and Methods Relaxation times were determined in the basal ganglia of 84 prematurely born infants at a postconceptional age of 37.8 ± 2.2 (mean ± SD) weeks. Metabolite resonances were investigated using the double-spin-echo volume selection method (PRESS) at 1.5 T. T1 was determined from intensity ratios of signals obtained with TRs of 1884 and 6000 msec, measured at 3 TEs (25 msec, 136 msec, 272 msec). T2 was determined from signal intensity ratios obtained with TEs of 136 msec and 272 msec, measured at 2 TR. Taking only long TEs reduced baseline distortions by macromolecules and lipids. For myo-inositol (MI), an apparent T2 for short TE was determined from the ratio of signals obtained with TE = 25 msec and 136 msec. Intensities were determined by fitting a Lorentzian to the resonance, and by integration. Results Relaxation times were as follows: trimethylamine-containing compounds (Cho): T1 = 1217 msec/T2 = 273 msec; total creatine (Cr) at 3.9 ppm: 1010 msec/111 msec; Cr at 3.0 ppm: 1388 msec/224 msec; NAA: 1171 msec/499 msec; Lac: 1820 msec/1022 msec; MI: 1336 msec/173 msec; apparent T2 at short TE: 68 msec. Conclusion T1 and T2 in the basal ganglia of premature infants do not differ much from previously published data from basal ganglia of older children and adults. T2 of Cho was lower than previous values. T2 of Cr at 3.9 ppm and Lac have been measured under different conditions before, and present values differ from these data. J. Magn. Reson. Imaging 2003;17:634,640. © 2003 Wiley-Liss, Inc. [source]

    Effect of an early intervention programme on low birthweight infants with cerebral injuries

    JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 12 2004
    S Ohgi
    Objective: To determine the effect of an early intervention programme (EIP) on low birthweight infants with cerebral injuries. Methods: Subjects were 23 high-risk low birthweight infants (periventricular leukomalacia 15, intraventricular haemorrhage 5, both 3) receiving care in the neonatal intensive care unit (NICU) at Nagasaki University Hospital. Subjects were randomly assigned to the EIP group (n = 12) or the control group (n = 11). Participants in the EIP group received a Neonatal Behavioral Assessment scale (NBAS)-based intervention combined with developmental support designed to enhance the infants' development and the quality of the parent,infant relationship. The control group received routine medical nursing care without the EIP. The EIP began prior to discharge from the NICU and lasted until 6 months of corrected age. All children were examined on the NBAS preintervention and again at 44 weeks postconceptional age. Maternal anxiety status (STAI) and maternal feelings of confidence in dealing with her baby (LCC) were measured pre and postintervention. Mental and motor development was assessed postintervention using the Bayley Scale of Infant Development. Results: Orientation and State Regulation of infant behavioural profiles, the STAI and LCC scores significantly improved in the EIP group (mean difference (95% CI): Orientation 0.7 (0.4, 1.1), State Regulation 0.9 (0.3, 1.5), STAI ,5.5 (, 9.1, ,1.9, LCC 5.3 (4.2, 6.5)), but not in the control group. Bayley mental developmental index (MDI) score in the EIP group was higher than in the control group, but there was no significant difference between the two groups (mean difference (95% CI): MDI 8.5 (, 0.8, 17.8), PDI 6.7 (, 1.9, 15.4)). Conclusion: The EIP has beneficial effects on neonatal neurobehavioural development and maternal mental health of low birthweight infants with cerebral injuries. This evidence suggests that short-term changes in maternal mental health and infant neurobehaviour promoted by an EIP may serve to initiate a positive interaction between parents and infants. [source]

    Effect of dexamethasone therapy on pulmonary function in chronic lung disease: A comparison of disease types

    PEDIATRICS INTERNATIONAL, Issue 3 2001
    Masami Mizobuchi
    Abstract Background: In the present study, we investigated the effect of dexamethasone (DEX) therapy on extubation and pulmonary function in patients with chronic lung disease (CLD) who required long-term mechanical ventilation. In addition, we compared the effects of DEX therapy among CLD types. Methods: Twenty-two CLD patients who were ventilator dependent for 28 days or longer received DEX therapy for the purposes of extubation. A tapering dose of DEX, starting from 0.5 mg/kg per day, was administered for 7 days. Pulmonary function was measured at initiation of administration and 4 days after initiation. We evaluated static respiratory system compliance (Crs) and static respiratory system resistance (Rrs) adjusted by bodyweight. Chronic lung disease types were categorized according to the classification of the Ministry of Health and Welfare Research Project. We compared the effect of DEX therapy among CLD types. Results: Dexamethasone therapy was started at a mean (±SD) 45±11 days after birth and 32.1±1.3 weeks of postconceptional age in infants with a mean bodyweight of 939±153 g. After DEX therapy, extubation was successful in all 22 patients. Following DEX administration, Crs was significantly increased from 0.69±0.13 to 1.17±0.21 mL/cm H2O per kg. In contrast, Rrs did not show any clear changes. Comparing CLD types, no difference was observed for Crs and Rrs in each disease type. Conclusions: Dexamethasone was administered to CLD patients requiring long-term mechanical ventilation for the purposes of extubation and extubation was successful in all patients. It was found that Crs was increased in all patients following DEX, regardless of CLD type. The increase in Crs following DEX administration may have been related to successful extubation. [source]

    Biological rhythm development in preterm infants: Does health status influence body temperature circadian rhythm?

    RESEARCH IN NURSING & HEALTH, Issue 3 2001
    Karen A. ThomasArticle first published online: 18 JUL 200
    Abstract Twenty-six preterm infants, postconceptional age from 28 to 35 weeks and postnatal age approximately 14 days, were included in a study of the development of temperature circadian rhythm. Insulated abdominal skin temperature and incubator air temperature were recorded continuously at 1-min intervals for 24 hr. Using cosinor analysis, cycle mesor, amplitude, and acrophase were determined. Initial results from regression analysis did not confirm a predicted linear relationship between postconceptional age and amplitude; however, dividing the sample according to health status into sick (N,=,15) and not sick (N,=,11) groups revealed differing regression models. For not sick infants, amplitude increased with postconceptional age (R2,=,.405), whereas no relationship was found between postconceptional age and cycle amplitude in sick infants (R2,=,.069). These results indicate that healthy preterm infants demonstrate emergence of circadian temperature rhythm. Implications include potential time-based periods of vulnerability, overheating and hyperthermia, and management of incubator operation. © 2001 John Wiley & Sons, Inc. Res Nurs Health 24: 170,180, 2001 [source]