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Postnatal Age (postnatal + age)

Distribution by Scientific Domains
Medical Sciences60%
Life Sciences32%
2 Other Domains8%
Distribution within Medical Sciences
Pediatrics53%
Neurology11%

Kinds of Postnatal Age

  • different postnatal age
    		•

    Selected Abstracts

    Abnormalities in the coordination of respiration and swallow in preterm infants with bronchopulmonary dysplasia

    DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 7 2006
    Ira H Gewolb MD
    Individual rhythms of suck, swallow, and respiration are disrupted in preterm infants with bronchopulmonary dysplasia (BPD). Integration of respiration into suck-swallow efforts is critical for establishing coordinated suckle feeding. This study quantitatively assessed the coordination of respiration and swallow in infants with and without BPD. Thirty-four preterm infants of 26 to 33 weeks'gestational age were included: 14 participants with BPD (eight males, six females) and 20 comparison participants without BDP (10 males, 10 females). Participants were studied at postmenstrual age 32 to 40 weeks and postnatal age 2 to 12 weeks using digital recordings of pharyngeal pressure, nasal thermistor flow, and thoraco-abdominal plethysmography. The coefficients of variation (COV; standard deviation/mean) of the swallow-breath (SW-BR) and breath-breath (BR-BR) intervals during swallow runs, the percentage of,apneic swallows'(runs of ,3 swallows without interposed breaths), and phase relationships of respiration and swallow were used to quantify rhythmic coordination and integration of respiration into feeding episodes. Apneic swallows were significantly increased after 35 weeks in infants with BPD (mean 13.4% [SE 2.4]) compared with non-BDP infants (6.7% [SE 1.8];p < 0.05), as were SW-BR phase relationships involving apnea. The BPD cohort also had significantly higher SW-BR COV and BR-BR COV than non-BPD infants, indicating less rhythmic coordination of swallowing and respiration during feeding. Results emphasize the need for frequent rests and closer monitoring when feeding infants with respiratory compromise. Quantitative assessment of the underlying rhythms involved in feeding may be predictive of longer-term feeding and neurological problems. [source]

    How Do Mothers Feel About Their Very Low Birth Weight Infants?

    INFANT MENTAL HEALTH JOURNAL, Issue 2 2006
    Development of a New Measure
    The early relationship between a mother and her very low birth weight (VLBW; <1.5 kg) infant may be difficult to evaluate. Therefore, we aimed to develop a useful and practical method to describe a mother's early relationship with her VLBW infant. Mothers (mean age=27 years, 46% married) of 119 singleton VLBW infants (mean BW=1,056 g, mean GA=28 weeks) admitted to the neonatal ICU at Rainbow Babies and Children's Hospital completed a novel questionnaire regarding their feelings about their infant at 3 weeks' postnatal age, and at 35 weeks', 40 weeks' (term), and 4 months' postmenstrual ages. Factor analysis of initial interview data was used to construct subscales to measure unique domains hypothesized to underpin the beginning maternal,infant relationship. Three subscales were identified: (a) The Worry subscale focuses on the mother's concerns about her infant's current medical condition and future development, (b) the Enjoyment subscale examines the mother's positive feelings about and responsiveness to her infant, and (c) the Separation Anxiety subscale examines the mother's mental anxiety about being physically separated from her infant. Statistical and clinical validation of the subscales produced positive supporting evidence that the subscales are a meaningful measure of the mother,infant relationship. We have developed a unique and practical measure for describing the early mother,VLBW infant relationship. [source]

    Significant differences between capillary and venous complete blood counts in the neonatal period

    INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 1 2003
    S.M. Kayiran
    Summary The normal capillary and venous hematologic values for neonates have not been defined clearly. It is well known that capillary blood has higher hemoglobin (Hb) and hematocrit (Hct) values than venous blood. In a recent study, we reported differences between capillary and venous complete blood counts (CBC) in healthy term neonates on day 1 of life. The aim of this study was to extend our previous investigation. Term neonates (n=141) were stratified into four groups by days of postnatal age: group 2 (day 7, n=38), group 3 (day 14, n=35), group 4 (day 21, n=32) and, group 5 (day 28, n=36). Data from our previous study were included in the statistical analysis as group 1 (day 1, n=95). A CBC and differential count were carried out on each capillary and venous sample drawn simultaneously. Within each group, the mean and standard deviation for each parameter in capillary and venous blood were calculated and then compared using the paired sample t -test. In all groups, the capillary blood samples had higher Hb, Hct, red blood cell (RBC), white blood cell (WBC), and lymphocyte counts. In each group, venous platelet counts were significantly higher than the corresponding capillary values. There was also a trend toward higher venous mean corpuscular volume, higher capillary polymorphonuclear leukocyte (PML) count and mean platelet volume in all groups. In both capillary and venous blood, Hb, Hct, RBC, MCV values and WBC, lymphocyte, PML counts decreased and platelet counts increased steadily during neonatal period. This study reveals that CBC parameters and differential counts may differ depending on the blood sampling used. The findings underline the importance of considering the sample source when using hematologic reference ranges for healthy or septic neonates. When interpreting results, the term ,peripheral blood' should be replaced with ,capillary blood' or ,venous blood' so that an accurate assessment can be made. [source]

    Measurement of pulmonary surfactant disaturated-phosphatidylcholine synthesis in human infants using deuterium incorporation from body water

    JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 7 2005
    Paola E. Cogo
    Abstract The aim of the study was to determine surfactant palmitate disaturated-phosphatidylcholine (DSPC-PA) synthesis in vivo in humans by the incorporation of deuterium from total body water into DSPC-PA under steady state condition. We studied three newborns and one infant (body weight (BW) 4.6 ± 2.9 kg, gestational age 37.5 ± 2 weeks, age 9 ± 9 days) and four preterm newborns (BW 1.3 ± 0.6 kg, gestational age 30.3 ± 2.5 weeks, postnatal age 8.8 ± 9.2 h). All infants were mechanically ventilated during the study and the four preterm infants received exogenous surfactant at the start of the study. We administered 0.44 g 2H2O/kg BW as a bolus intravenously, followed by 0.0125 g 2H2O/kg BW every 6 h to maintain deuterium enrichment at plateau over 2 days. Urine samples and tracheal aspirates (TA) were obtained prior to dosing and every 6 h thereafter. Isotopic enrichment curves of DSPC-PA from sequential TA and urine deuterium enrichments were analyzed by Gas Chromatography-Isotope Ratio,Mass Spectrometry (GC-IRMS) and normalized for Vienna Standard Mean Ocean Water. Enrichment data were used to measure DSPC-PA fractional synthesis rate (FSR) from the linear portion of the DSPC-PA enrichment rise over time, relative to plateau enrichment of urine deuterium. Secretion time (ST) was defined as the time lag between the start of the study and the appearance of DSPC-PA deuterium enrichment in TA. Data were given as mean ± SD. All study infants reached deuterium-steady state in urine. DSPC-PA FSR was 6.5 ± 2.8%/day (range 2.6,10.2). FSR for infants who did not receive exogenous surfactant was 5.7 ± 3.5%/day (range 2.6,9.9%/day) and 7.3 ± 2.1%/day (range 5.1,10.2%/day) in the preterms, whereas DSPC-PA ST was 10 ± 10 h and 31 ± 10 h respectively. Surfactant DSPC-PA synthesis can be measured in humans by the incorporation of deuterium from body water. This study is a simpler and less invasive method compared to previously published methods on surfactant kinetics by means of stable isotopes. Copyright © 2005 John Wiley & Sons, Ltd. [source]

    Airway function in infants treated with inhaled nitric oxide for persistent pulmonary hypertension

    PEDIATRIC PULMONOLOGY, Issue 3 2008
    Aparna U. Hoskote MD
    Abstract Rationale Inhaled nitric oxide (iNO), used for treatment of persistent pulmonary hypertension of newborn (PPHN), is an oxygen free radical with potential for lung injury. Deferring ECMO with iNO in these neonates could potentially have long-term detrimental effects on lung function. We studied respiratory morbidity (defined as occurrence of respiratory infections requiring treatment, episodes of wheezing, and/or need for ongoing medications following discharge) and airway function at 1 year postnatal age in term neonates treated with iNO but not ECMO for PPHN, and compared data from similar infants recruited to the UK ECMO Trial randomized to receive ECMO or conventional management (CM). Methods Maximal expiratory flow at FRC (V'maxFRC) was measured in infants treated with iNO for PPHN (oxygenation index ,25) at birth. Results V'maxFRC was measured in 23 infants and expressed as z -scores, to adjust for sex and body size and compared to data from 71 (46 ECMO, 25 CM) infants studied at a similar age in the ECMO Trial. Respiratory morbidity was low in iNO group. V'maxFRCz -score was lower than predicted in all groups (P,<,0.001), with no significant difference between those treated with iNO [mean (SD) z -score: ,1.65 (1.2)] and those treated with ECMO [,1.59 (1.2)] or CM [,2.1(1.0)]. Within iNO, ECMO and CM groups; 26%, 37% and 56%, respectively, had V'maxFRCz -scores below normal. Conclusions Respiratory outcome at 1 year in iNO treated neonates with moderately severe PPHN is encouraging, with no apparent increase in respiratory morbidity when compared to the general population. Sub-clinical reductions in airway function are evident at 1 year, suggesting that continuing efforts to minimize lung injury in the neonatal period are warranted to maximize lung health in later life. Pediatr Pulmonol. 2008; 43:224,235. © 2008 Wiley-Liss, Inc. [source]

    Effects of fetal growth restriction on lung development before and after birth: A morphometric analysis

    PEDIATRIC PULMONOLOGY, Issue 3 2001
    G.S. Maritz PhD
    Abstract Our aim was to determine the effects of fetal growth restriction (FGR) during late gestation on the structure of the lungs in the fetus near term and at 8 weeks after birth. The studies were performed using two groups of pregnant sheep and their offspring. In both groups, FGR was induced by umbilico-placental embolisation (UPE); for fetal studies, UPE was performed from 120 days of gestation until 140 days (term, ,146 days), when fetuses were killed for tissue analysis. For postnatal studies, UPE continued from 120 days until delivery at term; postnatal lambs were killed at 8 weeks after birth for tissue analysis. UPE led to a thicker pulmonary blood-air barrier at 140 days of gestation and this difference, which was due to a thickened basement membrane, was still present at 8 weeks after birth. At 8 weeks, we also observed a smaller number of alveoli per respiratory unit, thicker interalveolar septa, and a greater volume density of lung tissue in FGR lambs compared to controls. These changes would be expected to impair gas exchange and alter the mechanical properties of the lungs. Our data show that structural alterations in the lungs induced by placental insufficiency were more evident at 8 weeks of postnatal age than near term, indicating that the effects of FGR on the lung may become more serious with age and may affect respiratory health later in life. Pediatr Pulmonol. 2001; 32:201,210. © 2001 Wiley-Liss, Inc. [source]

    Cardiocirculatory effects of patent ductus arteriosus in extremely low-birth-weight infants with respiratory distress syndrome

    PEDIATRICS INTERNATIONAL, Issue 3 2003
    Senji Shimada
    Abstract Background:,Cardiocirculatory effects of hemodynamically significant patent ductus arteriosus (hsPDA) have not been systematically studied in extremely low-birth-weight (ELBW) infants with respiratory distress syndrome (RDS). The objective of the present study was to evaluate the effects of hsPDA on the left ventricular output (LVO) and organ blood flows in ELBW infants with RDS. Methods:,Extremely low-birth-weight infants (birth-weight <1000 g) treated with surfactant for RDS were studied by serial Doppler flow examinations. Doppler flow variables in 19 infants in whom hsPDA developed (hsPDA group) were compared with those in 19 infants without hsPDA matched for gestational age, birth-weight, and postnatal age (non-hsPDA group). All infants in the hsPDA group had pharmacologic closure of ductus arteriosus when hsPDA developed. Results:,Before pharmacological closure of PDA, the hsPDA group had significantly higher LVO, lower blood flow volume of the abdominal aorta, and lower mean blood flow velocities in the celiac artery, superior mesenteric artery, and renal artery than the non-hsPDA group. These alterations in the hsPDA group reverted to the levels in the non-hsPDA group after the closure of PDA and had no deleterious effects on the cardiorespiratory status. No significant differences between the groups were found in mean blood flow velocities of the anterior cerebral artery throughout the study period. Conclusion:,These results indicate that although LVO is increased, the splanchnic and renal blood flows are decreased when hsPDA develops in ELBW infants with RDS. The effects of these alterations of LVO and organ blood flows on the cardiorespiratory course seem to be minor when early pharmacologic closure of PDA is done. [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]

    Spatiotemporal Localization of VEGF-A Isoforms in the Mouse Postnatal Growth Plate

    THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2008
    Kristin D. Evans
    Abstract Vascular endothelial growth factor (VEGF) is implicated as a key angiogenic factor in the development of endochondral long bone. Several studies have evaluated the role of VEGF in prenatal endochondral bone development, but few have evaluated VEGF postnatally. Growth plates from mice at postnatal ages 14 (P14), 35 (P35), 49 (P49), and 77 (P77) days were examined for differential expression of the primary VEGF-A mRNA isoforms: VEGF 120, VEGF 164, and VEGF 188. VEGF 120 isoform expression was stable across all ages, whereas VEGF 164 had significantly less expression at P35 and P49 and VEGF l88 expression increased with increasing age. The proportion of transcript isoforms expressed at a given age also changed with VEGF 120 being expressed more highly at P35 and P49 than the other two isoforms. Changes in VEGF mRNA isoforms across cell types within the growth plate were assessed by Percoll fractionation of growth plate cells at age P28. Cells of the proliferative and early hypertrophic regions had significantly higher total VEGF mRNA expression relative to the resting and late hypertrophic regions. VEGF protein expression assessed by immunohistochemistry showed variable expression patterns with increasing postnatal age. In contrast, FLK-1 (VEGF Receptor-2) expression was restricted to the hypertrophic region. These results indicate that VEGF continues to play a significant role in endochondral bone development throughout the entire growth phase of postnatal bone development. Anat Rec, 291:6,13, 2007. © 2007 Wiley-Liss, Inc. [source]

    Limited predictability of amikacin clearance in extreme premature neonates at birth

    BRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 1 2006
    Karel Allegaert
    Aim Identify and quantify factors describing variability of amikacin clearance in preterm neonates at birth. Methods Population pharmacokinetics of amikacin were estimated in a cohort of 205 extreme preterm neonates [post conception age (PCA) 27.8, SD 1.8, range 24,30 weeks; weight 1.07, SD 0.34, range 0.45,1.98 kg, postnatal age <,72 h]. Covariate analysis included weight, PCA, Apgar score, prophylactic administration of a nonsteroidal anti-inflammatory drug (NSAID) to the neonate, maternal indomethacin and betamethasone administration, and chorioamnionitis. Results A one-compartment linear disposition model with zero order input (0.3 h i.v. infusion) and first-order elimination was used. The population parameter estimate for volume of distribution (V) was 40.2 l per 70 kg. Clearance (CL) increased from 0.486 l h,1 per 70 kg at 24 weeks PCA to 0.940 l h,1 per 70 kg by 30 weeks PCA. The population parameter variability (PPV) for CL and V was 0.336 and 0.451. The use of a NSAID (either aspirin or ibuprofen) in the first day of life reduced amikacin clearance by 22%. Overall 65% of the variability of CL was predictable. Weight explained 48%, PCA 15% and NSAIDs 2%. Conclusions Size and post-conception age are the major contributors to clearance variability in extreme premature neonates (<31 weeks PCA). The large (35% of total) unexplained variability in clearance reinforces the need for target concentration intervention to reduce variability in exposure to a safe and effective range. [source]

    Does caffeine impair cerebral oxygenation and blood flow velocity in preterm infants?

    ACTA PAEDIATRICA, Issue 9 2010
    MB Tracy
    Abstract Aim:, The aim of the study is to assess the effects of an intravenous 10 mg/kg loading dose of caffeine base in cerebral oxygenation, cerebral Doppler blood flow velocity and cardiac output in preterm infants. Methods:, Preterm neonates <34 weeks gestation were investigated at 1 and 4 h following the loading dose of caffeine using Doppler cerebral sonography, cardiac echocardiography and cerebral spatially resolved near-infrared spectroscopy. Results:, Forty infants were studied with a mean gestational age (mean ± standard deviation) of 27.7 (±2.5) weeks, birth weight of 1155 (±431) g and a postnatal age of 2.8 (±2.2) days. Mean Anterior Cerebral Artery peak and time average mean blood flow velocity fell significantly by 14% and 17.7%, respectively at 1 h post-caffeine loading dose, which recovered partially by 4 h. Cerebral Tissue Oxygenation Index fell from pre-dose levels by 9.5% at 1 h with partial recovery to 4.9% reduced at 4 h post-dose. There were no significant changes in left or right ventricular output, transcutaneous oxygen saturation, transcutaneous PCO2 or total vascular resistance. Conclusions:, A loading dose of 10 mg/kg caffeine base resulted in significant reduction at 1 h post-dose in cerebral oxygenation and cerebral blood flow velocity with partial recovery at 4 h. [source]

    Transcutaneous bilirubinometry reduces the need for blood sampling in neonates with visible jaundice

    ACTA PAEDIATRICA, Issue 12 2009
    S Mishra
    Abstract Objectives:, We determined usefulness of transcutaneous bilirubinometry to decrease the need for blood sampling to assay serum total bilirubin (STB) in the management of jaundiced healthy Indian neonates. Methods:, Newborns, ,35 weeks' gestation, with clinical evidence of jaundice were enrolled in an institutional approved randomized clinical trial. The severity of hyperbilirubinaemia was determined by two non-invasive methods: i) protocol-based visual assessment of bilirubin (VaB) and ii) transcutaneous bilirubin (TcB) determination (BiliCheck®). By a random allocation, either method was used to decide the need for blood sampling, which was defined to be present if assessed STB by allocated method exceeded 80% of hour-specific threshold values for phototherapy (2004 AAP Guidelines). Results:, A total of 617 neonates were randomized to either TcB (n = 314) or VaB (n = 303) groups with comparable gestation, birth weight and postnatal age. Need for blood sampling to assay STB was 34% lower (95% CI: 10% to 51%) in the TcB group compared with VaB group (17.5% vs 26.4% assessments; risk difference: ,8.9%, 95% CI: ,2.4% to ,15.4%; p = 0.008). Conclusion:, Routine use of transcutaneous bilirubinometry compared with systematic visual assessment of bilirubin significantly reduced the need for blood sampling to assay STB in jaundiced term and late-preterm neonates. (ClinicalTrials.gov number, NCT00653874) [source]

    Plasma levels of asymmetric dimethylarginine in premature neonates: its possible involvement in developmental programming of chronic diseases

    ACTA PAEDIATRICA, Issue 3 2009
    Gabriella Vida
    Abstract Aim: The endothel dysfunction in early life may play a role in developmental programming of cardiovascular morbidity. The changes of dimethylarginines' plasma levels during the first month among preterm infants and their determinants had been investigated in our study. Methods: Twenty preterm infants of healthy mothers were studied. Mean (±SD) birth weight and gestational age were 919.5 ± 235.5 g and 26.7 ± 1.6 weeks, respectively. Blood samples were taken by venipuncture at the 3rd, 7th, 14th, 21st and 28th days. Plasma concentrations of L-arginine, asymmetric and symmetric dimethylarginine (SDMA) were measured by liquid chromatography-mass spectrometry method, evaluated by multivariate linear regression analysis. Results: L-arginine (p < 0.001) and asymmetric dimethylarginine (ADMA) levels (p < 0.001) were positively associated with postnatal age. ADMA levels were negatively correlated with gestational age (p = 0.007), dopamine-need on the 3rd day of life (p = 0.015) and late infection (p = 0.038). The higher birth weight was associated with higher L-arginine (p = 0.052) and ADMA (p = 0.002) concentrations. The dopamine-need on the 7th day of life had a significant effect on postnatal elevation of SDMA levels (p = 0.035). Conclusion: The progressive increase of ADMA levels described by our study among preterm infants suggests that early endothel dysfunction may take part in developmental programming of chronic adult diseases. [source]

    Clinician observation of physiological trend monitoring to identify late-onset sepsis in preterm infants

    ACTA PAEDIATRICA, Issue 9 2008
    Christopher J Dewhurst
    Abstract Aim: To determine whether trends in routinely collected physiological variables can be used retrospectively to classify infants according to the presence or absence of late-onset neonatal sepsis. Methods: Case control study. Thirty infants born ,32 weeks of gestation who developed late-onset sepsis were matched with 30 controls for gestational and postnatal age but remained sepsis free. For each infant, 25 clinicians inspected 48 h of routine monitoring of heart rate, respiratory rate and oxygen saturation. Clinicians were asked to determine whether the recording was obtained from an infant who did or did not develop sepsis and also indicate how confident they were in their judgement. Clinicians were stratified into three groups by professional role. Results: The median correct assignment of infant's recordings was 67% (IQR 62,72). When very confident, this improved to 82% (IQR 67,88). Overall sensitivity was 53% (IQR 43,63) and specificity 80% (IQR 67,87). Advanced neonatal nurse practitioners consistently assigned babies to the correct group more often than other professional groups. Conclusion: The simple observation physiological trend graphs can classify infants according to the presence or absence of late-onset neonatal sepsis. The accuracy of this method is good to strong but varies with experience of neonatal intensive care. [source]

    Nicotine in breast milk influences heart rate variability in the infant

    ACTA PAEDIATRICA, Issue 8 2008
    Anders Dahlström
    Abstract Aim: To study the effects of postnatal exposure to nicotine on the regulation of heart rate and blood pressure in infants. Subjects and Methods: Thirty-eight mother,infant pairs were studied. Twenty nonsmoking and 18 smoking (2,20 cigarettes per day) mothers were included. All infants were healthy, exclusively breastfed and their postnatal age was 6 weeks. During a home visit infant's urine and mothers' milk were sampled and concentrations of nicotine and cotinine were analyzed. Infants' electrocardiogram (ECG) were recorded, sleep state documented and blood pressure during sleep was measured. Heart rate variability (HRV) was calculated with spectral analysis of R,R intervals. Results: The smoking mothers exposed their infants to nicotine in milk with a median nicotine concentration of 47 (8,192) ,g/L. Analysis of infants' urine showed that the nonsmoking group had 0.8 (0,5.2) and the smoke group 60 (17,139) ,g cotinine/L (p < 0.01). The frequency domain low-to-high frequency (LF/HF) ratio, was correlated to milk nicotine concentrations in the milk sample, from smoking mothers. HRV decreased, with increasing milk nicotine, ingested by the boys (r =,0.74, p = 0.02) but not the girls (r =,0.13, p = 0.76). The differences of mean arterial pressure between sleep states in the infants, were significantly lower in the smoke group 5.8(6.8) compared to the nonsmoke group 11.5(7.2) mmHg (p = 0.03). Conclusions: Postnatal exposure to nicotine influences autonomic cardiovascular control in infants. [source]

    The role of matrix metalloproteinases -9 and -2 in development of neonatal chronic lung disease

    ACTA PAEDIATRICA, Issue 6 2004
    DG Sweet
    Aim: Matrix metalloproteinases (MMPs) -9 and -2 degrade type-IV collagen, a major constituent of lung basement membrane, and may have a role in the pathogenesis of neonatal chronic lung disease (CLD). We determined factors influencing MMP levels in neonatal bronchoalveolar lavage (BAL) fluid to establish whether an imbalance between MMP and its inhibitor could be implicated in CLD. Methods: We measured MMP-9 and -2 and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels in 316 BAL fluid samples from 121 babies of gestational ages 23 to 42 wk over the first 14 d of life to determine effects of gestation and postnatal age. Median MMP-9, -2, TIMP-1 and MMP-9/TIMP-1 ratio in BAL were further studied in a subgroup of 85 babies >33 wk gestation to determine their ability to predict CLD and to establish effects of antenatal corticosteroid therapy (ANCS). Results: MMP-9, -2 and TIMP levels did not vary with postnatal age over the first week. Median MMP-9 levels and MMP-9/TIMP-1 ratio increased with decreasing gestation in preterm babies. The MMP-9/TIMP-1 ratio was higher in babies who developed CLD, implying a proteinase/antiproteinase imbalance, but this association disappeared when controlled for gestational age. ANCS had no effect on BAL fluid MMP or TIMP levels. Conclusion: MMPs may have a role in the development of lung injury and fibrosis, but estimating their levels in the first week of life does not help with prediction of CLD. [source]

    Late-onset neutropenia in very low birthweight infants

    ACTA PAEDIATRICA, Issue 2002
    G Chirico
    Aim: To evaluate the incidence and duration of late-onset neutropenia (defined as an absolute neutrophil count (ANC) <1500 mm,3 at a postnatal age of >3 wk) in a population of infants with birthweight <2000 g, and to determine whether copper deficiency, a possible cause of both anemia and neutropenia, may be associated with this complication. Methods: Complete blood cell count and differential were assessed in 247 low (LBW) and very low birthweight (VLBW) infants who were discharged after 3 wk of life. In neutropenic infants plasma copper and ceruloplasmin levels were also measured. Results: Late-onset neutropenia was detected in 11 out of 147 VLBW infants (7.5%) and in 7 out of 127 LBW infants (5.5%). A neutrophil count of <1000 mm,3 was observed in 14 infants (5.1%). A significantly lower gestational age was found in neutropenic infants compared with non-neutropenic infants. In neutropenic infants ANCs were significantly correlated with hemoglobin and hematocrit. In addition, a significant negative correlation was found between neutrophil and reticulocyte counts. Plasma copper concentration was significantly correlated with birthweight. Oral copper sulfate was administered to infants with plasma copper concentration <50 ,g dl,1, and did not seem to affect ANC, hemoglobin, hematocrit or reticulocyte counts. Conclusion: Late-onset neutropenia appears to be a benign condition that is not associated with any particular complication and does not require specific treatment. Reference ranges after the early neonatal period and during the first few months of life in LBW and VLBW infants should probably be set at lower values. [source]

    Changes in serum leptin concentration after corticosteroid treatment in preterm infants

    ACTA PAEDIATRICA, Issue 6 2002
    PC Ng
    The aim of this study was to investigate the effect of postnatal systemic dexamethasone on serum leptin, insulin and hormones of the hypothalamic-pituitary-adrenal (HPA) axis in preterm, very low birthweight (VLBW) infants. Nineteen VLBW infants who received a 3 wk dose tapering course of dexamethasone for treatment of bronchopulmonary dysplasia were prospectively enrolled. Blood for hormone assays was collected immediately before the start of the dexamethasone course (Td-pre), 3 wk after commencement of the drug (Td-end) and 2 wk after dexamethasone treatment had been stopped (Td-post). In addition, 28 VLBW infants who participated in a concurrent longitudinal leptin study within the same period but did not receive corticosteroid had their serum leptin and insulin concentrations serially monitored. Blood specimens for the latter group of infants were obtained at 2 (Twk,2), 5 (Twk,5) and 7 (Twk,7) wk of postnatal age. Serum leptin and insulin at Td,end were significantly increased, whereas plasma ACTH and serum cortisol were significantly suppressed compared with the pretreatment (Td,pre) levels in the corticosteroid group (p > 0.0001 for leptin and insulin; p > 0.05 and p > 0.001 for ACTH and cortisol, respectively). In contrast, serum leptin and insulin at weeks 5 (Twk,5) and 7 (Twk,7) did not differ significantly from their respective levels at week 2 (Twk,2) in the non-treatment group. Conclusion: The administration of systemic corticosteroid resulted in significant increases in serum leptin and insulin, but marked suppression of hormones of the HPA axis. The effect of dexamethasone on the "adipoinsular" and HPA axes was transient and reversible. The adipoinsular axis in preterm infants is likely to be functional and active at an early stage of human development, and leptin may regulate energy balance in VLBW infants in the early postnatal period. Corticosteroids may, through the adipoinsular axis or its associated pathways, mediate in the regulation of body weight in preterm neonates. [source]

    Cerebellar granule cells show age-dependent migratory differences in vitro

    DEVELOPMENTAL NEUROBIOLOGY, Issue 2 2005
    Krisztián Tárnok
    Abstract Developmental differences between cerebellar granule cells during their migratory period were revealed using dissociated granule cell cultures isolated from 4, 7, or 10 days old (P4, P7, P10) mice. Under all culture conditions, the great majority of cultivated cell populations consisted of those granule cells that had not reach their final destination in the internal granule cell layer (IGL) by the age of isolation. In vitro morphological development and the expression of migratory markers (TAG-1, astrotactin, or EphB2) showed similar characteristics between the cultures. The migration of 1008 granule cells isolated from P4, P7, and P10 cerebella and cultivated under identical conditions were analyzed using statistical methods. In vitro time-lapse videomicroscopy revealed that P4 cells possessed the fastest migratory speed while P10 granule cells retained their migratory activity for the longest time in culture. Cultures obtained from younger postnatal ages showed more random migratory trajectories than P10 cultures. Our observations indicate that despite similar morphological and molecular properties, migratory differences exist in granule cell cultures isolated from different postnatal ages. Therefore, the age of investigation can substantially influence experimental results on the regulation of cell migration. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005 [source]

    Quantitative analysis of postnatal neurogenesis and neuron number in the macaque monkey dentate gyrus

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2010
    Adeline Jabčs
    Abstract The dentate gyrus is one of only two regions of the mammalian brain where substantial neurogenesis occurs postnatally. However, detailed quantitative information about the postnatal structural maturation of the primate dentate gyrus is meager. We performed design-based, stereological studies of neuron number and size, and volume of the dentate gyrus layers in rhesus macaque monkeys (Macaca mulatta) of different postnatal ages. We found that about 40% of the total number of granule cells observed in mature 5,10-year-old macaque monkeys are added to the granule cell layer postnatally; 25% of these neurons are added within the first three postnatal months. Accordingly, cell proliferation and neurogenesis within the dentate gyrus peak within the first 3 months after birth and remain at an intermediate level between 3 months and at least 1 year of age. Although granule cell bodies undergo their largest increase in size during the first year of life, cell size and the volume of the three layers of the dentate gyrus (i.e. the molecular, granule cell and polymorphic layers) continue to increase beyond 1 year of age. Moreover, the different layers of the dentate gyrus exhibit distinct volumetric changes during postnatal development. Finally, we observe significant levels of cell proliferation, neurogenesis and cell death in the context of an overall stable number of granule cells in mature 5,10-year-old monkeys. These data identify an extended developmental period during which neurogenesis might be modulated to significantly impact the structure and function of the dentate gyrus in adulthood. [source]

    Differential expression of PKC beta II in the rat organ of Corti

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2007
    S. Ladrech
    Abstract To investigate a possible involvement of protein kinase C (PKC) in cochlear efferent neurotransmission, we studied the expression of the calcium-dependent PKC beta II isoform in the rat organ of Corti at different postnatal ages using immunofluorescence and immunoelectron microscopy. We found evidence of PKC beta II as early as postnatal day (PND) 5 in efferent axons running in the inner spiral bundle and in Hensen cells. At PND 8, we also found PKC beta II in efferents targeting outer hair cells (OHCs), and a slight detection at the synaptic pole in the first row of the basal and middle cochlear turns. At PND 12, PKC beta II expression declined in the efferent fibres contacting OHCs, whereas expression was concentrated at the postsynaptic membrane, from the basal and middle turns. The adult-like pattern of PKC beta II distribution was observed at PND 20. Throughout the cochlea, we found PKC beta II expression in the Hensen cells, non-sensory cells involved in potassium re-cycling, and lateral efferent terminals of the inner spiral bundle. In addition, we observed expression in OHCs at the postsynaptic membrane facing the endings of the medial efferent system, with the exception of some OHCs located in the most apical region of the cochlea. These data therefore suggest an involvement of PKC beta II in both cochlear efferent neurotransmission and ion homeostasis. Among other functions, PKC beta II could play a role in the efferent control of OHC activity. [source]

    Regional and Developmental Expression of the Npc1 mRNA in the Mouse Brain

    JOURNAL OF NEUROCHEMISTRY, Issue 3 2000
    A. Prasad
    Abstract: Niemann-Pick type C (NP-C) disease is a fatal, autosomal recessive disorder of cholesterol metabolism that results in progressive central nervous system deterioration and premature death. Recently, a gene mutated in NP-C disease (NPC1) was identified in both human patients and in the npcnih mouse model. Although the function of the NPC1 gene is at present unknown, determining the pattern of its expression in the brain may facilitate identification of the mechanisms underlying the neuropathology of this disease and in identifying relevant targets for any potential therapeutic intervention. We have used in situ hybridization techniques to characterize the pattern of Npc1 mRNA expression in both the wild-type and the npcnih mutant mouse brain. In adult animals of both genotypes, the Npc1 mRNA was detected in the majority of neurons in nearly all regions, but at significantly higher levels in the cerebellum and in specific pontine nuclei. Analysis of Npc1 mRNA levels during development in the wild-type mouse indicated that this transcript was expressed in neurons as early as embryonic day 15 and that a significant region-specific pattern of expression was established by postnatal day 7. Our data suggest that whereas the NPC1 gene is widely expressed in neurons of the brain, the higher levels of expression in the cerebellum and pontine structures established by early postnatal ages may make these regions more susceptible to neuronal dysfunction in NP-C disease. [source]

    Thyroid hormone stimulates ,-glutamyl transpeptidase in the developing rat cerebra and in astroglial cultures

    JOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2005
    Asmita Dasgupta
    Abstract Hypothyroidism in the developing rat brain is associated with enhanced oxidative stress, one of the earliest manifestations of which is a decline in the level of glutathione (GSH). To investigate the role of thyroid hormone (TH) on GSH homeostasis, the effect of TH on ,-glutamyl transpeptidase (,GT), the key enzyme involved in the catalysis of GSH, was studied. Hypothyroidism declined the specific activity of cerebral ,GT at all postnatal ages examined (postnatal day 1,20) with a maximum inhibition of 42% at postnatal day 10. Intraperitoneal injection of TH to 15-day-old rat pups increased the specific activity of ,GT by 25-30% within 4,6 hr. Treatment of primary cultures of astrocytes by TH also enhanced the specific activity of ,GT by 30,40% within 4,6 hr. The induction of ,GT by TH was blocked by actinomycin D or cycloheximide. ,GT is an ectoenzyme that is normally involved in the catabolism of GSH released by astrocytes. In the presence of the ,GT-inhibitor, acivicin, GSH released in the culture medium of astrocytes increased linearly for at least 6 hr and TH had no effect on this accumulation pattern. In the absence of acivicin, GSH content of the medium from TH-treated cells was significantly lower than that of untreated controls due to activation of ,GT by TH and a faster processing of GSH. Because the products of ,GT reaction are putative precursors for neuronal GSH, the activation of ,GT by TH may be conducive to GSH synthesis in neurons and their protection from oxidative stress. © 2005 Wiley-Liss, Inc. [source]

    Short-Term Antiandrogen Flutamide Treatment Causes Structural Alterations in Somatic Cells Associated with Premature Detachment of Spermatids in the Testis of Pubertal and Adult Guinea Pigs

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2010
    LR Maschio
    Contents In spite of widespread application of flutamide in the endocrine therapies of young and adult patients, the side effects of this antiandrogen on spermatogenesis and germ-cell morphology remain unclear. This study evaluates the short-term androgen blockage effect induced by the administration of flutamide to the testes of pubertal (30-day old) and adult (65- and 135-day old) guinea pigs, with an emphasis on ultrastructural alterations of main cell types. The testes removed after 10 days of treatment with either a non-steroidal antiandrogen, flutamide (10 mg/kg of body weight) or a pharmacological vehicle alone were processed for histological, quantitative and ultrastructural analysis. In pubertal animals, flutamide androgenic blockage induces spermatogonial differentiation and accelerates testes maturation, causing degeneration and detachment of primary spermatocytes and round spermatids, which are subsequently found in great quantities in the epididymis caput. In post-pubertal and adult guinea pigs, in addition to causing germ-cell degeneration, especially in primary spermatocytes, and leading to the premature detachment of spherical spermatids, the antiandrogen treatment increased the relative volume of Leydig cells. In addition, ultrastructural evaluation indicated that irrespective of age antiandrogen treatment causes an increase in frequency of organelles involved with steroid hormone synthesis in the Leydig cells and a dramatic accumulation of myelin figures in their cytoplasm and, to a larger degree, in Sertoli cells. In conclusion, the transient exposition of the guinea pigs to flutamide, at all postnatal ages causes some degenerative lesions including severe premature detachment of spermatids and accumulation of myelin bodies in Leydig and Sertoli cells, compromising, at least temporarily, the spermatogenesis. [source]

    Spatiotemporal Localization of VEGF-A Isoforms in the Mouse Postnatal Growth Plate

    THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2008
    Kristin D. Evans
    Abstract Vascular endothelial growth factor (VEGF) is implicated as a key angiogenic factor in the development of endochondral long bone. Several studies have evaluated the role of VEGF in prenatal endochondral bone development, but few have evaluated VEGF postnatally. Growth plates from mice at postnatal ages 14 (P14), 35 (P35), 49 (P49), and 77 (P77) days were examined for differential expression of the primary VEGF-A mRNA isoforms: VEGF 120, VEGF 164, and VEGF 188. VEGF 120 isoform expression was stable across all ages, whereas VEGF 164 had significantly less expression at P35 and P49 and VEGF l88 expression increased with increasing age. The proportion of transcript isoforms expressed at a given age also changed with VEGF 120 being expressed more highly at P35 and P49 than the other two isoforms. Changes in VEGF mRNA isoforms across cell types within the growth plate were assessed by Percoll fractionation of growth plate cells at age P28. Cells of the proliferative and early hypertrophic regions had significantly higher total VEGF mRNA expression relative to the resting and late hypertrophic regions. VEGF protein expression assessed by immunohistochemistry showed variable expression patterns with increasing postnatal age. In contrast, FLK-1 (VEGF Receptor-2) expression was restricted to the hypertrophic region. These results indicate that VEGF continues to play a significant role in endochondral bone development throughout the entire growth phase of postnatal bone development. Anat Rec, 291:6,13, 2007. © 2007 Wiley-Liss, Inc. [source]

    Learning to breathe: control of the inspiratory,expiratory phase transition shifts from sensory- to central-dominated during postnatal development in rats

    THE JOURNAL OF PHYSIOLOGY, Issue 20 2009
    Mathias Dutschmann
    The hallmark of the dynamic regulation of the transitions between inspiration and expiration is the timing of the inspiratory off-switch (IOS) mechanisms. IOS is mediated by pulmonary vagal afferent feedback (Breuer,Hering reflex) and by central interactions involving the Kölliker,Fuse nuclei (KFn). We hypothesized that the balance between these two mechanisms controlling IOS may change during postnatal development. We tested this hypothesis by comparing neural responses to repetitive rhythmic vagal stimulation, at a stimulation frequency that paces baseline breathing, using in situ perfused brainstem preparations of rats at different postnatal ages. At ages < P15 (P, postnatal days), phrenic nerve activity (PNA) was immediately paced and entrained to the afferent input and this pattern remained unchanged by repetitive stimulations, indicating that vagal input stereotypically dominated the control of IOS. In contrast, PNA entrainment at > P15 was initially insignificant, but increased after repetitive vagal stimulation or lung inflation. This progressive adaption of PNA to the pattern of the sensory input was accompanied by the emergence of anticipatory centrally mediated IOS preceding the stimulus trains. The anticipatory IOS was blocked by bilateral microinjections of NMDA receptor antagonists into the KFn and PNA was immediately paced and entrained, as it was seen at ages < P15. We conclude that as postnatal maturation advances, synaptic mechanisms involving NMDA receptors in the KFn can override the vagally evoked IOS after ,training' using repetitive stimulation trials. The anticipatory IOS may imply a hitherto undescribed form of pattern learning and recall in convergent sensory and central synaptic pathways that mediate IOS. [source]

    Postnatal changes in the expression of genes located in the callipyge region in sheep skeletal muscle

    ANIMAL GENETICS, Issue 6 2006
    A. C. Perkins
    Summary The expression of five genes surrounding the callipyge (CLPG) mutation was analysed in skeletal muscles from lambs at one prenatal and two postnatal ages that coincide with the onset and establishment of muscle hypertrophy. Genotype-specific changes in transcript abundance were detected for paternal allele-specific DLK1 and PEG11 (the official symbol of the latter is RTL1) and the maternal allele-specific MEG3, PEG11AS and MEG8 when the mutation was inherited in cis. There were differences in the temporal and muscle-specific effects on expression between the maternal allele-specific genes and paternal allele-specific genes. Maternal inheritance of the CLPG allele had a significant effect on the expression of MEG3 and MEG8 at prenatal and postnatal ages, whereas paternal inheritance of DLK1 and PEG11 only affected postnatal expression. Genotype-specific changes in PEG11AS expression were detected only in prenatal muscle. Maternal inheritance of the mutation caused similar changes in MEG3 and MEG8 expression in the semimembranosus, which undergoes hypertrophy, and the supraspinatus, which does not hypertrophy. Paternal inheritance of the mutation caused changes in PEG11 expression in both muscles, although the magnitude of expression in semimembranosus was more than 100-fold greater than in supraspinatus. DLK1 expression was upregulated in callipyge animals at both postnatal ages in the semimembranosus, but there was no effect of genotype on DLK1 expression in the supraspinatus at any age. Increased DLK1 expression was likely the primary cause of muscle hypertrophy, but a contribution of PEG11 to the phenotype cannot be ruled out based on gene expression. [source]

    Depletion of the neural precursor cell pool by glucocorticoids

    ANNALS OF NEUROLOGY, Issue 1 2010
    Shuang Yu MD
    Objective Glucocorticoids (GCs) are indicated for a number of conditions in obstetrics and perinatal medicine; however, the neurodevelopmental and long-term neurological consequences of early-life GC exposure are still largely unknown. Preclinical studies have demonstrated that GCs have a major influence on hippocampal cell turnover by inhibiting neurogenesis and stimulating apoptosis of mature neurons. Here we examined the fate of the limited pool of neural progenitor cells (NPCs) after GC administration during neonatal development; the impact of this treatment on hippocampal structure was also studied. Methods Phenotype-specific genetic and antigenic markers were used to identify cultured NPCs at various developmental stages; the survival of these cells was monitored after exposure to the synthetic glucocorticoid dexamethasone (DEX). In addition, the effects of neonatal DEX treatment on the neurogenic potential of the rat hippocampus were examined by monitoring the incorporation of bromodeoxyuridine and expression of Ki67 antigen at various postnatal ages. Results Multipotent nestin-expressing NPCs and T,1-tubulin,expressing immature neurons succumb to GC-induced apoptosis in primary hippocampal cultures. Neonatal GC treatment results in marked apoptosis among the proliferating population of cells in the dentate gyrus, depletes the NPC pool, and leads to significant and sustained reductions in the volume of the dentate gyrus. Interpretation Both NPCs and immature neurons in the hippocampus are sensitive to the proapoptotic actions of GCs. Depletion of the limited NPC pool during early life retards hippocampal growth, thus allowing predictions about the potential neurological and psychiatric consequences of neonatal GC exposure. ANN NEUROL 2010;67:21,30 [source]