Transition from dynamically maintained to relaxed end-expiratory volume in human infants

1989 ◽  
Vol 67 (5) ◽  
pp. 2107-2111 ◽  
Author(s):  
A. A. Colin ◽  
M. E. Wohl ◽  
J. Mead ◽  
F. A. Ratjen ◽  
G. Glass ◽  
...  

Newborn infants, in contrast to adults, dynamically maintain end-expiratory lung volume (EEV) above relaxation volume. The purpose of this study was to determine at what age children develop a breathing strategy that is relaxed, i.e., determined by the mechanical characteristics of the lung and chest wall. Forty studies were performed in 27 healthy infants and children aged 1 mo to 8 yr during natural sleep. Volume changes were recorded with the use of respiratory inductance plethysmography (RIP). The volume signal was differentiated to yield flow. Flow-volume representations were generated for a random sample of the recorded breaths to determine the predominant breathing strategy utilized, i.e., relaxed, interrupted, or indeterminate. The respiratory pattern was predominantly interrupted below 6 mo of age and predominantly relaxed over 1 yr of age. Mixed patterns were observed in children 6-12 mo of age. The number of breaths that could not be classified (indeterminate) decreased with age. Respiratory frequency measured from the sample of breaths decreased with age and was accompanied by an increase in expiratory time. We conclude that a relaxed EEV develops at the end of the first year of life and may be related to changes in the mechanical properties of the chest wall associated with growth as well as changes in respiratory timing.

2005 ◽  
Vol 17 (3) ◽  
Author(s):  
Jennifer L. Kirchherr ◽  
George H. Bowden ◽  
Dorothy A. Richmond ◽  
Michael J. Sheridan ◽  
Katherine A. Wirth ◽  
...  

2012 ◽  
Vol 25 (0) ◽  
pp. 200
Author(s):  
David J. Lewkowicz

Human infancy is a time of rapid neural and behavioral development and multisensory perceptual skills emerge during this time. Both animal and human early deprivation studies have shown that experience contributes critically to the development of multisensory perception. Unfortunately, Bodison because the human deprivation studies have only studied adult responsiveness, little is known about the more immediate effects of early experience on multisensory development. Consequently, we have embarked on a program of research to investigate how early experience affects the development of multisensory perception in human infants. To do so, we have focused on multisensory perceptual narrowing, an experience-dependent process where initially broad perceptual tuning is narrowed to match the infant’s native environment. In this talk, I first review our work demonstrating that multisensory narrowing characterizes infants’ response to non-native (i.e., monkey) faces and voices, that the initially broad tuning is present at birth, that narrowing also occurs in the audiovisual speech domain, and that multisensory narrowing is an evolutionarily novel process. In the second part of the talk, I present findings from our most recent studies indicating that experience has a seemingly paradoxical effect on infant response to audio–visual synchrony, that experience narrows infant response to amodal language and intonational prosody cues, and that experience interacts with developmental changes in selective attention during the first year of life resulting in dramatic developmental shifts in human infants’ selective attention to the eyes and mouth of their interlocutors’ talking faces.


PEDIATRICS ◽  
1963 ◽  
Vol 32 (4) ◽  
pp. 497-500
Author(s):  
Rosa Lee Nemir ◽  
Donna O'Hare ◽  
Stanley Goldstein ◽  
Charles B. Hilton

Complement fixing antibody titers to the adenoviruses were determined in 251 newborn infants, using cord blood. Approximately 95% of these were found to have CF titers of 1:16 or over, the majority (75%) were 1:32 or more. Material from the pharyngeal and rectal swabs of these infants on tissue culture studies (542) on HeLa and amnion cells showed no cytopathic effect in oven 96% of these infants. A longitudinal study of 114 of these infants was made at 3 months intervals; 67 have been observed for one year. At 3 months, only 12% still showed CF antibody titers, and these were chiefly at a low level, 1:16. At the subsequent 3-month interval observations, a gradual rise in CF antibodies were found. At one year of age, approximately 37% had titers of 1:32 on over. The findings of this report support the statement that CF antibodies to adenovirus pass the placental barrier. There is a gradual increase in the percentage of infants with positive CF antibodies after 3 months.


PEDIATRICS ◽  
1968 ◽  
Vol 41 (5) ◽  
pp. 945-954
Author(s):  
Fernando Torres ◽  
Michael E. Blaw

One hundred-thirty children who had an EEG during their first days of life and who were registered in a clinical longitudinal study were followed with concurrent clinical and EEG examinations every 4 months for the first year of life and at 2, 3, and 4 years of age. Thirty children had EEG characteristics which are frequently considered abnormal in their neonatal record. Twenty-three children had clinical abnormalities during the 4-year period covered by the study. There was no significant correlation between a single EEG and clinical abnormalities at any age. Newborn infants with more than one focal abnormality in their EEG presented clinical abnormalities more frequently than those with a single focus. The difference, however, did not attain statistical significance. Children with an abnormal EEG at birth and an additional abnormal record later, had a higher incidence of clinical abnormalities than those with only an abnormal neonatal EEG. However, this finding is of questionable significance because the children who had clinical abnormalities had a larger number of EEG's than the normal subjects. It is expected that continued follow-up of these children at more advanced stages of their development may give a positive EEG-clinical correlation which was not found in this study.


1998 ◽  
Vol 85 (6) ◽  
pp. 2033-2039 ◽  
Author(s):  
Patricia S. Rabbette ◽  
Janet Stocks

Both end-inspiratory (EIO) and end-expiratory (EEO) airway occlusions are used to calculate the strength of the Hering-Breuer inflation reflex (HBIR) in infants. However, the influence of the timing of such occlusions is unknown, as is the extent to which changes in volume within and above the tidal range affect this reflex. The purpose of this study was to compare both techniques and to evaluate the volume dependency of the HBIR in healthy, sleeping infants up to 1 yr of age. The strength of the HBIR was expressed as the ratio of expiratory or inspiratory time during EIO or EEO, respectively, to that recorded during spontaneous breathing, i.e., as the “inhibitory ratio” (IR). Paired measurements of the EIO and EEO in 26 naturally sleeping newborn and 15 lightly sedated infants at ∼1 yr showed no statistically significant differences in the IR according to technique: mean (95% CI) of the difference (EIO − EEO) being −0.02 (−0.17, 0.13) during the first week of life and 0.04 (−0.14, 0.22) at 1 yr. During tidal breathing, a volume threshold of ∼4 ml/kg was required to evoke the HBIR. Marked volume and age dependency were observed. In newborn infants, occlusions at ∼10 ml/kg during sighs always resulted in an IR > 4, whereas a similar response was only evoked at 25 ml/kg in older infants. Age-related changes in the volume threshold may reflect maturational changes in the control of breathing and respiratory mechanics throughout the first year of life.


2020 ◽  
Vol 225 (3) ◽  
pp. 1169-1183 ◽  
Author(s):  
Mostafa Jannesari ◽  
Alireza Saeedi ◽  
Marzieh Zare ◽  
Silvia Ortiz-Mantilla ◽  
Dietmar Plenz ◽  
...  

2011 ◽  
Vol 89 (4) ◽  
pp. 312-317 ◽  
Author(s):  
Gianvincenzo Zuccotti ◽  
Alessandra Viganò ◽  
Laura Cafarelli ◽  
Valentina Pivetti ◽  
Laura Pogliani ◽  
...  

1989 ◽  
Vol 67 (3) ◽  
pp. 1192-1197 ◽  
Author(s):  
F. Ratjen ◽  
R. Zinman ◽  
A. R. Stark ◽  
L. E. Leszczynski ◽  
M. E. Wohl

Total respiratory system compliance (Crs) at volumes above the tidal volume (VT) was studied by use of the expiratory volume clamping (EVC) technique in 10 healthy sleeping unsedated newborn infants. Flow was measured with a pneumotachograph attached to a face mask and integrated to yield volume. Volume changes were confirmed by respiratory inductance plethysmography. Crs measured by EVC was compared with Crs during tidal breathing determined by the passive flow-volume (PFV) technique. Volume increases of approximately 75% VT were achieved with three to eight inspiratory efforts during expiratory occlusions. Crs above VT was consistently greater than during tidal breathing (P less than 0.0005). This increase in Crs likely reflects recruitment of lung units that are closed or atelectatic in the VT range. Within the VT range, Crs measured by PFV was compared with that obtained by the multiple-occlusion method (MO). PFV yielded greater values of Crs than MO (P less than 0.01). This may be due to braking of expiratory airflow after the release of an occlusion or nonlinearity of Crs. Thus both volume recruitment and airflow retardation may affect the measurement of Crs in unsedated newborn infants.


2018 ◽  
Vol 13 (4) ◽  
pp. 33-40
Author(s):  
T.B. Sentsova ◽  
◽  
A.N. Ni ◽  
S.M. Kolesnikova ◽  
T.G. Malanicheva ◽  
...  

2010 ◽  
Vol 7 (1) ◽  
pp. 136-138 ◽  
Author(s):  
David W. Haley ◽  
Jennifer Cordick ◽  
Sarah Mackrell ◽  
Immaculate Antony ◽  
Maireanne Ryan-Harrison

In humans, anticipatory stress involves activation of the limbic–hypothalamic–pituitary–adrenal axis, which releases stress hormones such as cortisol in response to an impending stressor. Conditioning of the stress response to anticipate and prepare for future challenges is a hallmark of adaptation. It is unknown whether human infants in the first year of life have developed the neural circuitry to support the anticipation of stressful events in an attachment context. Here, we show that human infants at six months of age produce an anticipatory stress response, as indicated by the release of stress hormones, when re-exposed after 24 h to a context in which they demonstrated a stress response to a disruption in the parent–infant relationship. Although infant stress response (cortisol elevation) was greater to the stressful event (parent unresponsiveness) than to the second exposure to the stress context (room, chair, presence of parent and experimenter, etc.), it was greater in the stress group than in the control group on both days. Results suggest that human infants have the capacity to produce an anticipatory stress response that is based on expectations about how their parents will treat them in a specific context.


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