TY  - JOUR
A1  - Ritz, Thomas
A1  - Enlow, Michelle Bosquet
A1  - Schulz, Stefan M.
A1  - Kitts, Robert
A1  - Staudenmayer, John
A1  - Wright, Rosalind J.
T1  - Respiratory Sinus Arrhythmia as an Index of Vagal Activity during Stress in Infants: Respiratory Influences and Their Control
JF  - PLoS One
N2  - Respiratory sinus arrhythmia (RSA) is related to cardiac vagal outflow and the respiratory pattern. Prior infant studies have not systematically examined respiration rate and tidal volume influences on infant RSA or the extent to which infants' breathing is too fast to extract a valid RSA. We therefore monitored cardiac activity, respiration, and physical activity in 23 six-month old infants during a standardized laboratory stressor protocol. On average, 12.6% (range 0-58.2%) of analyzed breaths were too short for RSA extraction. Higher respiration rate was associated with lower RSA amplitude in most infants, and lower tidal volume was associated with lower RSA amplitude in some infants. RSA amplitude corrected for respiration rate and tidal volume influences showed theoretically expected strong reductions during stress, whereas performance of uncorrected RSA was less consistent. We conclude that stress-induced changes of peak-valley RSA and effects of variations in breathing patterns on RSA can be determined for a representative percentage of infant breaths. As expected, breathing substantially affects infant RSA and needs to be considered in studies of infant psychophysiology.
KW  - responses
KW  - heart-rate-variability
KW  - pulmonary gas-exchange
KW  - still-face
KW  - baroreflex mechanism
KW  - period variability
KW  - preterm infants
KW  - waking states
KW  - reactivity
KW  - attention
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135396
VL  - 7
IS  - 12
ER  - 
TY  - JOUR
A1  - Masic, Anita
A1  - Hurdayal, Ramona
A1  - Nieuwenhuizen, Natalie E.
A1  - Brombacher, Frank
A1  - Moll, Heidrun
T1  - Dendritic Cell-Mediated Vaccination Relies on Interleukin-4 Receptor Signaling to Avoid Tissue Damage after Leishmania major Infection of BALB/c Mice
JF  - PLoS Neglected Tropical Diseases
N2  - Prevention of tissue damages at the site of Leishmania major inoculation can be achieved if the BALB/c mice are systemically given L. major antigen (LmAg)-loaded bone marrow-derived dendritic cells (DC) that had been exposed to CpG-containing oligodeoxynucleotides (CpG ODN). As previous studies allowed establishing that interleukin-4 (IL-4) is involved in the redirection of the immune response towards a type 1 profile, we were interested in further exploring the role of IL-4. Thus, wild-type (wt) BALB/c mice or DC-specific IL-4 receptor \(\alpha\) (IL-4R \(\alpha\))-deficient (CD11c\(^{cre}\)IL-4R \(\alpha^{-/lox}\) BALB/c mice were given either wt or IL-4R \(\alpha\)-deficient LmAg-loaded bone marrow-derived DC exposed or not to CpG ODN prior to inoculation of 2x10\(^5\) stationary-phase L. major promastigotes into the BALB/c footpad. The results provide evidence that IL4/IL-4R alpha-mediated signaling in the vaccinating DC is required to prevent tissue damage at the site of L. major inoculation, as properly conditioned wt DC but not IL-4R alpha-deficient DC were able to confer resistance. Furthermore, uncontrolled L. major population size expansion was observed in the footpad and the footpad draining lymph nodes of CD11c\(^{cre}\)IL-4R \(\alpha^{-/lox}\) mice immunized with CpG ODN-exposed LmAg-loaded IL-4R \(\alpha\)-deficient DC, indicating the influence of IL-4R \(\alpha\)-mediated signaling in host DC to control parasite replication. In addition, no footpad damage occurred in BALB/c mice that were systemically immunized with LmAg-loaded wt DC doubly exposed to CpG ODN and recombinant IL-4. We discuss these findings and suggest that the IL4/IL4R \(\alpha\) signaling pathway could be a key pathway to trigger when designing vaccines aimed to prevent damaging processes in tissues hosting intracellular microorganisms.
KW  - cytokines
KW  - necrosis-factor-alpha
KW  - T helper cell
KW  - visceral leishmaniasis
KW  - intracellular pathogen
KW  - interferon-gamma
KW  - IL-12 production
KW  - deficient mice
KW  - resistance
KW  - responses
Y1  - 2012
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133869
VL  - 6
IS  - 7
ER  -