摘要:

The expression of receptors for several cytokines (IL 2, IL-4, IL-6, IL-7, tumor necrosis factor, and interferon-γ) was examined in human cord blood cells in comparison with adult blood cells. A previously described high sensitivity immunofluorescence procedure was used to render the low levels of receptor measurable. Cord blood lymphocytes expressed measurable levels of most cytokine receptors, but expression tended to be lower than in adult blood cells. Examination of different lymphocyte subpopulations revealed a complex pattern with some cell types expressing particular receptors equivalent to adult levels. Cord and adult blood monocytes expressed similar cytokine receptor profiles. Receptor expression in cord lymphocytes could be regulated by activation. The results provide indications as to the relative activities of different cytokines in the development of the immune system in the neonate.

ISSN:0031-3998    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Immunologic effects of pre- and postnatal polychlorinated biphenyl (PCB)/dioxin exposure in Dutch infants from birth to 18 mo of age are explored. The total study group consisted of 207 healthy mother-infant pairs, of which 105 infants were breast-fed and 102 children were bottle-fed. Prenatal PCB exposure was estimated by the PCB sum (PCB congeners 118, 138, 153, and 180) in maternal blood and the total toxic equivalent (TEQ) level in human milk (17 dioxin and 8 dioxin-like PCB congeners). Postnatal PCB/dioxin exposure was calculated as a product of the total TEQ level in human milk multiplied by the weeks of breast-feeding. The number of periods with rhinitis, bronchitis, tonsillitis, and otitis during the first 18 mo of life was used as an estimate of the health status of the infants. Humoral immunity was measured at 18 mo of age by detecting antibody levels to mumps, measles, and rubella. White blood cell counts (monocytes, granulocytes, and lymphocytes) and immunologic marker analyses CD4+T-lymphocytes, CD8+T-lymphocytes, activated T-lymphocytes (HLA-DR+CD3+), as well as T cell receptor (TcR) αβ+, TcRγδ+, CD4+CD45RA+and CD4+CD45RO+T-lymphocytes, B-lymphocytes (CD19+and/or CD20+) and NK cells (CD16+and/or CD56+/CD3−) in cord blood and venous blood at 3 and 18 mo of age were assessed in a subgroup of 55 infants. There was no relationship between pre-and postnatal PCB/dioxin exposure and upper or lower respiratory tract symptoms or humoral antibody production. A higher prenatal PCB/ dioxin exposure was associated with an increase in the number of TcRγδ+T cells at birth and with an increase in the total number of T cells and the number of CD8+(cytotoxic), TcRαβ+, and TcRγδ+T cells at 18 mo of age. A higher prenatal as well as postnatal PCB/dioxin exposure was associated with lower monocyte and granulocyte counts at 3 mo of age. In conclusion, our study suggests that background levels of PCB/dioxin exposure influences the human fetal and neonatal immune system.

ISSN:0031-3998    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

Body composition data are important for adequate monitoring of growth and nutritional status in infants.180 Isotope dilution techniques (ID18-o) are widely used to estimate total body water (TBW) and calculate fat-free mass (FFM). A problem of isotope dilution is an underestimation of TBW by the extrapolation tot= 0 approach and an overestimation of TBW by the plateau approach. Using total body electrical conductivity (TOBEC) as the reference technique we validated the extrapolation approach by 149 measurements (boys,n= 76; girls,n= 73) in 50 healthy infants aged 1–12 mo. TOBEC-derived FFM and fat mass were in excellent agreement with Fomon's reference data. Strictly linear relationships with slopes not significantly different from one were found between FFM estimated by TOBEC (FFMTOBEC) and FFM estimated by ID18-O(FFM18-O) (r = 0.98 and residual SD = 0.29 for boys,r= 0.98 and residual SD = 0.32 for girls). FFM18-Owas slightly but significantly lower than FFMTOBEC, the difference being on average 0.18 (±0.24) kg for girls and 0.08 (± 0.21) kg for boys (i.e.respectively 4 (±4.5)% (p< 0.0001) and 1.5 (±3.9)% (p= 0.004) of FFMTOBEC). We conclude that ID18-Ousing the extrapolation tot= 0 approach is suitable for TBW and FFM estimations in groups of infants. Due to the considerable measurement error of ID18-O(estimated at ∼6%), individual TBW18-Oand FFM18-Oestimates should be considered with some caution.

ISSN:0031-3998    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

We have investigated the effect of growth hormone (GH) treatment on GH receptor mRNA expression in five prepubertal children with Prader-Willi syndrome and in eight patients with GH deficiency. An adipose tissue needle biopsy was taken before and after 2–4 mo of GH treatment, and RNA was isolated from adipose tissue and from adipocytes. GH receptor mRNA levels were determined by an RNase protection/solution hybridization assay. To further assess the specificity of the assay for GH receptor mRNAs, RNA extracted from human adipose tissue was subjected to Northern blot analysis. GH treatment significantly increased GH receptor mRNA levels in adipose tissue and isolated adipocytes. Our results indicate that GH may have an important role in regulating the GH receptor in humans.

ISSN:0031-3998    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1995

数据来源: OVID