摘要:

To determine whether human milk contained soluble receptors and cytokine antagonists that might contribute to its anti-inflammatory properties, ELISA and enzyme-amplified sensitivity immunoassay methods were used to quantitate soluble intercellular and vascular cell adhesion molecules, soluble E-selectin, soluble IL-6 receptor, IL-1 receptor antagonist, and soluble tumor necrosis factor-α (TNF-α) receptors I and II in human milk and colostrum. Soluble adhesion receptors (soluble intercellular and vascular cell adhesion molecules and soluble E-selectin) were present in colostrum at levels approximately equal to serum, whereas milk levels were significantly lower. Both colostrum and milk contained soluble IL-6 receptor, but the levels present were significantly lower than that reported for serum. The colostrum contents of IL-1 receptor antagonist (672 ± 202 pg/mL), TNF-α receptor I (>3703 ± 305 pg/mL), and TNF-α receptor II(>4507 ± 770 pg/mL) were significantly elevated over serum/plasma levels. Milk levels of IL-1 receptor antagonist and TNF-α receptor I were also greater than serum/plasma levels, but lower than colostrum levels. Examination of sequential milk specimens collected from seven women over a period of 2-6 mo showed that IL-1 receptor antagonist and TNF-α receptors I and II persisted throughout lactation. Column chromatographic fractionation of colostrum and milk demonstrated that soluble TNF-α receptors I and II had molecular sizes up to 60 kD, suggesting that they might be associated with other molecules. Antigen assays for TNF-α in colostrum and milk, as well as chromatographic fractionation experiments, showed that, although present, most TNF-α was not “free” in colostrum or milk, consistent with the observed content of soluble TNF-α receptors I and II. These studies demonstrate that human milk and colostrum contain soluble receptors and cytokine antagonists, materials which could contribute to their anti-inflammatory properties.Abbreviations: sICAM-1,soluble intercellular adhesion molecule-1;sVCAM-1,soluble vascular cell adhesion molecule-1;sE-selectin,soluble E-selectin;sIL-6R,soluble IL-6 receptor;TNF,tumor necrosis factor;sTNF RI,soluble tumor necrosis factor-α receptor I;sTNF RII,soluble tumor necrosis factor-α receptor II;IL-1RA,IL-1 receptor antagonist;EASIA,enzyme-amplified sensitivity immunoassay;HRP,horseradish peroxidase

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Ribonucleotides in human milk have been claimed to have several effects in recipient infants. It is, however, not known whether the nucleotides found in human milk result from degradation of nucleic acids or are actively secreted as a response to a nutritional demand of the infant. Furthermore, little is known of the newborn infant's endogenous capacity to digest nucleic acids to absorbable products. We therefore analyzed human milk, during established lactation, with respect to the concentration of nucleic acid and ribonucleotide metabolites. Expressed as nucleotide equivalents, 68 ± 55 μmol/L were present as nucleic acid, 84 ± 25 μmol/L as nucleotides, and 10 ± 2 μmol/L as nucleosides. The nucleotide/nucleoside profile showed a substantial predominance for pyrimidines and uric acid. This specific profile could, at least to some extent, result from limited catalysis during storage of the milk in the breast, because enzymes capable of degrading nucleotides were found in the milk. To evaluate the endogenous capability of newborn infants to metabolize RNA and nucleotides, fetal small intestine was analyzed for relevant digestive enzymes. Such intestine, from a fetus of 22-wk gestation, digested RNA to cytidine, uridine, and uric acidin vitro. Furthermore, a fetal small intestinal homogenate generated a net increase in pyrimidines and purines when incubated with human milk, whereas when incubated with infant formula, devoid of nucleic acids, it did not.

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

To identify the developmental changes in monthly urinary gonadotropin and ovarian hormone excretion, consecutive 30-d first morning void urinary specimens were collected from 36 normal girls, one normal woman, and 15 female patients with idiopathic precocious puberty. Of these children, three normal girls and three patients with precocious puberty volunteered to collect these specimens on 2-3 occasions over a time interval of 0.5-3.2 y. When sampled, six were early prepubertal, nine late prepubertal, eight early pubertal, eight mid-pubertal, and eight late pubertal normal girls, and six were early pubertal and 14 mid-pubertal patients with precocious puberty. The mean level of monthly urinary LH, FSH, and total estrogen excretions increased with pubertal maturation. In prepuberty, the mean LH level was lower than the mean FSH level, and neither showed significant episodic fluctuations. In early puberty, mean FSH levels increased with remarkable fluctuations, and mean LH levels were low with few variations in the course of a month. At the onset of puberty, gonadotropin excretory patterns underwent specific changes, showing at the same time periodically and every other day fluctuating patterns. Urinary total estrogen and pregnanediol excretion fluctuated independently from these periodic variations in urinary gonadotropins. These patterns were observed in six out of 16 patterns in normal pubertal girls and 10 out of 20 patterns in precocious puberty. Once the urine LH level exceeded the urine FSH level, however, these periodic variations disappeared. The cycle of a normal postmenarcheal girl aged 14 y showed a pattern similar to that of a normal adult. In patients with precocious puberty, the hormonal patterns were similar to those of sexual stage-matched normal girls.Abbreviations: FMV,first morning voided;G,group;LHRH,LH-releasing hormone

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

We have experimentally restricted placental growth in the sheep to investigate the impact of reduced substrate delivery on fetal pituitary proopiomelanocortin (POMC) mRNA levels and on circulating ACTH 1-39, immunoreactive ACTH, and cortisol concentrations during late gestation. Endometrial caruncles were removed in nine ewes before mating to reduce the number of placentomes formed [placental restriction group (PR)]. Fetal arterial Po2and O2saturation were reduced in the PR group (2.0± 0.1 kPa and 42.8 ± 1.1%,n= 9) when compared with control fetuses (3.1 ± 0.1 kPa and 66.4 ± 0.9%,n= 10). The ratio of anterior pituitary POMC mRNA:18 S ribosomal RNA was also lower (p< 0.05) in the PR group (0.49 ± 0.05) when compared with the control group (0.80 ± 0.12) after 140 d of gestation. In contrast, plasma concentrations of ACTH 1-39 and immunoreactive ACTH were similar in the PR and control groups throughout late gestation. Plasma ACTH 1-39 concentrations increased (p< 0.006) between 128 and 134 d of gestation, in both the PR (122-128 d: 2.70 ± 0.34 pmol/L: 134-141 d; 7.07 ± 1.57 pmol/L) and control (122-128 d; 3.36 ± 0.56 pmol/L: 134-141 d; 10.78 ± 2.88 pmol/L) groups. Combined adrenal weight was higher (p< 0.005) in the PR group (130 ± 10 mg/kg) compared with controls (80 ± 1 mg/kg) at 140 d of gestation, and plasma cortisol concentrations were also higher (p< 0.02) in PR than control fetuses between 127 and 141 d of gestation. These changes imply that the fetal hypothalamopituitary-adrenal axis is operating at a new central set point in the growth-restricted fetus.Abbreviations: ir,immunoreactive;POMC,proopiomelanocortin;PR,placental restriction;rRNA,ribosomal RNA

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Chorioallantoic artery blood flow and heart rate were studied in the chick embryo from stage 34 until stage 43 (d 9-16 of 21-d incubation). Baseline blood flow profiles of the chorioallantoic artery were measured with a flow probe (Transonic) in 100 chick embryos. The eggs were opened at the air cell and placed in a small plexiglass box with a continuous gas flow of a N2/O2mixture (5 L/min), at 38 °C and 60% humidity. The chorioallantoic artery was localized near the fetal abdomen and placed in the lumen of the Transonic flow probe. The heart rate was derived from the blood flow signal. The mean chorioallantoic artery blood flow rose from 0.35± 0.14 mL/min (mean ± SD) at stage 34 to 3.13 ± 1.49 mL/min at stage 43 (R2= 0.69,p< 0.0001), which correlated with an increase in body weight (1.51 ± 0.18 g to 15.08 ± 0.76 g). Heart rate increased from 195 ± 38 beats/min at stage 34 to 289 ± 13 beats/min at stage 43 (R2= 0.38,p< 0.0001). The chorioallantoic artery blood flow, which in avian species correlates with umbilical blood flow in mammals, increased with incubation time as reported in the mammalian fetus. This study shows that the chick embryo could be useful as a preparation for further perinatal cardiovascular research.Abbreviations: CABF,chorioallantoic artery blood flow;CAM,chorioallantoic membrane

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Administration of large doses of recombinant granulocyte colony-stimulating factor (rG-CSF) to mice results in diminished erythropoiesis. Hyporegenerative anemia does not occur in adult humans as a consequence of treatment with rG-CSF, but it is not clear whether this will be a problem in neonates. Because rG-CSF is currently being tested as a treatment for neutropenia in neonates, we assessed the possibility that such treatment will diminish their erythropoiesis. To do this, we added rG-CSF,in vitro,to clonogenic cultures of hematopoietic progenitors obtained from the bone marrow and liver of seven human fetuses and from the umbilical cord blood of five term and five preterm infants. The range of rG-CSF concentrations tested (0.1-10.0 ng/mL) included the peak concentrations measured in the blood of neonates receiving rG-CSF treatment on experimental protocols. Inclusion of rG-CSF in the cultures did not diminish clonal maturation of fetal erythroid (erythroid colony-forming and burst-forming unit) progenitors, nor did it reduce the number of normoblasts generated per erythroid progenitor cell colony. On the basis of these studies we predict that administration of rG-CSF to neonates will not result in down-modulation of erythropoiesis.Abbreviations: BFU-E,burst-forming unit-erythroid;CFU,colony-forming unit;CFU-E,colony-forming unit-erythroid;Epo,erythropoietin;rEpo,recombinant erythropoietin;G-CSF,granulocyte colony-stimulating factor;rG-CSF,recombinant granulocyte colony-stimulating factor;α-MEM,minimal essential medium, α modification

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Preeclampsia, a common complication of pregnancy, contributes significantly to maternal and fetal morbidity and mortality. It may lead to both quantitative and qualitative defects of maternal and neonatal platelets. In this prospective study, flow cytometry has been used to study expression of platelet-surface glycoproteins (GPs) on maternal and neonatal platelets of both healthy and preeclamptic subjects. We studied 15 preeclamptic women, 20-44 y of age, and their newborns (median gestational age, 32 wk; range, 26-38) and seven healthy women (aged 26-41 y) and their healthy newborns(median gestational age, 38 wk; range, 38-42). Compared with their healthy and preeclamptic mothers, resting platelets from neonates expressed significantly less CD41 and CD9. Thrombin activation resulted in significant increases in platelet-surface expression of CD62P, CD63, CD41, CD9, and CD36 in neonates and their healthy mothers. Compared with neonates of healthy mothers, platelets from neonates of preeclamptic mothers expressed lower levels of CD62P, CD63, CD9, and CD36 on activated platelets. These findings suggest that preeclampsia influences the expression of platelet-surface GPs on neonatal and maternal platelets, which may affect platelet function, leading to an additional risk for bleeding in thrombocytopenic neonates of mothers with preeclampsia.Abbreviations: CD,cluster of differentiation;FITC,fluorescein-isothiocyanate;GP,glycoprotein;PE,phycoerythrin;CD9,p24;CD36,GPIV;CD41,GPIIb-IIIa;CD42b,GPIb;CD62P,P-selectin;CD63,lysosome integral membrane protein

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

Oral administration of human serum immunoglobulin reduces the duration of diarrhea and of rotaviral excretion in children. To investigate thein vitroeffects of immunoglobulin on virusenterocyte interaction, Caco-2 cells were infected withRotavirusstrain SA11. Immunoglobulin was added prior to and at various times postinfection. Indirect immunofluorescence was performed with an antibody against VP-6 rotaviral antigen. Cell viability and monolayer transepithelial electrical resistance (TEER) were monitored. Immunofluorescence showed a perinuclear distribution in 90% of cells.Rotavirusinfection induced a progressive decrease in TEER and a parallel reduction in cell viability, depending on viral load. Preincubation of the virus with immunoglobulin prevented cell infection as judged by immunofluorescence. Immunoglobulin addition to infected cells partially prevented the decrease in TEER and induced a later shift of TEER toward increasing values, suggesting restoration of monolayer's integrity. The efficacy of immunoglobulin depended on its concentration and on the time of its addition. These results indicate that immunoglobulin is effective in preventing infection and in reducing cell damage, through a direct anti-Rotavirusaction and may indicate that immunoglobulin should be administered in the early phase of diarrhea, to reduce the severity ofRotavirusinfection.Abbreviations: TEER,transepithelial electrical resistance;p.i.,postinfection;DMEM,Dulbecco's modified Eagle's medium;PFU,plaque-forming unit

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:0031-3998    

出版商:OVID    

年代:1996

数据来源: OVID