Comparison of T4, T3, rT3 and TSH concentrations in cord blood and serum of infants up to 3 months of age

T4, T3, TSH and rT3 concentrations were measured by radioimmunoassay in cord and postnatal (8--94 days of age) serum samples from randomly selected normal newborn infants (Group I). T4 and TSH levels also were determined in cord and postnatal sera from an additional group of apparently healthy infants 8--260 days of age, whose cord serum T4 levels were in the upper or lower 10% of the normal range of values (Group II). Postnatal T4, T3 and TSH concentrations were stable over this age range; there were no significant differences between male and female infant samples. However, there was a significant decrease in serum rT3 concentrations from 8 to 50 days of age. For the Group I infants, there were significant positive correlations between cord serum T4 and postnatal serum T4 levels, cord serum TSH and postnatal serum TSH levels, and cord serum rT3 and postnatal serum rT3 concentrations. For Group II infants, a significant positive correlation was found for cord T4--postnatal T4 serum concentrations.     

Unusual Lack of the Epitope Recognized by OKT4 on the Helper/Inducer T Lymphocytes

Lack of the epitope recognized by OKT4 monoclonal antibody on the helper/inducer T lymphocytes in a 14-year-old boy with IgA nephritis is described. The lymphocytes reacted normally with OKT3 /Leu4 and OKT8/αLeu2a monoclonal antibodies but not with OKT4 monoclonal antibody. Studies with other monoclonal antibodies (αLeu3a, OKT4A, OKT4B, OKT4C, OKT4D) which also identify the helper/inducer T lymphocyte subset revealed that cells of this population were present in normal numbers among the lymphocytes of the peripheral blood. Staining with OKT4 plus αLeu3a in normal persons indicated that T4 antigen is present on a small population of lymphocytes which lack Leu3a antigen. Further, the intensity of staining of the majority of cells in the subpopulation is increased when these two fluorescienated antibodies are used together. In this patient neither this small OKT4⁺ Leu 3a^- population nor the cells bearing the Leu3a antigen showed OKT4 staining. The findings in the surface marker analysis of E+ OKT8- peripheral lymphocytes which were achieved by panning of the patient's peripheral cells indicated the existence of a population of E⁺OKT8^- peripheral lymphocytes which were achieved by panning of the patient's periphera cells indicated the existence of a population of E⁺ (4A⁺4B⁺4C4D⁺)αLeu3al⁺ ly mphocytes in this patient. Lymphocyte responses to PHA, ConA and PWM, however, were all within normal range. Further, this patient had normal serum immunoglobulin levels and exhibited no symptoms or signs of immunodeficiency. These findings indicate that the patient under study has functionally normal helper/inducer T lymphocytes which lack the epitope recognized by OKT4 monoclonal antibody.     

Establishing a reference range for triiodothyronine levels in preterm infants

Objectives

Thyroid dysfunction affects clinical complications in preterm infants and older children. However, thyroid hormone replacement in preterm infants has no proven benefits, possibly owing to the lack of an appropriate reference range for thyroid hormone levels. We aimed to establish a reference range for triiodothyronine (T3) levels at 1-month postnatal age (PNA) in preterm infants.

Methods

This retrospective study included preterm infants born at a tertiary referral neonatal center at gestational age (GA) < 35 weeks with no apparent thyroid dysfunction, for 6 consecutive years, with follow-up from PNA 2 weeks to 16 weeks. Using thyroid function tests (TFT), the relationships between T3 levels and thyrotropin (TSH) and free thyroxine (fT4) levels, birth weight, GA, postmenstrual age (PMA), and PNA were examined. The conversion trend for fT4 to T3 was analyzed using the T3/fT4 ratio.

Results

Overall, 464 TFTs from 266 infants were analyzed, after excluding 65 infants with thyroid dysfunction. T3 levels increased with fT4 levels, birth weight, GA, PMA, and PNA but not with TSH levels. The T3/fT4 ratio also increased with GA, PNA, and PMA. The average T3 level at 1 month PNA was 72.56 ± 27.83 ng/dL, with significant stratifications by GA.

Conclusions

Relatively low T3 and fT4 levels in preterm infants were considered normal, with T3 levels and conversion trends increasing with GA, PMA, and PNA. Further studies are required to confirm the role of the present reference range in thyroid hormone replacement therapy.     

NYGGF4基因过表达对成熟脂肪细胞线粒体形态及动力学的影响

目的 探讨NYGGF4基因过表达对成熟3T3-L1脂肪细胞线粒体形态及动力学的影响.方法 以3T3-L1前体脂肪细胞为载体,建立NYGGF4基因稳定过表达细胞株,以空载质粒转染的细胞为对照,将前体脂肪细胞诱导分化为成熟脂肪细胞.采用透射电镜观察成熟脂肪细胞的线粒体形态,采用荧光定量PCR技术检测成熟脂肪细胞中线粒体融合基因(Mfn)1 mRNA、Mfn2 mRNA、线粒体动态相关基因(Drp)1 mRNA的表达水平.采用Western blot方法检测Mfn1蛋白、Mfn2蛋白、Drp1蛋白的表达水平.结果 1.电镜观察发现NYGGF4基因过表达的成熟脂肪细胞线粒体体积变小、数量明显减少,线粒体嵴断裂、减少、消失,部分线粒体肿胀,甚至呈空泡状;对照组成熟脂肪细胞的线粒体形态基本正常,线粒体嵴清晰可见,线粒体无明显肿胀、皱缩.2.NYGGF4基因过表达成熟脂肪细胞Mfn1 mRNA及Mfn1蛋白表达水平均显著高于对照组.3.NYGGF4基因过表达成熟脂肪细胞的Mfn2 mRNA、Drp1 mRNA及相应蛋白表达水平与对照组比较差异均无统计学意义.结论 在3T3-L1成熟脂肪细胞中,NYGGF4基因过表达可导致线粒体形态发生变化、数量减少,同时上调Mfn1 mRNA和Mfn1蛋白表达水平,提示NYGGF4基因在成熟脂肪细胞中过表达能影响细胞线粒体形态及动力学.     

Hypothyroidism in a breast-fed preterm infant resulting from maternal topical iodine exposure

Hypothyroidism developed in a preterm infant, whose initial screening thyroid function test results were normal, at 2 weeks of life. The infant's mother was packing her Caesarian incision with iodine soaked gauze, resulting in a markedly increased breast milk iodine concentration. Treatment with oral L-thyroxine normalized thyroid function tests.     

解偶联蛋白4基因在3T3-L1脂肪细胞诱导分化中的表达水平

目的　观察 3T3 L1脂肪前体细胞诱导分化过程中解偶联蛋白 4 (UCP4 )基因表达水平变化 ,探讨UCP4基因与肥胖发生之间的关系。方法　体外培养 3T3 L1细胞 ,诱导细胞分化 ,采用RT PCR技术在细胞分化成熟的不同时段检测脂肪细胞中UCP4基因mRNA表达水平。结果　UCP4基因高表达于 3T3 L1脂肪前体细胞中 ,随细胞分化成熟该基因表达水平渐下调。UCP4基因表达水平在诱导分化前 (d - 1)至d0、d0～ 3、d4～6、d7～ 8、d9～ 10内无显著性差异 (P >0 .0 5 ) ,余各时段表达水平均有显著差异 (P均 <0 .0 1)。结论　UCP4基因与肥胖发生相关 ,其在 3T3 L1细胞分化过程中表达逐渐下调可能有利于脂肪细胞的脂质积聚     

Association of antenatal steroid use with cord blood immune biomarkers in preterm births

Objectives

To evaluate the effect of maternal administration of antenatal steroids (ANS) on cord blood cytokine levels at birth in preterm infants.

Methods

Cord blood cytokine concentrations were measured for pro-inflammatory cytokines (IL-1β, IL-6, and IL-8); anti-inflammatory cytokines (IL-4, IL-10 and TGF-β); and neurotrophic cytokines (BDNF, NT-3, and NT-4) in two hundred preterm infants. Data were analyzed using multivariable linear regression to model the independent and joint effects of ANS and inflammation on mean log cord blood cytokine concentrations adjusted for gestational age and Apgar scores.

Results

Exposure to ANS had no significant effect on the cord blood concentrations of cytokines measured in this study. All three pro-inflammatory cytokine levels and levels of IL-10 were significantly increased and cord blood levels of TGF-β and NT-3 were significantly decreased in infants with placental inflammation.

Conclusion

Although exposure to ANS did not have any significant effect on cord blood levels of cytokines, there was a trend toward the attenuation of inflammatory response and higher levels of neurotrophic cytokines in infants born to mothers with placental inflammation and exposure to ANS compared to infants born to mothers with placental inflammation and no ANS exposure.     

Intrauterine growth restriction and circulating neurotrophin levels at term

BACKGROUND: Intrauterine growth restricted (IUGR) fetuses are those with estimated weight <10th customized centile, displaying signs of chronic malnutrition and hypoxia leading to brain sparing effect. Neurotrophins, [Nerve Growth Factor (NGF), Brain Derived Neurotrophic Factor (BDNF), Neurotrophin-3 (NT-3), Neurotrophin-4 (NT-4)] are important for pre- and post-natal brain development. AIMS: To investigate circulating NGF, BDNF, NT-3 and NT-4 levels in IUGR and appropriate for gestational age (AGA) fullterm fetuses and neonates (day-1 [N1] and day-4 [N4]) and in their mothers. STUDY DESIGN: Prospective case control study. SUBJECTS: 60 mothers and their single 30 IUGR and 30 AGA fullterm fetuses and neonates. OUTCOME MEASURES: Determination, by enzyme immunoassays, of NGF, BDNF, NT-3 and NT-4 plasma levels. RESULTS: No statistically significant differences existed between IUGR and AGA maternal, fetal and neonatal levels of BDNF, NT-3 and NT-4. NGF was significantly higher in AGA than IUGR maternal (p=0.007), fetal (p=0.01), neonatal day 1 (p=0.043) and 4 (p=0.003) plasma, and positively correlated with the infants' centiles and birthweights. IUGR and AGA maternal neurotrophins were higher than the respective fetal and neonatal ones and no correlation with gender or delivery mode in both groups was observed. CONCLUSIONS: In the perinatal period, circulating levels of BDNF, NT-3 and NT-4 do not differ in IUGR and AGA pregnancies, in contrast to NGF levels, which are higher in the AGA group. NGF is the only neurotrophin correlating with customized centiles and birthweights of the infants. Neurotrophin concentrations are higher in maternal plasma and do not depend on gender.     

三甲基化组蛋白H3赖氨酸4对调节性T淋巴细胞foxp3基因表达的影响

目的探讨天然调节性T淋巴细胞(nTreg)的三甲基化组蛋白H3赖氨酸4(H3K4me3)对foxp3基因的影响,寻找维持调节性T淋巴细胞(Treg)表型长期稳定的方法。方法使用免疫磁珠细胞(MACS)分选法从健康人外周血中分离出CD4+CD25+Treg。对CD4+CD25+Treg分别进行0 d、3 d、7 d培养,其中0 d为阴性对照组,3 d为阳性组1,7 d为阳性组2,采用流式细胞仪(FCM)对0 d、3 d、7 d nTreg膜表面标志CD25的变化进行检测,并分别对培养0 d、3 d、7 d的nTreg细胞通过染色质免疫共沉淀(ChIP-PCR)法检测foxp3基因启动子区H3K4me3及DNA水平变化。结果 1.使用细胞计数Kit-8(CCK-8)法确定植物血凝素(PHA)质量浓度在10 mg.L-1时为最佳的药物质量浓度,对Treg细胞的增殖作用最为显著。nTreg细胞培养0 d、3 d、7 d的表型变化呈递减趋势。随着培养时间(0 d、3 d、7 d)的延长,与foxp3基因启动子区结合的H3K4me3表达逐渐减少。2.采用ChIP-PCR法对培养0 d、3 d、7 d的nTreg细胞检测与H3K4me3结合的foxp3基因启动子区DNA水平变化。DNA凝胶电泳图显示,0 d、3 d在204 bp处可见条带(灰度值分别为2.31、0.91),7 d有模糊条带或无条带。三者比较差异有统计学意义(P<0.05)。结论 PHA不能维持Treg细胞的表型稳定,其机制与H3K4me3减少有关。     

T Cell Activation and T Cell Receptor Variable Region Gene Usage in Measles

T cell activation and T cell receptor variable (V) regions were studied with monoclonal antibodies in peripheral blood lymphocytes from 22 patients with measles. Increased (> 5%) activated T cells (HLA-DR⁺ CD3⁺ cells) were noted in 14 of the 22 patients. Elevations of Vβ5⁺ and Vβ8 + T cells were observed in two and four patients, respectively, and appeared to be associated with T cell activation. The duration of fever was significantly prolonged in those with increased (> 10%) activated T cells (p < 0.01). These results suggest that T cell activation and the preferential expansion of Vβ8⁺ and Vβ5⁺ T cells are associated with the pathogenic process of measles.     

Follow-up of newborns with elevated screening T4 concentrations

OBJECTIVE: To determine the type and incidence of hyperthyroxinemic disorders detected by follow-up of infants with elevated screening total T4 (TT4) values. STUDY DESIGN: Infants born in Oregon with a screening TT4 measurement >3 SD above the mean were offered enrollment. Serum TT4, free T4, total T3, free T3, and thyroid-stimulating hormone concentrations were measured in study infants and their mothers. RESULTS: Over a 20-month period, 101 infants (51 boys) and their mothers enrolled in the study (of 241 eligible infants), from a total screening population of 80,884; 17 infants were identified with persistent hyperthyroxinemia (TT4 >16 microg/dL). Ten had thyroxine-binding globulin excess (1:8088), 5 had evidence for increased T4 binding but not thyroxine-binding globulin excess (1:16,177), and 2 had findings compatible with thyroid hormone resistance (1:40,442); the other 84 infants had transient hyperthyroxinemia. Sequence analysis revealed a point mutation in the thyroid hormone receptor-beta gene in one infant with thyroid hormone resistance; no mutation was identified in the other infant. CONCLUSIONS: Although neonatal Graves' disease occurs in approximately 1 in 25,000 newborn infants, we did not detect any case among 80,884 infants, most likely because their mothers were receiving antithyroid drugs. Although the other hyperthyroxinemic disorders in the aggregate occur frequently (1:4758) and may benefit from detection, in general they do not require treatment.     

Peripheral expansion of Vδ1-Jδ1/Jδ2+γδT cells and large granular lymphocytes in a patient with Wiskott-Aldrich syndrome

A 7 month old Japanese boy was diagnosed to have Wiskott-Aldrich syndrome (WAS) because of eczema, thrombocytopenia, progressive immune defect and CD43 (sialophorin) abnormality. He had developed repeated infections since 16 months of age. γδT cell-receptor positive T cells in the peripheral blood were gradually increased from 3.1% (7 months of age) to 5.6% (12 months), 19.6% (18 months) and 56.7% (25 months). The phenotypes of expanded γδT cells were δTCS1-positive (Vδ1-Jδ1/Jδ2) and CD8 dim-positive. The proportion of increased granular lymphocytes correlated well with that of γδT cells. The significance of peripheral expansion of γδT cells and granular lymphocytes in WAS is discussed.     

Markers of operational immune tolerance after pediatric liver transplantation in patients under immunosuppression

A prospective identification of the estimated 20–50% of pediatric LTX recipients developing operational tolerance would be of great clinical advantage. So far markers of immune tolerance – T‐cell subpopulations or gene expression profiles – have been investigated only retrospectively in successfully weaned patients. Fifty children aged 8–265 months (median 89) were investigated 1–180 months (median 44) after LTX under ongoing immunosuppression. T‐cell subpopulations were measured during regular post‐transplant visits using FACS (Vδ1‐ vs. Vδ2‐γδ‐T cells and Tregs). A Vδ1/Vδ2‐γδ‐T‐cell ratio ≥1.42 previously reported in operational tolerance was found in 12 of 50 (24%) patients. In analogy, a Treg count ≥44 per μL was found in 35 of 50 (70%) patients and a Treg proportion ≥2.23% of CD3⁺‐T cells in 39 of 50 (78%) patients. Only 9 of 50 patients (18%) fulfilled both criteria. The parameters Vδ1/Vδ2‐γδ‐T‐cell ratio and Tregs were not significantly correlated to each other or with donor type or immunosuppression. Vδ1/Vδ2‐γδ‐T‐cell ratio was more stable in serial examinations compared with Treg analyses. The observed proportion of 18% pediatric LTX patients with potential operational tolerance is in accordance with previous reports. However, clinical experience shows that rejections may happen even after long‐time weaning of immunosuppression. This suggests that operational tolerance is a dynamic process, with uncertain prediction by Vδ1/Vδ2‐γδ‐T‐cell ratio and/or Tregs under immunosuppression.