The effect of acute pain crisis on exhaled nitric oxide levels in children with sickle cell disease

Exhaled nitric oxide (FE(NO)) has been shown to be decreased in children with sickle cell disease. We sought to evaluate the effect of sickle cell vaso-occlusive crisis (VOC) on FE(NO) levels. We measured FE(NO) levels in 42 children with sickle cell disease, 29 in their baseline health and 13 during an acute VOC. There was no difference in FE(NO) levels between children at baseline (15.12 +/- 9.32 ppb) and those during an acute VOC (15.68 +/- 7.26 ppb; P = 0.794). FE(NO) is not a useful marker of acute VOC in children with sickle cell disease.     

The postnatal changes in red blood cell NO levels

AIM: To determine the levels of RBC HbSNO and HbFe(II)NO using chemiluminescence in very low birth weight infants breathing room air, during the first 2 days of life. METHOD: RBC NO values were compared to the levels obtained in cord blood at birth from infants of similar gestational age. Five infants ranging from 25 to 27 weeks of gestation were sampled between 12 and 24 h after birth. These infants were considered as the postnatal group and had normal blood gases at room air. RESULTS: The HbSNO levels were increased in the postnatal group from 49.0 +/- 17.4 nm to 152.3 +/- 54.3 nm (p = 0.0006). There was no difference in HbFe(II)NO levels between the two groups (mean of 267.6 +/- 186.5 nm in cord blood and 180.3 +/- 89.2 nm in the postnatal sample. CONCLUSION: The increase in HbSNO postnatally could be an important mechanism for the neonatal pulmonary adaptation to extra-uterine life.     

Electrophoretic mobility of the fetal red blood cell.

The electrophoretic mobilities of fetal and adult red blood cells have been examined. The mean mobility values for intact fetal and adult erythrocytes were the same, and there was no difference in mobility between the fetal and adult red blood cells treated with neuraminidase. However, a significant difference was observed after trypsin digestion. This may be due to a difference in composition between the fetal and adult red cell membranes.     

Relative rates of fetal hemoglobin and adult hemoglobin synthesis in cord blood of infants of insulin-dependent diabetic mothers

Erythrocytosis, extramedullary erythropoiesis, and increased levels of plasma erythropoietin have been observed in newborn infants of diabetic mothers. Because there is evidence that there is a relationship between increased fetal hemoglobin production and acute erythropoietic expansion, it was considered important to study the proportion of fetal hemoglobin and adult hemoglobin synthesis in newborn infants of insulin-dependent diabetic mothers. Samples from nine newborn infants of diabetic mothers as well as nine control infants, ranging from 36 to 38 weeks of gestation, were incubated in an amino acid mixture containing [14C]leucine. The adult hemoglobin and fetal hemoglobin were then separated by column chromatography on DEAE [O-(diethylaminoethyl)] Sephadex. To confirm that the fetal hemoglobin obtained after Sephadex chromatography was not contaminated with other hemoglobins, several of the DEAE separations from each group were reconstituted and subjected to polypeptide chain elution using carboxyl-methyl cellulose chromatography. The data demonstrated that the newborn infants of diabetic mothers are synthesizing significantly more fetal hemoglobin than is expected for their period of development (82.2 +/- 3.6 v 72.8 +/- 4.2; P less than .005). It is suggested that the in utero environment of the fetus of the diabetic mother causes an increase in fetal hemoglobin synthesis.     

Effects of testosterone and estradiol on ratios of adult to fetal hemoglobin in cell cultures of human fetal liver

The effects of testosterone and 17beta-estradiol on the synthesis of fetal and adult hemoglobins have been studied using a short-term primary cell culture system of human fetal liver at midgestation. There was a significant 23% increase in incorporation of 59Fe into adult hemoglobin relative to the total after the addition of 5 X 10(-8)M testosterone. 17beta-Estradiol (10(-6)M) lowered the incorporation of 59Fe by 21%. beta-Globin chain synthesis, measured as 3H- or 14C-leucine incorporation into globin chains, was identical in control and testosterone-treated cells and only slightly lower when 17beta-estradiol was added. For this reason the observed changes in adult hemoglobin resulting from the action of testosterone and 17beta-estradiol are caused by an indirect effect either in the final hemoglobin assembly or by small changes in the gamma/alpha-chain ratio which may be undetected by the methodology used.     

光疗对早产儿血内皮素及一氧化氮水平的影响及临床意义

目的观察光疗对早产儿血内皮素(ET)和一氧化氮(NO)水平的影响。方法以64例符合光疗条件的高未结合胆红素血症早产儿为研究对象,其中胎龄>32周组31例,胎龄≤32周组33例,并以26例符合光疗条件的高未结合胆红素血症足月儿为对照组,给予24 h连续光疗。用放射免疫法测定ET,用硝酸还原酶法测定NO。在光疗期间定期监测心率、呼吸(包括呼吸暂停)、平均动脉压。结果胎龄≤32周组:光疗24 h与光疗前比较血浆ET值明显升高(P<0.05);光疗12和24 h较光疗前血清NO值升高具有统计学意义(P<0.05);光疗24 h与光疗前血NO/ET比值的升高也具有统计学意义(P<0.05)。胎龄>32周组:仅光疗24 h较光疗前血清NO值升高有统计学意义(P<0.05)。胎龄≤32周组光疗24 h较光疗前心率增快、平均动脉压下降均有统计学意义(P<0.05),光疗24 h血NO/ET比值与平均动脉压呈负相关性。胎龄≤32周组较胎龄>32周组和足月组光疗中呼吸暂停发生例次数明显增多。结论光疗对早产儿尤其小胎龄早产儿血ET、NO影响明显,可能会导致血流动力学改变,应予关注。     

胎鼠急性缺血/再灌注损伤肾NO及NOS的改变

研究宫内急性缺血缺氧及再灌注时胎鼠肾NO水平及NOS活性变化,以无创动脉夹钳夹孕鼠供应子宫和卵巢的动静脉血管,制成宫内急性缺血缺氧及再灌注模型.以硝酸还原酶法和免疫组化法测定胎鼠肾NO水平和NOS活性变化.结果显示随缺血缺氧时间延长NO水平明显降低,与假手术组相比,差异显著P＜0.01.随再灌注时间延长NO水平呈双向改变,尤为缺血缺氧30分钟组.正常时eNOS和iNOS即位于近曲小管.随缺血缺氧及再灌注时间的延长,eNOS光强度逐渐升高,iN-OS光强度逐渐显著减弱,尤为缺血缺氧30分钟再灌注组.表明NO的动态变化可能参与缺血缺氧再灌注损伤过程.缺血缺氧及再灌注后肾NO水平的双相改变可能是eNOS和iNOS活性变化的综合结果.     

Exploring the relationship of peripheral total bilirubin,red blood cell,and hemoglobin with blood pressure during childhood and adolescence

Objective

Total bilirubin is beneficial for protecting cardiovascular diseases in adults. The authors aimed to investigate the association of total bilirubin, red blood cell, and hemoglobin levels with the prevalence of high blood pressure in children and adolescents.

The effects of anticancer drugs on levels of nitric oxide and adrenomedullin

Nephrotoxicity is one of the most important complications of anticancer treatment. Ifosfamide, platinum and methotrexate (MTX) affect renal tubular epithelial cells. Nitric oxide (NO) serves many functions within the kidney. Adrenomedullin (AM) is a potent vasodilator peptide, and may function as a circulating hormone and an autocrine/paracrine mediator involved in the regulation of the cardiovascular system, blood pressure, and renal function. It also has a renoprotective effect and inhibits the generation of reactive oxygen metabolites. To our knowledge, no studies have investigated the effects of anticancer drugs on levels of AM and NO. We investigated the effects of these drugs on the levels of AM and total nitrite, a stable product of NO, and their relations to renal functions. The study was performed in 18 patients (13 males, 5 females) who received chemotherapeutic regimens including high-dose MTX or ifosfamide and platinum. Total nitrite was quantitated by means of the Griess reaction, while AM level was measured by high performance liquid chromatography (HPLC). Plasma total nitrite level (micromol/L) was decreased after chemotherapy (78.73 +/- 47.28 vs. 46.69 +/- 13.89, p: 0.002). A statistically significant difference was found between fractional excretion (FE) of total nitric oxide (FE(NO)) before and after chemotherapy (25.89 +/- 23.11 vs. 51.74 +/- 40.01, p: 0.008). The differences in plasma AM levels (pmol/ml) before (25.07 +/- 4.98) and after (30.20 +/- 1.39) chemotherapy were also statistically significant (p: 0.005). FE(AM) after chemotherapy (1.41 +/- 1.01) was found to be higher than before chemotherapy (0.64 +/- 0.43) (p: 0.000). Our results indicate that some chemotherapeutic agents (high-dose MTX, ifosfamide, and cisplatinium) may cause renal tubular damage. FE(AM) and FE(NO) may also be used for the detection of subclinical acute tubular nephrotoxicity. However, further detailed researches will be necessary to establish the certain role of NO and AM in toxicities of chemotherapeutic agents.