铁蛋白受体放射配体结合分析法

本文采用差速离心法制备胎盘微绒毛膜，用＾１２５Ｉ－Ｈｕｎｔｅｒ试剂联接标记铁蛋白，在国内首次建立了胎盘微绒毛膜铁蛋白受体放射配体分析法，并进行了最适反应条件及铁蛋白受体的特性研究。所标记的＾１２５Ｉ－铁蛋白放化纯达９５％以上，且免疫活性和生物活性均较好。用放射配体受体分析测定了１１例正常足月孕妇胎盘微绒毛膜铁蛋白受体数为（３．５３４±１．１０５）×１０＾１２位点／毫克膜蛋白，亲和力常数Ｋａ为（２．     

缺铁孕妇胎盘铁相关蛋白受体同步检测及意义

探讨胎盘微绒毛膜铁相关蛋白受体包括铁蛋白受体（ＦｎＲ）、转铁蛋白受体（ＴｆＲ）在孕母缺铁时表达的变化及其在母婴铁代谢中的作用，对此研究的重点是观察检测胎盘的有关指标。足月健康孕妇胎盘１１例，轻度ＩＤＡ孕妇胎盘１４例。采用差速离心法提取胎盘微绒毛膜蛋白，采用受体放射配体结合分析法检查ＦｎＲ、ＴｆＲ。结果数据：１１例健康孕妇胎盘ＴｆＲ位点数为（４．０５７±１．３２）×１０ｓｉｔｅｓ／ｍｇ·ｐｒｏ，Ｋａ值为（１．６２２±０．５８４）×１０ｍｏｌ－１。Ｌ；ＦｎＲ位点数为（３．５３４±１．１０５）×１０ｓｉｔｅｓ／ｍｇ·ｐｒｏ，Ｋａ值为（２．２０３±０．６２２）×１０ｍｏｌ－１．Ｌ。１４例轻度ＩＤＡ孕妇胎盘ＴｆＲ位点数为）６．９８４±１．７５４）×１０ｓｉｔｅｓ／ｍｇ·ｐｒｏ，Ｋａ为（１．５４１±０．７９４）×１０ｍｏｌ·Ｌ；ＦｎＲ位点数为（８．９３６±２．４０７）×１０ｓｉｔｅｓ／ｍｇ．ｐｒｏ，Ｋａ值为（１．２４９±０．３６５）×１０ｍｏｌｄ－１ｆ．Ｌ。轻度ＩＤＡ孕妇胎盘ＴｆＲ表达较正常高１．７２倍，ＦｎＲ表达较正常高出２．５３倍。结果表明：轻度ＩＤＡ孕妇胎盘ＴｆＲ、ＦｎＲ同步升高；此时胎盘可通过ＴｆＲ、ＦｎＲ的增?     

中期孕母不同铁营养状态时胎盘微绒毛膜铁蛋白受体表达及其意义

为了了解中孕期胎盘铁蛋白受体（FnR）表达水平及其在母-胎铁代谢中的作用，本文采用FnR放射配体结合分析法，对30例中孕期（16－28周）胎盘微绒毛膜FnR表达进行了研究。结果发现：（1）孕母铁状态正常时，胎盘微绒毛膜FnR位点数为（9．63士4．72）X1012个／mg膜蛋白，与同期测定的足月孕胎盘FnR的表达水平相似（P＞0．1）；（2）隐性缺铁及轻度缺铁性贫血时，FnR位点数明显增高（PO．25）。表明胎盘微绒毛膜FnR在母-胎铁代谢中起重要的转运及调节作用，提示中期孕母严重铁缺乏时可能影响胎盘的铁转运，进而影响胎儿的铁供给。     

新生猪缺氧缺血性脑损伤中谷氨酸受体变化的研究

为探讨新生儿缺氧缺血性脑病的发病机理，选用健康新生猪24只并随机分为正常对照组（A组）、缺氧缺血性脑损伤（HIE）后2小时组（B组）及HIE后24小时组（C组）。采用放射配体结合法检测各级脑组织突触膜上谷氨酸受体（GluR），结果发现HIE后24小时GluR的最大结合住点数（Bmax）：12．4±2.1pmol／mg蛋白，显著低于A组（17.4±3．1pmol／mg蛋白）和B组，但各组间GluR的亲和力（Kd）均无显著性差异。结果提示，GlUR的改变可能参与了新生猪HIE的发病。     

小儿急性白血病骨髓细胞糖皮质激素受体表达及其临床意义

本文应用放射配体结合法测定了３０例ＡＬＬ骨髓细胞ＧＣＲ为７８７３±３００２位点／细胞；１７例ＡＮＬＬ为６１１３±１６２２位点／细胞（Ｐ〈０．０５）。形态学分型Ｌ１型１７例，ＧＣＲ为７２６７±３１７８位点／细胞；Ｌ２型１３例，ＧＣＲ为７６５０±３３６２位点／细胞（Ｐ〉０．０５）。临床分型标危型ＡＬＬ１４例，ＧＣＲ为８９９８±１９６３位点／细胞；高危型９例为５８４７±３８８５位点／细胞（Ｐ〈０．０５）     

人外周血T淋巴细胞集落(TL—CFU)培养的研究

本文报道用PHA作为刺激物，采用简化的一步法在甲基纤维素培养基上培养人外周血T淋巴细胞集落（TL一CFU）获得成功，并对TL一CFU培养的适宜条件进行了探讨；同时，对集落组成细胞进行了T淋巴细胞表型分析；在此适宜条件下，对健康成人外周血TL—CFU产率进行了测定。结果显示：（1）培养体系中PHA2ul／ml、20％小牛血清（FCS）、5×10（－5）M2一巯基乙醇、0．8％甲基纤维素、60％RPMI1640、2×105MNC／ml、培养时间七天为TL—CFU培养的适宜条件；（2）集落组成细胞中CD3+细胞占92．5±4．59％、CD4+、CD8+细胞分别为57．83±7．85％及46．66±4．76％、CD4／CD8之比为1．24±0．17；（3）健康成人外周血TL一CFU产率为351．58±21.97／2×105MN。基于上述结果认为，该培养方法操作简便、集落产率高，为研究T淋巴细胞及其亚群提供了条件。     

新生牛缺氧模型血糖及胰岛素受体的研究

为了观察缺氧对新生动物血糖的影响及血糖变化的可能原因，使１３头新生小牛吸入５．６％低浓度氧２小时，观察缺氧状态下的血糖变化，用受体放射配基结合分析中Ｓｃａｔｃｈａｒｄ系统分析血细胞胰岛素受体。结果：缺氧后酸中毒且血糖升高（从４．２０±０．１８到９．２９±０．３２ｍｍｏｌ／Ｌ），缺氧２小时血细胞胰岛素受体的低亲和性结合位点数从４７４３±７８０下降到２２１３±５１２个／细胞。提示缺氧影响了新生小牛血糖及血细胞胰岛素受体的代谢。     

先天性尿道下裂阴茎皮肤细胞雌雄激素受体表达及胞核内的聚集

目的：探索先天性尿道下裂与阴茎皮肤细胞雄激素受体（ＡＲ）、雌激素受体（ＥＲ）的表达及细胞核内的聚集的关系。方法：通过受体的放射配基结合分析，对２８例不同程度的先天性尿道下裂患儿外生殖器皮肤细胞内的ＡＲ、ＥＲ的表达及细胞内的分布进行了测定。结果：实验显示尿道下裂患儿外生殖器皮肤细胞内及胞核内ＡＲ量较正常对照减少（Ｐ＜０．０１），尿道下裂的严重程度与细胞内及细胞核内的ＡＲ量无关（Ｐ＞０．０５）。细胞内总ＥＲ与正常无显著性差异（Ｐ＞０．０５），胞核内ＥＲ量较正常对照减少（Ｐ＜０．０５）。结论：ＡＲ异常是先天性尿道下裂的原因之一，先天性尿道下裂也属于雄激素不敏感综合征的范畴，而核内ＥＲ的减少可能为继发性改变     

小儿急性白血病骨髓细胞糖皮质激素受体表达及其临床意义

本文应用放射配体结合法测定了３０例ＡＬＬ骨髓细胞ＧＣＲ为７８７３±３００２位点／细胞；１７例ＡＮＬＬ为６１１３±１６２２位点／细胞（Ｐ＜０．０５）。形态学分型Ｌ１型１７例，ＧＣＲ为７２６７±３１７８位点／细胞；Ｌ２型１３例，ＧＣＲ为７６５０±３３６２位点／细胞（Ｐ＞０．０５）。临床分型标危型ＡＬＬ１４例，ＧＣＲ为８９９８±１９６３位点／细胞；高危型９例为５８４７±３８８５位点／细胞（Ｐ＜０．０５）。对１８例ＡＬＬ经联合化疗完全缓解前后比较发现，ＧＣＲ分别为８１１５±３２５８位／细胞和４６６９±２１０６位点／细胞（Ｐ＜０．０１）。本实验同时测定了ＡＬＬ和ＡＮＬＬ患儿血浆皮质醇浓度，平均分别为１１２．２０±４１．１４ｎｇ／ｍｉ和１０４．６５±４３．４９ｎｇ／ｍｌ，相关系数分别为ｒ＝０．１５和０．１１，说明ＧＣＲ表达水平不受皮质醇含量的影响。     

脐动、静脉造血干细胞/祖细胞的比较

目的探讨胎盘绒毛膜在胎儿期造血中的作用,寻找造血干/祖细胞的新来源,供临床移植应用。方法分别测定并比较脐动、静脉血中CD+34细胞含量及粒-单细胞集落形成单位（CFU-GM）、混合集落形成单位（CFU-MIX）、高增殖潜能集落形成单位（HPP-CFU）集落的产率。结果脐静脉中CD+34及CD+34/CD-38细胞含量分别为（1.25±0.94）％和（0.61±0.50）％,较脐动脉血中的含量（0.77±0.50）％、（0.33±0.27）％显著增高（P均<0.05）;脐动、静脉血单个核细胞（MNC）大多处于静止期（>95%）,二者差异无显著性（P＞0.05）,但合成期细胞的比率在脐静脉血中为（2.2±1.8）％,明显高于脐动脉血的比率（0.9±1.0）％;脐静脉血中CFU-GM、CFU-MIX和HPP-CFU的产率分别为（49.7±28）/2×105MNC、（8.7±4.6）/1×105MNC和（1.6±1.2）/1×105MNC,明显高于脐动脉血的产率（18±9）/2×105MNC、（5.2±2.7）/1×105MNC和（0.4±0.4）/1×105MNC,差异有显著性（P均<0.05）。结论脐静脉血中造血干/祖细胞的含量高于脐动脉,提示胎盘绒毛膜在胎儿期造血中具有一定的作用,并有可能成为造血干/祖细胞的又一来源。     

中期孕母与胎儿间铁营养状态的关系

为进一步确定中期孕母铁缺乏症对胎儿铁代谢的影响，我们研究了中期孕母与胎儿铁代谢的关系。结果发现，二者的红细胞碱性铁蛋白（ＥＦ）值是显著正相关关系（ｒ＝０．４０２１，Ｐ＜０．０２５），且孕母中度ＩＤＡ组胎儿ＥＦ值下降了１３．６％，而母、胎其它铁代谢指标间无相关关系；说明孕母铁缺乏影响其胎儿的铁储备，尤以严重铁缺乏时明显，证实孕母铁缺乏可致胎儿出生后易患铁缺乏症。     

Activity and expression of the Na(+)/H(+) exchanger in the microvillous plasma membrane of the syncytiotrophoblast in relation to gestation and small for gestational age birth

The effect of gestational age, low birth weight, and umbilical plasma pH on the activity and expression of the Na(+)/H(+) exchanger in the microvillous plasma membrane (MVM) of the placental syncytiotrophoblast was investigated. MVM were isolated from placentas of fetuses delivered in the first and second trimesters and from appropriately grown for gestational age (AGA) and small for gestational age (SGA) babies born at term. Na(+)/H(+) exchange activity (amiloride-sensitive Na(+) uptake) was higher (p<0.05) in second trimester and term AGA MVM versus first trimester MVM (median [range]: 1.80 [1.01-3.03], 1.72 [1.16-3.15] versus 1.48 [0.92-1.66] nmol/mg protein/30s, respectively, n = 6, 12, and 9). As regards exchanger isoforms, Western blotting showed that NHE1 expression did not change across gestation, but NHE2 and NHE3 expression were lower (p<0.01) in the first and second trimesters than in term AGA MVM. There were no differences in Na(+)/H(+) exchanger activity or in NHE1-3 expression in term AGA MVM versus SGA (n = 11) MVM. There was no correlation between exchanger activity and umbilical artery or vein plasma pH, although with a relatively small number of samples (n = 12 and 15, respectively). We conclude that there is differential regulation of the activity and expression of Na(+)/H(+) exchanger isoforms in the MVM over the course of gestation in normal pregnancy; this is not affected in pregnancies resulting in SGA babies at term.     

Serum transferrin receptor in children and adolescents with inflammatory bowel disease

Iron studies are difficult to interpret in patients with chronic inflammatory states such as inflammatory bowel disease (IBD). Serum transferrin receptor (TfR) has been reported to be a reliable tool for the diagnosis of iron deficiency in adults. Our aim was to evaluate the role of serum TfR in diagnosing iron deficiency in children and adolescents with IBD. A total of 63 consecutive patients with IBD, aged 9 to 22 years (median 15 years), were tested for serum haemoglobin level, mean corpuscular volume (MCV), and serum iron, transferrin, ferritin and serum TfR levels. Those found to be anaemic were compared with seven age-matched subjects with iron deficiency anaemia (IDA) and 24 age-matched children without signs of anaemia or inflammation. Of the 63 patients with IBD, 26 had anaemia. Based on ferritin levels and MCV indices, anaemia was classified as IDA in 11 patients and as anaemia of chronic disease (ACD) in 15 patients. Mean serum TfR level in normal controls was 3.5 mg/l (range 1.2–8.2 mg/l). Mean (±SD) serum TfR levels were significantly lower in the IBD patients with ACD (5.3 ± 2.3 mg/l) than in the IBD patients with IDA (8.2 ± 3.1 mg/l) (P < 0.05). Serum TfR levels above 5 mg/l identified 10/11 IBD patients with IDA. The calculated TfR/ferritin ratio was 84 (range 17–367) for controls and 133 (range 6.4–1840) for IBD patients. A cut-off level of 350 (91% sensitivity, 100% specificity, 100% positive predictive value, 98% negative predictive value) was established for the diagnosis of IDA in IBD. Conclusion The results suggest that serum transferrin receptor is a useful parameter for the diagnosis of iron deficiency in inflammatory bowel disease, in particular, the transferrin receptor/ferritin ratio with a cut-off level ≥350. Received: 1 June 1999 / Accepted: 16 February 2000     

Comparative Assessment of Deferiprone and Deferasirox in Thalassemia Major Patients in the First Two Decades-Single Centre Experience

Iron overload is mainly responsible for the morbidity and mortality in patients with beta thalassemia major (TM). Our aim was to compare treatment outcomes with oral iron chelators, deferiprone (DFP), and deferasirox (DFX) in the first two decades on therapy. Seventy patients with TM (mean age ± SD, 7.9 ± 4.2; range 1.5–17 years) attending the pediatric day care unit for regular transfusional support were enrolled in this cross-sectional cohort study. The patients were treated either with DFP at the dose of 75–100 mg/kg/d in three divided doses after food or DFX at the dose of 25–40 mg/kg/d as single dose before food. Mean serum ferritin (±SD) was lower in patients below 10 years (n = 44) at 1283 (±600) ng/mL when compared with patients ≥10 years (n = 19) at 1546 (±589) ng/mL. There was no significant difference in mean serum ferritin (±SD) level in patients receiving DFP (1360 ± 589) versus DFX (1260 ± 641) in this cohort, P > 0.05. 67% of the patients had Vitamin D deficiency (<50 umol/L). Our results show comparable efficacy of DFP and DFX with regards to iron chelation as estimated by serial serum ferritin levels; however, MRI T2* values were higher in the DFP-treated patients compared to DFX treatment.     

Magnesium therapy in birth asphyxia

Objective: Glutamate plays a critical role in the hypoxic ischaemic neuronal death. Two mechanisms of glutamate-induced neuronal death have been identified. One is rapid cell death that occurs in minutes and the second is delayed cell death that occurs over hours and is initiated principally by the activation of the N-methyl D-Aspactate (NMDA) receptor. Magnesium (Mg) is an NMDA receptor blocker. Systemic administration of Mg after a simulated hypoxic ischaemic insult has been shown to limit neuronal injury in several animal models. However, before embarking on to the use of Mg for neuronal protection in the human neonate, it is important to study the safety and side effects of Mg administration.Methods: Forty terms, appropriate for gestational age babies with severe birth asphyxia (1 min Apgar score <3 and 5min Apgar score <6), were randomly assigned to either the study group or the control group. Infants in both groups were treated as per unit protocol except that babies in the study group received intravenous injection of magnesium sulphate 250 mg/kg within half an hour of birth, and subsequently 125 mg/kg at 24 and 48 hours of life.Results: The mean cord blood serum Mg levels were 0.78 (±0.047) mmol/L in the control group and 0.779 (±0.045) mmol/L in the study group. The serum Mg levels at 3, 6, 12, 24, 48 and 72 hours of life were 1.87 (±0.6), 1.65(±0.059), 1.468 (±0.91), 1.881 (±0.053), 1.916 (±0.053) and 1.493 (±0.084) mmol/L respectively in the study group. All these values were significantly higher than those obtained in the control group (p<0.001). No significant alterations in heart rate, respiratory rate, oxygen saturation and mean arterial pressure were seen, following magnesium infusion with either 250 mg/kg or 125 mg/kg dose. The serum Mg levels in the study group ranged between 1.493 (±0.084) and 1.916 (±0.053) mmol/L, which are considered to be in the neuroprotective range.Conclusion: Injection MgSO₄ administered in a dose of 250 mg/kg and 125 mg/kg as an intravenous infusion is safe, and the Mg levels obtained are in the range considered to be neuropropective.     

Reference values of serum transferrin receptor (sTfR) and sTfR/log ferritin index in healthy children

The aims of this study were to determine appropriate reference ranges for serum transferrin receptor (sTfR) and sTfR/log ferritin (sTfR-F index) in healthy children and their relationship with iron parameters, erythropoiesis, and other conditions presented by the subject. A total of 902 children with normal iron status, aged 1–11 years, were included in a cross-sectional study. A physical examination was conducted and z-score of body mass index (zBMI) obtained. Complete blood count, iron biomarkers, erythropoietin, C-reactive protein, sTfR, and sTfR/log ferritin were determined. Linear multiple regression was applied to identify the factors that determined sTfR and sTfR-F index variability. Mean values for sTfR and sTfR-F index were 1.22 ± 0.28 mg/L (95% confidence interval [CI]: 1.2–1.23) and 0.87 ± 0.25 (95% CI: 0.85–0.88). The reference intervals (2.5th to 97.5th percentiles [P_2.5–P_97.5]) were 0.78–1.9 mg/L and 0.49–1.46, respectively. sTfR and sTfR-F values decreased with age (P <.03 and P <.0001, respectively). No changes were observed with sex. Changes in sTfR and sTfR-F index were consistent with ferritin and erythropoietin variations. Iron biomarkers, erythropoietin, and zBMI predicted 19% and 18.1% of the sTfR and sTfR-F index variability. The results provide reference ranges for sTfR and sTfR-F index in healthy children for clinical use in the assessment of body iron status. Both biomarkers are predicted by iron parameters, erythropoietin, and zBMI.     

Characterization of the beta-adrenergic receptor in isolated human fetal lung type II cells.

Functioning of the beta-adrenergic response system is important for successful transition of the neonate from fetal life to breathing air. We characterized the beta-adrenergic receptors on human fetal lung type II cells, the cell type responsible for many pulmonary responses sensitive to beta-adrenergic stimulation. Type II cells were isolated from human fetal lung explants, and membrane particulates prepared from these cells were used for radioligand binding studies. 125I-iodocyanopindolol, a specific beta-adrenergic antagonist, bound to a single class of saturable, high-affinity binding sites on type II cell membranes with a receptor concentration of 78 +/- 9 fmol receptor/mg membrane protein, a kd of 79 +/- 18 nM, and 958 +/- 120 receptors per cell. Binding was stereoselective with l-propranolol binding with higher affinity than the inactive d-isomer. The binding site had the characteristics of a beta 2-adrenergic receptor. The order of potency of beta-adrenergic agonists was isoproterenol greater than epinephrine much greater than norepinephrine. The beta 2-selective antagonist ICI 118,551 competed for a single class of high-affinity sites. Agonist binding affinity was reduced in the presence of guanyl nucleotides, consistent with receptors coupled to guanine nucleotide binding proteins. beta-Adrenergic agonists also stimulated adenylyl cyclase in these membrane preparations. 125I-iodocyanopindolol binding to membranes prepared from human fetal lung fibroblasts indicated fewer receptors (404 +/- 68) than were present on type II cells. Work by others has suggested a difference in lung function and lung beta-adrenergic receptor concentration between males and females.(ABSTRACT TRUNCATED AT 250 WORDS)     

STUDY OF INTERMITTENT INTRAVENOUS DEFERRIOXAMINE HIGH-DOSE THERAPY IN HEAVILY IRON-LOADED CHILDREN WITH β-THALASSEMIA MAJOR POORLY COMPLIANT TO SUBCUTANEOUS INJECTIONS

The authors tested the efficacy and safety of intermittent high doses of iv deferrioxamine (DFX) on a twice-weekly basis through an externalized venous catheter on 14 thalassemic children who were heavily iron-loaded and poorly or noncomplaint to subcutaneous DFX. The main reasons for their noncompliance were resistance of the child because of severe local reactions or more than one family member affected, with very high burden on the mother to look after all the affected children. There were 9 males and 5 females and their age range was 7–13 years (mean 10.93 ± 1.9 years). All patients were given a 48-h continuous iv infusion of DFX 200–240 mg/kg/day (approximately 10 mg/kg/h) every 2 weeks, combined with subcutaneous 10-h infusion of DFX 3 days/week. One month after the start of the intermittent high-dose DFX program, the 24 h urinary iron excretion was 29.1–1.50 mg/kg/24 h (mean 69.7 ± 32.5 mg/kg/24 h). These values dropped significantly to 29–53 mg/kg/24 h (mean 39.8 ± 7.9 mg/kg/24 h) 1 year after the study (p <. 004) and remained almost the same over the second year (mean 39.07 ± 6.58 mg/kg/24 h). Serum ferritin levels markedly elevated before the start of high-dose chelation fell steadily during iv high-dose DFX therapy. Mean values were 6215.5 ± 578.3, 3971.5 ± 321.6, 2507.2 ± 131.2, and 1866.5 ± 110 ng/mL at 0, 6, 12, and 24 months, respectively. No serious side effects were reported. Intermittent high-dose DFX therapy combined with 3 days of subcutaneous DFX is safe and effective in reducing iron stores and improving the compliance of these heavily iron-loaded thalassemic children.     

一氧化氮和一氧化氮合酶与慢性病贫血

目的测定慢性病贫血(anemia of chronic disease,ACD)患儿血清中一氧化氮(NO,ni-tric oxide)、可诱导型一氧化氮合酶(iNOS,inducible nitric oxide synthase)及血清铁蛋白(Fn,ferritin)浓度,以探讨三种物质的变化及它们在ACD中的作用机制,为ACD的防治提供实验依据。方法采用硝酸还原酶法和酶联免疫吸附法分别测定ACD患儿30例、健康对照组儿童21例血清中NO、iNOS及血清铁蛋白含量。结果①ACD组血清中NO浓度为157.13±28.75(μmol/L),健康对照组儿童血清中NO浓度为33.97±6.79(μmol/L),ACD组明显高于健康对照组(P<0.01),且与贫血程度呈正相关、与Hb含量成负相关(r=-0.66);②ACD组和健康对照组儿童血清中iNOS活力分别为30.66±8.70(U/ml)和9.58±3.72(U/ml),ACD组高于健康对照组,两者比较有显著性差异(P<0.01);③ACD组血清中iNOS活力与N0含量成正相关,相关系数为0.873;④ACD组血清中Fn均值为311.77±73.56(ng/ml),健康对照组儿童血清中Fn均值为31.82±13.80(ng/ml),ACD组高于健康对照组(P<0.01)。结论NO在ACD的发病中可能起重要作用,而NO主要是在iNOS的诱导下产生。ACD组中N0及诱导型一氧化氮合酶与血红蛋白含量成负相关,与贫血程度呈正相关,从而提示使用iNOS抑制剂或可抑制NO的产生,为临床治疗ACD提供新的途径。