Preparation and Identification of scFv and bsFv against Transferrin Receptor

To obtain single chain variable fragment （scFv） and bivalent single chain variable fragment （bsFv） against transferrin receptor, up-stream and down-stream primers were designed according to the complementary sequences of FR1 region of variable heavy （VH） and FR4 of variable light （VL）, respectively, which contained inter-linker G4S and the restriction endonuclease SfiI, AscI and NotI. Two pieces of scFv fragments were first amplified through PCR and then inserted into plasmid pAB1, which could express scFv protein once induced by IPTG in the host bacteria. To express scFv and bsFv, E. coli TG1 was cultured in LB broth and was induced by IPTG. The restriction enzyme digestion map and DNA sequencing demonstrated that scFv and bsFv genes were successfully inserted into the expression plasmid. SDS-PAGE and Western blotting revealed the protein band at 35kD and 60kD, which were consistent with the molecular weight of scFv and bsFv respectively. Flow cytometry showed that scFv and bsFv harbored the specific binding activity with TfR expressed in various tumor cells, and the avidity of bsFv was higher than that of the parent scFv.     

和田地区维、汉族老年居民血清生化指标的测定

目的:探讨新疆和田地区不同民族同年龄段老年居民血清钙(Ca)、磷(P)、镁(Mg)、铁(Fe)、转铁蛋白(TRF)、碱性磷酸酶(AKP)等生化指标的差异。方法:对186例60～79岁维吾尔族(维族)和汉族老年人血清Ca、P、Mg、Fe等水平进行了测定,比较两民族间各生化指标的差异。结果:汉族血清Ca、P、Mg、Fe水平明显高于维族(P<0.01～0.001),两民族血清TRF、AKP水平差异无统计学意义(P>0.05);汉族女性血清Ca、P、Mg、Fe水平明显高于维族(P<0.05～0.001),汉族男性血清P、Fe水平明显高于维族,AKP水平明显低于维族(P<0.05～0.001);汉族女性血清P、Mg、AKP、TRF水平明显高于男性(P<0.05～0.001),维族男性血清Fe水平明显高于女性(P<0.05)。结论:新疆和田地区同年龄段维族和汉族老年居民血清Ca、P、Mg、Fe生化指标的差异可能和两民族居民不同生活习惯有关。     

糖尿病肾病的早期实验室诊断

目的　探讨尿转铁蛋白 (Tf)、微量白蛋白 (m Al B)和尿 N -乙酰 -β- D-氨基葡糖苷酶 (NAG)作为糖尿病肾病早期诊断实验室指标的意义。　方法　 Tf和 m Al B用免疫透射比浊法、NAG用终点法检测 ,Jaffer速率法测尿肌酐。　结果　尿蛋白定性阴性的糖尿病 (DM)患者尿 Tf、m Al B及 NAG三项指标较对照组增高 (P<0 .0 1) ,且尿蛋白阴性的 DM患者与尿蛋白阳性的 DM患者之间三项指标的差异有显著性 (P<0 .0 1)。　结论　 Tf、m Al B、NAG三项指标联合检测是早期诊断糖尿病肾病的灵敏、准确、简便的方法。     

1,25二羟维生素D3对人淋巴细胞免疫功能的调节作用

通过淋巴细胞增殖试验、混合淋巴细胞反应及分析淋巴细胞表面IL-2R 和TfR 表达等研究了1.25-(OH)_2D_3对人淋巴细胞的免疫调节作用。结果表明,1,25-(OH)_2D_3对PHA 诱导的淋巴细胞增殖有抑制作用,IC_(50)为19.1nmol/L 外源性IL-2可部分逆转这种作用;低浓度的1,25-(OH)_2D_3能显著增强MLR 诱导的细胞增殖;在由PHA 和MLR 诱导的淋巴细胞表面IL-2R 和TfR 表达中,对TfR 的表达呈抑制作用,对IL-2R 的表达无影响。     

DNA flow cytometry of human breast carcinomas and its relationship to transferrin and epidermal growth factor receptors

The expression of transferrin and epidermal growth factor receptors in breast carcinomas, as detected by immunohistochemistry, has been compared with DNA ploidy and S-phase content of the same tumours as determined by DNA flow cytometry of fixed, paraffin embedded tissue, and with tumour differentiation. Good correlations have been found between DNA ploidy, S-phase content and differentiation. The expression of transferrin receptor appears to relate to DNA ploidy, but only to a limited extent to S-phase content, indicating that in breast carcinomas immunoreactive transferrin receptor may not be directly related to proliferation. The presence of epidermal growth factor receptor shows a close correlation with high S-phase content, but only a lesser association with DNA ploidy, and no correlation with tumour differentiation. DNA flow cytometry provides a more reliable method of assessing the relationship of such growth factor receptors in breast carcinomas to cell proliferation, than that obtained from more subjective tumour grading criteria.     

HFE based re‐evaluation of heterozygous hemochromatosis

Homozygosity for the C282Y mutation in the HFE gene is strongly associated with hereditary hemochromatosis. More than one subject out of 10 in the general population is a heterozygote for the C282Y mutation. In this study, we address whether or not conclusions drawn from HLA‐based family studies regarding the expression of heterozygous hemochromatosis are applicable to C282Y heterozygotes. The correlation between HLA‐inferred and HFE genotypes and the variation of serum iron tests according to HFE genotype and other factors were studied in persons from well‐characterized hemochromatosis pedigrees. Subjects were tested for both C282Y and H63D mutations. The following factors were studied: age, sex, alcohol consumption, body mass index, liver function tests, serum lipids and glucose, serum iron, transferrin saturation, and ferritin. HLA‐inferred heterozygotes were C282Y heterozygotes in only 70% and compound heterozygotes (i.e., heterozygotes for both C282Y and H63D) in 20%. C282Y heterozygotes did not differ from wild type homozygotes in terms of serum iron tests. Only compound heterozygotes presented with slightly increased transferrin saturation. On the other hand, increased serum ferritin was strongly associated with overweight or lipidic or glucose abnormalities. C282Y heterozygotes selected from family studies do not have greater serum iron tests than wild type homozygotes, except for compound heterozygotes, and therefore should not require special followup. The discovery of abnormal iron tests in a C282Y heterozygote should lead to workup for other causes of iron overload. © 2002 Wiley‐Liss, Inc.     

Transferrin in seminal plasma and in serum of men: its correlation with sperm quality and hormonal status

Transferrin concentrations in the seminal plasma and in serum were measured and correlated with sperm quality (concentration, motility and morphology) and hormonal status (FSH, LH and testosterone) of 75 men aged from 21 to 46 years. A significant positive correlation was found between the seminal plasma concentration of transferrin and the sperm concentration (r = 0.69, P less than 0.0001) and motility (r = 0.39, P less than 0.0001). No other correlations were found. These data confirm that seminal plasma levels of transferrin can be used as a reliable index of sperm quality, and possibly as a Sertoli cell marker.     

Pulmonary alveolar macrophages in patients with sarcoidosis and hypersensitivity pneumonitis: Characterization by monoclonal antibodies

Using a panel of monoclonal antibodies (MoAbs), the frequency of cells bearing Class I and Class II major histocompatibility complex (MHC) determinants, transferrin receptor (TR) sites, and interleukin-2 receptors (IL-2R) has been evaluated on pulmonary alveolar macrophages (PAM) recovered from the bronchoalveolar lavage (BAL) fluid of 21 patients with pulmonary sarcoidosis (including 11 cases with active sarcoidosis and 10 cases with inactive disease), 8 patients with hypersensitivity pneumonitis (HP), and 6 normal non-smoking volunteers. When the frequency of Class II DR-positive cells was considered, 64.3% of control PAM expressed HLA-DR products. No statistically significant differences were observed between controls and sarcoid patients, while HP patients showed an enhanced proportion of DR⁺ PAM with respect to normal PAM (P<0.05). On the contrary, the frequency of PAM expressing HLA-DQ molecules was higher in both active sarcoidosis and HP patients with respect to patients with inactive sarcoidosis and normal subjects (P<0.001). A statistically significant increase in Class I antigen-positive PAM has been demonstrated in HP patients as compared to controls (P<0.05). Active sarcoid patients showed a higher number of PAM-bearing TR sites than controls and other groups of patients considered (P<0.001). An increase in the percentage of IL-2R-positive PAM has been demonstrated in active sarcoidosis (P<0.001). Our data suggest that (1) PAM of patients with the above-considered interstitial lung diseases are in a state of activation and exhibit structures which play a crucial role in antigenic recognition by T lymphocytes, such as HLA-DQ molecules; (2) the presence of TR in PAM of patients with active sarcoidosis could be related to a more advanced differentiation stage of these cells and/or to particular functional properties; and (3) a direct role of the IL-2/IL-2R system in the interaction between T cells and monocytes in sarcoid lung is crucial. Besides representing an additional parameter which differentiates BAL features of sarcoidosis from those of HP patients, these results could represent a useful tool in the evaluation of the macrophagic component of alveolitis by the BAL.     

Involvement of transferrin and transferrin receptors in human natural killer effector:target interaction

In this current study one of the determinants of natural killer cell specificity in immunosurveillance against cancer, may be the recognition of transferrin receptors on neoplastic cells by the NK effectors. Human transferrin, when saturated with iron (FeTf), was found to inhibit human natural killer (NK) activity against K562 tumor cells, if included in assay mixtures at physiologically relevant levels. Whereas both FeTf and iron-free transferrin (ApoTf) inhibited initial conjugate formation at the level of the target cell, only FeTf inhibited NK cytolytic activity, as judged by release of chromium from the targets. This suggested a functional role for FeTf on either NK or tumor cells. When either targets or effector lymphocytes were pre-incubated with FeTf, inhibition of killing was strongest when the targets were first exposed to FeTf. The evidence suggested that NK-associated transferrin mediated the interaction with target cells through free target-associated transferrin receptors. The finding that rabbit anti-human transferrin antibody (RaHTf) inhibited killing, when reacted with effector lymphocytes but not with target cells, supported this hypothesis.     

缺铁合并感染儿童铁剂治疗前后血清可溶性转铁蛋白受体及转铁蛋白的变化

目的探讨血清可溶性转铁蛋白受体(sTfR)、转铁蛋白(Tf)在缺铁合并急性感染儿童(IDAI)口服铁剂治疗前后的变化规律.方法将病例分成IDAI组、单纯缺铁性贫血(IDA)组及IDAI治疗组.IDAI组给口服铁剂3w.采用速率散射免疫比浊法,测定初诊时及治疗3w后患儿血清sTfR、Tf、铁蛋白(SF)水平.部分病例采用常规铁染色观察骨髓储存铁.结果 IDAI组和IDA组患儿sTfR、Tf均显著高于对照组(P<0.01),这两组间无显著差异(P>0.05),IDAI患儿经治疗后血色素(Hb)升高但尚未正常时,sTfR、Tf已降至对照组水平,治疗前后差异显著(P<0.01).结论 sTfR、TF对诊断早期铁缺乏特异,敏感,测定结果不受感染因素干扰,是临床诊断早期缺铁合并感染儿童,指导铁剂治疗及疗效监测的可靠指标.