超顺磁性氧化铁Resovist标记神经干细胞的实验研究

目的研究超顺磁性氧化铁（superparamgnetic iron oxides，SPIOs）标记神经干细胞及其生物学特性．方法：神经干细胞培养、传代和诱导分化；Resovist（一种SPIOs）标记神经干细胞。制备磁标记神经干细胞；利用免疫细胞化学、透射电镜和Prussian blue染色等方法对磁标记神经干细胞生物学特性进行研究。结果：在原代及传代细胞中有Nestin阳性细胞即神经干细胞．血清诱导下，神经干细胞可分化为GFAP、NF200阳性细胞．Resovist与神经干细胞共同孵育后，透射电镜及Prussian blue染色显示胞浆中含有铁颗粒，Resovist也可以随细胞的分裂增殖而传到子代细胞中。随Resovist浓度的增高（5．6μg／ml-11．2μg/ml），Resovist对神经干细胞存活、分化能力的影响无显著性差异（P〉0．05）．当Resovist的浓度大于22．4μg／ml时。Resovist影响其存活和分化（P〈0．05）。结论：本实验利用Resovist作为磁标记探针，对神经干细胞进行成功磁标记，为进一步利用核磁共振（MRI）对神经干细胞活体追踪奠定实验基础。     

Magnetic nanoparticle labeling of mesenchymal stem cells without transfection agent: cellular behavior and capability of detection with clinical 1.5 T magnetic resonance at the single cell level.

The purpose of this work was to evaluate the efficacy of labeling human mesenchymal stem cells (hMSCs) by ionic superparamagnetic iron oxide (SPIO) without a transfection agent and verifying its capability to be detected with clinical 1.5 T magnetic resonance (MR) at the single-cell level. Human hMSCs were incubated for 24 h with an ionic SPIO, Ferucarbotran. The labeling efficiency of hMSCs was determined by iron content measurement spectrophotometrically, and the influence of labeling on cell behavior was ascertained by examination of cell viability using the trypan blue exclusion method, cell proliferation analysis using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, mitochondrial membrane potential (MMP) change, differentiation capacity, and reactive oxygen species (ROS) production measured by dichlorofluorescein diacetate (DCFDA) fluorescent probe. Labeled hMSCs were scanned under 1.5 T MRI with three-dimensional (3D) and two-dimensional (2D) T(2)-weighted gradient echo (GRE) pulse sequences. Human hMSC labeling without transfection agent was efficient. The iron content in hMSCs was 23.4 pg Fe/cell. No significant change was found in viability, proliferation, MMP change, ROS production, or differentiation capacity. About 45.2% of the hMSCs could be detected using 1.5 T MRI at the single cell level with 3D GRE and four repetitions.     

异搏定区域动脉灌注在阻止急性胰腺炎重症化治疗中的作用

目的探讨钙拮抗剂异搏定区域动脉灌注在阻止急性胰腺炎重症化治疗中的作用。方法45例轻型急性胰腺炎患者被随机分为3组常规治疗组、静脉治疗组及动脉灌注组。入院后,常规治疗组采取常规保守治疗;静脉治疗组行合理液体治疗,静脉注射异搏定;动脉灌注组液体补充同时采用持续动脉灌注异搏定1~2周。测定治疗后1、4及7d血清肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、黏附分子-1(ICAM-1)及P-选择素(P-selectin)水平。结果治疗后4、7d,血清TNF-α和P-selectin水平动脉灌注组较静脉治疗组及常规治疗组明显降低(P<0.05);血清IL-1β水平动脉灌注组和静脉治疗组均较常规治疗组明显降低(P<0.05);血清ICAM-1水平动脉灌注组明显低于常规治疗组(P<0.05)。结论持续区域动脉灌注异搏定可能通过减少细胞因子的产生,抑制黏附分子P-selectin和ICAM-1的上调,阻止急性胰腺炎重症化发展。     

HFE codon 63/282 (H63D/C282Y) dimorphism in German patients with genetic hemochromatosis

Abstract: Genetic hemochromatosis (GH) is closely associated with genes of the major histocompatibility complex (MHC) on chromosome 6. Recently, a candidate gene for GH, with structural similarities to MHC class I genes, designated HLA-H and presently named HFE, has been cloned. The HFE gene is localized telomeric to the MHC and several reports have indicated that the HFE gene is mutated in GH patients. In the present study we have analyzed the relationship of HFE gene variants and disease manifestation in GH patients and family members. Fifty-seven patients with GH, 73 family members and 153 healthy blood donors were studied for the amino acid dimorphism at codon 63 (His63Asp=H63D) and codon 282 (Cys282Tyr= C282Y) of the HFE gene. The codon 63 and 282 dimorphism were defined by PCR amplification of genomic DNA samples and restriction enzyme digestion using RsaI/SnaBI for C282Y and Bcll/Mbo 1 for H63D. Ferritin, transferrin serum levels and total iron-binding capacity were determined prior to therapeutic intervention. The Tyr-282 substitution occurred in 53 (93%) of patients compared with 8 (5.2%) of controls (OR=169, P >0.0001). Fifty-one (90%) patients were Tyr-282 homozygous. In contrast, the Asp-63 substitution was present in 5 (8.8%) of the patients compared with 34 (22%) of controls (OR=0.39, P =NS) with none of the patients being homozygous. In Tyr-282 homozygous GH patients serum ferritin levels, transferrin saturation, liver iron and liver iron index were elevated significantly compared to Tyr-282-negative patients, whereas no difference was observed between Tyr/Cys-282 heterozygous and Tyr-282-negative patients.     

Mortality among ferrous foundry workers

Mortality analyses were carried out for 278 male hourly workers who were employed for at least 10 years at a gray iron foundry and who died between January 1, 1970 and December 31, 1981. Statistically significant excess proportional mortality due to non-malignant respiratory disease (SPMR = 177), lung cancer (SPMR = 148), and leukemia (SPMR = 284) was found among the 221 white males. Among nonwhite males there was a significant excess in proportional mortality due to circulatory diseases (SPMR = 143). White males in the Finishing classification experienced a significant excess of proportional mortality due to nonmalignant respiratory disease (SPMR = 279) and lung cancer (SPMR = 179). White males in the Core Room classification experienced an excess of proportional mortality due to nonmalignant respiratory disease (SPMR = 321). Case-control studies demonstrated a significant association between nonmalignant respiratory disease and the Finishing classification after controlling for the effects of age, prior occupations in coal mining or foundries, and smoking. A positive but nonsignificant association between lung cancer and Finishing was also found after controlling for age, prior work history, and smoking in case control studies.     

Assessment of erythropoiesis following renal transplantation

Abstract: Ten patients, who received cadaveric kidneys, were followed for 24 wk with serial measurements of serum erythropoietin (S-Epo), transferrin receptor (S-TfR) and iron variables. The mean pretransplant creatinine clearance was 8.2 (range 0–22) ml/min and the mean haemoglobin (Hb) level was 99±18.6 (range 66–124) g/l. Nine patients demonstrated a gradual increase in S-Epo levels, which reached a peak, and was accompanied by a parallel increase in S-TfR levels with a median lag period of 3 wk between both peaks. Hb correction followed the S-TfR peak after a second lag period (median 7 wk). Elevated S-Epo and S-TfR did not result in correction of anaemia in 1 patient due to impaired graft function. Within 4 months, S-Epo levels reached the normal range while TfR levels were higher than normal. Follow-up of iron status demonstrated the development of iron deficiency in 5 patients, which was corrected spontaneously. Improvement in erythropoiesis after renal transplantation seems to occur by means of expansion of the erythroid marrow, as detected by increasing S-TfR levels, subsequent to a S-Epo peak. This expansion precedes Hb normalization. A nonuraemic environment is probably a prerequisite for the correction of anaemia but not for the increase in S-Epo or S-TfR levels. Iron deficiency may occur after transplantation due to an increase in iron utilization.     

Correlation between soluble transferrin receptor and serum ferritin levels following bone marrow transplantation for thalassemia

Abstract: This study analyzes the serum transferrin receptor (sTfR) levels in a series of 230 ex-thalassemics with a follow-up of 1 to 9 years after bone marrow transplantation (BMT) for homozygous β thalassemia. Ex-thalassemics are individuals, cured of homozygous β thalassemia by BMT, who maintain different degrees of iron overload acquired during the pretransplant period. Both in experimental and clinical conditions, sTfR concentrations have been shown to be a quantitative measure of body iron status. This study was carried out to assess whether the level of sTfR may be of help in determining the extent of iron overload in ex-thalassemics. Patients who received the marrow from their HLA-identical sibling donor heterozygous for β thalassemia, namely heterozygous ex-thalassemics, displayed significantly higher levels of sTfR than patients transplanted from their normal sibling donors (normal ex-thalassemics). This finding suggests that increased erythropoiesis, albeit in part ineffective in heterozygous ex-thalassemics, is responsible for the sTfR increment. Both heterozygous and normal ex-thalassemics had significant lower sTfR levels than their heterozygous (p < 0.003) or normal (p < 0.0001) donors, respectively. These differences may be ascribed to the presence of iron overload in ex-thalassemics in comparison to their normal or heterozygous donors who did not present excess of iron in the body. A significant inverse correlation between sTfR and serum ferritin levels (r = –0.54, p < 0.0001) was found when normal ex-thalassemics were considered. In heterozygous ex-thalassemics, the lack of correlation between these two parameters may be explained by the enhanced erythropoietic activity of individuals with thalassemic trait. These results suggest that the level of sTfR may be a useful indicator of iron overload in normal ex-thalassemics.     

Enhanced Fluid Removal Guided by Blood Volume Monitoring During Chronic Hemodialysis

Fluid overload predisposes chronic hemodialysis patients to cardiovascular disease, a significant cause of morbidity and mortality in these patients. We evaluated the efficacy of monitoring changes in blood volume during routine hemodialysis to detect fluid overload. Intradialytic changes in blood volume were monitored by continuously measuring hematocrit in all 56 patients in a single dialysis unit over 7 weeks. After Week 1, patients were categorized into 2 separate groups depending on their maximum intradialytic decreases in blood volume. In Group 1, 46 of 56 or 82% had greater than a 5% decrease in blood volume while in Group 2, 10 of 56 or 18% had less than a 5% decrease in blood volume. During Weeks 2–7, dialytic fluid removal was intentionally increased in Group 2 patients by 0.80 ± 0.62 L (mean ± SD) or 47 ± 43%. This intervention resulted in a larger (p < 0.02) intradialytic decrease in body weight (2.7 ± 0.9 kg versus 2.0 ± 0.8 kg) and a larger (p < 0.02) intradialytic decrease in blood volume (15 ± 5% versus 4 ± 1%) than experienced during Week 1 with a low incidence of symptoms. We conclude that there is a significant percentage of chronic hemodialysis patients who can tolerate additional fluid removal without hypovolemic symptoms even though they are considered to be at dry weight by routine physical examination and that the identification of these patients can be facilitated by intradialytic blood volume monitoring.