Developmental regulation of type 1 and type 3 interferon production and risk for infant infections and asthma development

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Epoxy-resin injection of the cerebral arterial microvasculature: An evaluation of the limits of spatial resolution in 8 Tesla MRI

The purpose of this study was to quantify the spatial resolution of microscopic arteries on magnetic resonance images acquired at 8 Tesla (T). Techniques similar to those used for standard MRI of the human brain in vivo at 8 T were utilized to generate high-resolution gradient echo (GE) images of a whole postmortem human brain whose common carotid arterial system had been injected with an epoxy-resin. Single slice images, along with summed images of up to 5 contiguous slices, were then compared to color digital photographs detailing the distribution of the arterial system on the surface of the same injected brain. There was excellent MR visualization of the microscopic cerebral arteries down to a spatial resolution of 200 microm. Through the use of an 8 T whole-body MRI scanner and standard GE imaging sequences, microscopic arterial structures can be clearly resolved down to a dimension of 200 microm.     

Role of Relative Changes in Caval Flows for Evaluation of Right Atrial Pressure Shifts Induced by Nitroglycerin

Experiments on cats treated with nitroglycerin showed dynamic relationship between changes in caval venous flows: blood flow increased in the superior vena cava and decreased in the inferior vena cava. Blood pressure in the right atrium either decreased, or increased. No significant changes in total venous return were observed during maximum shifts in right atrial pressure, while contractility of the right ventricular myocardium usually decreased. Our findings suggest that the direction of the right atrial pressure shifts induced by nitroglycerin does not depend on venous return, but is determined by the prevalence of flow changes in the superior vena cava or inferior vena cava.     

Peripheral blood mononuclear cell proliferative responses in the first year of life in babies born to allergic parents

Background Raised peripheral blood mononuclear cells (PBMCs) proliferative responses to food allergens have been demonstrated in children with established atopic dermatitis. Objective In this report we investigate the PBMC proliferative responses to inhalant and food allergens from babies at birth, 6 months and 1 year of age, born to atopic and non-atopic parents. Methods PBMCs, separated by density gradient centrifugation. were cultured for 6 days with autologous plasma and a range of allergens (house dust mite [HDM], cat, grass pollen, tree pollen, betalactoglobulin and ovalbumin). Proliferative responses were measured by the uptake of [³H] thymidine added for the final 18 h of culture. Results At birth, infants born to atopic parents who developed allergic disease by 1 year of age had significantly more positive responses (stimulation index ± 2 with a value of ± 1000 cpm above background) to HDM (P = 0.0091), betalactoglobulin (P= 0.0166) and ovalbumin (P = 0.0035) than newborns who did not develop allergy. Tnfants who developed allergy also had significantly more positive responses to HDM (P - 0.03) and ovalbumin (P = 0.0057) than babies, born to non-atopic parents, who did not develop allergies. At 6 months of age a significant fall in response to HDM (P = 0.003) and cat fur extract (P = 0.006) was seen in infants who developed allergic disease by 1 year of age. A similar pattern was seen for proliferative responses to betalactoglobulin and ovalbumin (P = 0.0006. P= 0.004). Conversely, proliferations to grass and tree pollen extracts increased at 6 months (P = 0.04. P = NS) and 1 year (P= NS. P= 0.01) compared with birth which was significant for infants who did not develop allergic disease. Conclusion Proliferative responses to seasonal allergens increased over the first year of life whilst those to perennial allergens, both inhalant and food, fell. This suggests either the induction of a systemic immune tolerance by perennial exposure to antigens or movement of sensitized cells to target organs where allergen exposure occurs. This process may be independent of the development allergic disease.     

性别、孕周、身长体重指数和日龄对早期新生儿血化学指标的影响

为探讨性别、孕周、身长体重指数和日龄对早期新生儿血化学指标的影响，我们对241例早期新生儿六大类常用血化学指标进行了检测和分析，现报道如下。     

ABO血型基因分型及应用

目的 :研究ABO血型基因分型的意义。方法 :采用聚合酶链反应 序列特异性引物 (PCR SSP)基因定型方法对ABO血型基因定型并观察其基因多态性分布特征和疑难血型检定。结果 :对已知ABO基因的DNA标本进行基因定型 ,证实文中的ABO基因定型方法可靠 ;对 10 4例健康、无血源关系的汉族个体ABO血型基因定型 ,结果与血清学所定表型完全符合 ;并用ABO基因分型技术解决临床输血前血型鉴定、产前胎儿血型鉴定、亲权试验及血清学亚型的正确性验证。结论 :ABO血型基因分型技术可以正确判定ABO血型疑难样本     

脐带血中衍生树突状细胞及其生物学特性的研究

目的　利用脐带血衍生培养树突状细胞 (DC) ,以获得可用于临床治疗的一种新的血细胞制品 .方法　从脐带血中分离单个核细胞 ,联合使用细胞因子GM -CSF、IL - 4和TNF -α在体外诱导和扩增DC ;采用扫描电镜、流式细胞仪 (FACS)和混合淋巴细胞反应 (MLR)试验对脐带血来源的DC进行生物学特性分析 .结果　从 30ml脐血诱导培养 12d后可获得 6 .6× 10 6的DC .扫描电镜观察具有典型的树突状突起 ;FACS分析显示 ,获得的DC细胞群高表达CD1a(90 .6 % )、CD80 (96 .8% )、CD86(84 .8% )和HLA -DR(91.0 % ) ;MLR显示 ,脐带血诱导培养的DC对同种异体的脐带血幼稚型T细胞均具有强烈的激发和促增殖作用 .结论　从脐带血中成功诱导出大量高纯度成熟DC ,为依赖DC免疫治疗的临床应用打下基础     

IL-6和IL-11对脐血CD34+细胞诱导分化为巨核细胞的影响

目的： 探讨白细胞介素－6(IL-6)和白细胞介素－11(IL-11)对脐血CD34+细胞诱导分化为巨核细胞及其产生血小板的影响。方法: 采用免疫磁珠法(MACS)分选8例健康产妇足月顺产的胎儿脐血中CD34+细胞，以含血小板生成素（TPO 50 μg/L）、白细胞介素-3（IL-3 10 μg/L）、干细胞因子（SCF 50 μg/L）的无血清培养基作为对照组，分别添加10 μg/L IL-6、IL-11、IL-6+IL-11作为实验组，培养14 d后观察结果。利用细胞计数仪检测单个核细胞数；流式细胞仪计数培养体系中的CD41+细胞和血小板；用倒置显微镜观察培养体系中的细胞生长情况；用显微镜和流式细胞仪观察凝血酶诱导后的血小板凝集情况。结果: 各实验组单个核细胞数与对照组无明显区别（P>0.05），而CD41+细胞和血小板数量明显多于对照组(P<0.05)。培养第14 d后倒置显微镜下可见实验组中血小板样颗粒物明显多于对照组，而且经凝血酶诱导后有明显血小板凝集。结论: IL-6和IL-11可诱导脐血中CD34+细胞分化为巨核细胞并产生功能性血小板。     

Na+-Ca2+ exchange in the isolated cochlear outer hair cells of the guinea-pig studied by fluorescence image microscopy

The outer hair cell isolated from the guinea-pig was superfused in vitro and the cytosolic calcium concentration ([Ca²⁺]_i) and sodium concentration ([Na⁺]_i) were measured using fluorescence indicators. Under the resting condition, [Ca²⁺]_i and [Na⁺]_i were 91±9 nM (n = 51) and 110±5 mM (n = 12), respectively. Removal of external Na⁺ by replacing with N-methyl-D-glucamine (NMDG⁺) increased [Ca²⁺]_i by 270±79% (n = 27) and decreased [Na⁺]_i by 23±4 mM (n = 6). Both changes in [Ca²⁺]_i and [Na⁺]_i were totally reversible on returning external Na⁺ to the initial value and were inhibited by addition of 0.1 mM La³⁺ or 100 M amiloride 5-(N,N-dimethyl) hydrochloride. Elevation of external Ca²⁺ ions to 20 mM reversibly decreased [Na⁺]_i by 8±6 mM (n = 5). Moreover, the chelation of the intracellular Ca²⁺ with 1,2-bis (2-aminophenoxy) ethane-N,N,N,N-tetraacetic acid (BAPTA) exerted an inhibitory action on the NMDG⁺-induced reduction in [Na⁺]_i. Exposure to 5 mM NaCN for 2 min significantly and reversibly increased [Ca²⁺]_i by 290±37% (n = 5), but did not affect the [Ca²⁺]_i elevation induced by the NMDG⁺ solution. The rise in [Ca²⁺]_i induced by the NMDG⁺ solution was not enhanced by ouabain pretreatment. Addition of ouabain did not alter the [Na⁺]_i. The present results are best explained by the presence of an Na⁺-Ca²⁺ exchanger in cell membrane and indicate that the activity of Na⁺/K⁺ pump is poor in outer hair cells.