Methodik und Anwendung des Radioimmunoassays

1. Einleitung

2. Tracerdarstellung

3. Geuinnung von Antiseren

4. Methoden zur Trennung von freier und antikörpergebundener Radioaktivität

5. Analysengang

6. Spezifität

7. Empfindlichkeit

8. Anwendungsbeispiele

9. Literatur     

磁粒子成像示踪剂的研究进展

磁粒子成像是基于功能和断层影像技术检测磁性纳米粒子空间分布的示踪方法, 具有正向的对比信号、 较低的组织背景、 无限的组织穿透深度、 非侵入性成像以及无电离辐射等优点, 是近年来一种很有前途的生物医学成像技术. 磁粒子成像信号是通过在无场点切换磁性纳米粒子的磁自旋矢量来产生的. 磁粒子成像的灵敏度和空间分辨率都高度依赖于作为磁粒子成像示踪剂的磁性纳米粒子本身的磁性能, 因此目前的研究主要集中在磁性纳米粒子的设计和合成上. 本文重点介绍了磁粒子成像示踪剂的最新研究进展, 总结了可作为磁粒子成像示踪剂的磁性纳米粒子的种类、 合成方法、 性能以及生物医学应用, 以期为磁粒子成像的未来研究提供参考.     

Иследоваиие Иследоваиие иоверхиостеӥ

Die zunehmende Industrialisierung der landwirtschaftlichen Production bei höheren Qualitätsanforderungen verlangt objective und hochempfindliche Kontrollverfahren.

Zur zerstörungsfreien Ermittlung innerer Qualitätsmängel an Früchten, z.B. Kartoffelknollen, können lichtoptische Verfahren wegen der starken Streuung nicht umfassend eingesetzt werden. Deshulb wurde unter Einsatz weicher Gammastrahlung (²⁴¹ Am) versucht, “trockene” Hohlstellen, insbesondere bedingt durch Hohlherzigkeit, in Kartoffelknollen zu erkennen. Es konnte gezeigt werden, daβbei einem Erkennungsfehler von etwa 13% diese Mängel (ab ca. 5 mm Durchmenser) zu erkennen sind, auch wenn die Knollen nur in einer durch die Knollenmitte verlaufenden Ebene durchstrahlt werden.     

Computerprogramm zur interaktiven Auswertung von 15N-tracerkinetischen Stoffwechselexperimenten

The theoretical concept of the computer program is based on the compartment theory for the 3-pool model using single pulse administration of the tracer. The code estimates the model parameters by means of the non-linear method of least squares fit under steady state conditions. Furthermore the parameters of the protein metabolism are calculated. The program works interactively and allows reading and modifying the experimental ¹⁵N tracer data via terminal and controlling the program.     

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Studies on the workability of precise seeders by means of labelling methods has been possible due to the solution of the following problems: labelling of seeds, radiation collimation of labelled seeds being sown, elaboration of measuring and registering systems as well as processing systems of a measuring signal. The developed method allows for precise, quick and fully objective evaluation of the studied seeders to be done under natural conditions.     

Methodik und Ergebnisse von Tracerexperimenten über katalytische Reaktionen von Kohlenwasserstoffen

Tracermethoden können wichtige Beiträge zur Aufklärung katalytischer Kohlenwasserstoffreaktionen liefern. In dieser Arbeit werden einige Ergebnisse mehrjähriger Untersuchungen mit ¹⁴C-markierten Verbindungen zusammenfassend dargestellt. Es wird speziell auf Benzenbildungsreaktionen bei der Leichtbenzin-Reformierung und auf Reaktionsmechanismen bei der Isomerísierung von C₈-Aromaten eingegangen.     

Ein Vergleich zwischen radioaktiver Markierung und Indikator-Aktivierungsanalyse bei der Messung von Verweilzeitspektren

An VK-Z-Rohren zur Herstellung von Polyamid wurden Verweilzeitspektren mit der Methode der radioaktiven Markierung und der Methode der Indikatoraktivierungsanalyse gemessen. Die nach den beiden Methoden ermittelten Verweilzeitspektren werden miteinander verglichen. Die Übereinstimmung der Verweilzeitspektren wird durch Gegenüberstellung der statistischen Momente und durch einen Test nach Kolmogoroff-Smirnov geprüft. Es wird der experimentelle Aufwand beider Verfahren diskutiert und eine Fehlerabschätzung durchgeführt.     

The effect of resistant starches on fat oxidation in healthy adults as measured by a 13CO2-breath test

A resistant starch (RS) mixture (MIX) consisting of fibre of potatoes (FP) and wrinkled pea starch (WPS), and high amylose maize starch (HAMS) were supplemented in adults to evaluate their effects on fat oxidation by means of a ¹³CO₂-breath test. Sixteen subjects received a regular diet either without or with the supplementation of MIX and HAMS in randomised order. After administration of a [U-¹³C]algal lipid mixture, exhaled air was collected over 14?h in 0.5- and 1-h intervals. The ¹³C abundances were measured by nondispersive infrared spectroscopy. In comparison to the dry run (DR), supplementation with MIX and with HAMS increased the cumulative percentage dose recovery: (DR: 16.7?%, MIX: 16.9?%, HAMS: 18.0?%), but without statistical significance. The colonic degradation of MIX and HAMS to short-chain fatty acids tends to lower the formation of carbohydrate-derived acetyl-CoA and contributes to a postprandial lipid oxidation increase by using fat-derived acetyl-CoA as a compensatory fuel source.     

Deuterium dilution technique for body composition assessment: resolving methodological issues in children with moderate acute malnutrition

Childhood malnutrition is highly prevalent and associated with high mortality risk. In observational and interventional studies among malnourished children, body composition is increasingly recognised as a key outcome. The deuterium dilution technique has generated high-quality data on body composition in studies of infants and young children in several settings, but its feasibility and accuracy in children suffering from moderate acute malnutrition requires further study. Prior to a large nutritional intervention trial among children with moderate acute malnutrition, we conducted pilot work to develop and adapt the deuterium dilution technique. We refined procedures for administration of isotope doses and collection of saliva. Furthermore, we established that equilibration time in local context is 3?h. These findings and the resulting standard operating procedures are important to improve data quality when using the deuterium dilution technique in malnutrition studies in field conditions, and may encourage a wider use of isotope techniques.     

Measurement of total Zn and Zn isotope ratios by quadrupole ICP-MS for evaluation of Zn uptake in gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss)

This study evaluates the potential use of stable zinc isotopes in toxicity studies measuring zinc uptake by the gills of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss). The use of stable isotopes in such studies has several advantages over the use of radioisotopes, including cost, ease of handling, elimination of permit requirements, and waste disposal. A pilot study using brown trout was performed to evaluate sample preparation methods and the ability of a quadrupole inductively coupled plasma mass spectrometer (ICP-MS) system to successfully measure changes in the ⁶⁷Zn/⁶⁶Zn ratios for planned exposure levels and duration. After completion of the pilot study, a full-scale zinc exposure study using rainbow trout was performed. The results of these studies indicate that there are several factors that affect the precision of the measured ⁶⁷Zn/⁶⁶Zn ratios in the sample digests, including variations in sample size, endogenous zinc levels, and zinc uptake rates by individual fish. However, since these factors were incorporated in the calculation of the total zinc accumulated by the gills during the exposures, the data obtained were adequate for their intended use in calculating zinc binding and evaluating the influences of differences in water quality parameters.