Lactation modifies stress-induced immune changes in laboratory rats.

Lactation and stressor exposure both influence the activity of the immune system, but the interaction of both factors on the immune defense is poorly understood. The aim was therefore to investigate in lactating Long-Evans rats the effect of social stress on aspects of cellular immunity in the blood and mesenteric lymph nodes (MLN). Acute social stress (2h) was induced in lactating and non-lactating female intruders using a confrontation model that yielded into social defeat and increased plasma corticosterone concentrations. Stress as well as lactation had marked effects on the immune system. Acute social stress caused granulocytosis, reduced lymphocyte proliferation, and cytokine production in the blood, but had no significant effects in MLN. In the blood of lactating rats, increased numbers of granulocytes and enhanced phagocytosis, but decreased B cell numbers and reduced IL-2 production was observed. However, in MLN both lymphocyte proliferation and monocyte numbers were increased in lactating rats. The effect of stress on the immune measures was often similar in lactating and non-lactating females, but a few important differences were evident: Only non-lactating animals showed an increase in blood granulocyte numbers and a decrease in IL-2 production in response to stressor exposure. Thus, during lactation, a neuroendocrine status may exist which impedes stress-induced modulations at least of some immune parameters

Optical Imaging

Optical Coherence Tomography (OCT)We describe the fundamental concept of optical coherence tomography (OCT) and discuss the two main working principles time domain OCT and frequency domain OCT. Then, we review extended functionalities including spectrally and polarization-resolved OCT as well as Doppler-OCT and show concepts for contrast enhancement. Based on these fundamentals, we demonstrate the potential of OCT for small animal imaging on the basis of exemplary studies on retinal imaging and lung imaging.Optoacoustic ImagingThis chapter deals with the fascinating topic of optoacoustic imaging, a recent powerful addition to the arsenal of in vivo functional and molecular small animal imaging. Due to its hybrid nature, involving optical excitation and ultrasonic detection, optoacoustics overcomes the imaging depth limitations of optical microscopy related to light scattering in living tissues while further benefiting from the compelling advantages of optical contrast. To this end, optoacoustic imaging has been shown capable of delivering multiple types of imaging contrast (structural, functional, kinetic, molecular) within a single imaging modality. It can further deliver images with high spatiotemporal resolution that rivals performance of other well-established whole-body imaging modalities. As such, optoacoustics can play a vital role in biomedical research, from early disease detection and monitoring of dynamic phenomena noninvasively to accelerating drug discovery.Optical ProbesThis chapter is devoted to the properties and application of fluorescence dyes as probes for optical imaging. A variety of agents have been described to date, including nontargeting dyes, vascular agents, targeted conjugates, activatable dyes, and sensing probes. The major classes encompass polymethine dyes and xanthenes dyes, both of which are commercially available in broad variations. Addressing the purpose of optical animal imaging, the most relevant parameters to apply such probes are discussed, thereby supporting the reader in choosing reasonable imaging probes and in preparing bioconjugates for his studies

Neue Konzepte für die spektroskopische und phasenaufgelöste optische Kohärenztomographie

Die Optische Kohärenztomographie (Englisch Optical Coherence Tomography - OCT) ist ein bildgebendes, tomographisches Messverfahren. In der OCT werden breitbändige Messungen mit einem Interferometer durchgeführt, deshalb kann sowohl ein Spektrum, als auch die Phaseninformation aus dem OCT Signal berechnet werden. Bei der spektroskopischen OCT kann die zusätzliche spektrale Information genutzt werden, um den Kontrast zu erhöhen. In dieser Arbeit wurde die spektroskopische OCT mit Mustererkennungsverfahren kombiniert und eine Kontraststeigerung in gewebeimitierenden Phantomproben und Knorpelproben nachgewiesen. Die Phaseninformation kann dazu genutzt werden um topographische Höhenkarten einer Probenoberfläche mit hoher Genauigkeit zu erzeugen. In der vorliegenden Arbeit wurde ein neuartiger Algorithmus zur Phasenentpackung implementiert, der es erlaubt, auch Probenstrukturen einer Größenordnung zu erfassen, die sich mit herkömmlichen Verfahren nicht vermessen lassen

Analysing Territorial Policies in Western Europe. The Case of France, Germany, Italy, and Spain

International audienc