Axon swellings produced in vivo in isolated segments of nerves

Within 3–5 hrs after cutting rat and cat sciatic nerves into segments which had no connection with the cell body, club-shaped axon swellings were observed at both ends of the segments. The swollen portion of these axons showed increased histochemical reactions for DPN-diaphorase, lactic dehydrogenase, malic dehydrogenase, succinic dehydrogenase, and protein; the increase lasted for 24–48 hrs after the nerve was cut. The swollen axons were morphologically and histochemically similar to, but never as markedly changed, as those observed in the proximal stumps of severed nerves. The development of axon swellings was prevented by depolarization of the entire segment with KCl; however, if KCl was applied selectively to the stumps of the segment, it appeared to intensify rather than prevent the swelling. It was also noted that the extent of axon swelling was inversely proportional to the length of the segment. These observations suggested that the development and extent of axon swelling was related to the intensity of local injury currents in the tissue. Innerhalb von 3–5 Std nach Zerschneidung des Nervus ischiadicus von Ratten und Katzen in Segmente, die keine Verbindung mit dem Zellkörper besitzen, sind zylinderförmige Axonschwellungen an beiden Enden der Segmente zu beobachten. Der angeschwollene Teil dieser Axone zeigt verstärkte histochemische Reaktionen auf DPN-Diaphorase, Milchsäure-Dehydrogenase, Apfelsäure-Dehydrogenase, Bernsteinsäure-Dehydrogenase und Protein; dieser Anstieg hält 24–48 Std nach der Durchtrennung des Nervs an. Die Axonschwellungen sind sowohl morphologisch als auch histochemisch ähnlich — jedoch niemals in gleich starker Ausprägung — jenen, die in den proximalen Stümpfen von verletzten Nerven beobachtet werden.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47224/1/401_2004_Article_BF00684398.pd

Profiling and imaging of forensic evidence – a pan-European forensic round robin study part 1: document forgery

The forensic scenario, on which the round robin study was based, simulated a suspected intentional manipulation of a real estate rental agreement consisting of a total of three pages. The aims of this study were to (i) establish the amount and reliability of information extractable from a single type of evidence and to (ii) provide suggestions on the most suitable combination of compatible techniques for a multi-modal imaging approach to forgery detection. To address these aims, seventeen laboratories from sixteen countries were invited to answer the following tasks questions: (i) which printing technique was used? (ii) were the three pages printed with the same printer? (iii) were the three pages made from the same paper? (iv) were the three pages originally stapled? (v) were the headings and signatures written with the same ink? and (vi) were headings and signatures of the same age on all pages? The methods used were classified into the following categories: Optical spectroscopy, including multispectral imaging, smartphone mapping, UV-luminescence and LIBS; Infrared spectroscopy, including Raman and FTIR (micro-)spectroscopy; X-ray spectroscopy, including SEM-EDX, PIXE and XPS; Mass spectrometry, including ICPMS, SIMS, MALDI and LDIMS; Electrostatic imaging, as well as non-imaging methods, such as non-multimodal visual inspection, (micro-)spectroscopy, physical testing and thin layer chromatography. The performance of the techniques was evaluated as the proportion of discriminated sample pairs to all possible sample pairs. For the undiscriminated sample pairs, a distinction was made between undecidability and false positive claims. It was found that none of the methods used were able to solve all tasks completely and/or correctly and that certain methods were a priori judged unsuitable by the laboratories for some tasks. Correct results were generally achieved for the discrimination of printer toners, whereas incorrect results in the discrimination of inks. For the discrimination of paper, solid state analytical methods proved to be superior to mass spectrometric methods. None of the participating laboratories deemed addressing ink age feasible. It was concluded that correct forensic statements can only be achieved by the complementary application of different methods and that the classical approach of round robin studies to send standardised subsamples to the participants is not feasible for a true multimodal approach if the techniques are not available at one location

Contractile and histochemical properties of regenerating cross-transplanted fast and slow muscles in the rat

The soleus (SOL) or extensor digitorum longus (EDL) muscles of month-old rats were denervated for 14 days and then cross-transplanted so that the fast muscle was placed into the bed of the slow muscle and vice versa. At 17, 30, 60, and 90 days the transplants were tested for certain contractile and histochemical properties. By 90 days the cross-transplanted SOL showed complete conversion of the full contraction time and nearly complete conversion of the half relaxation time to those of the normal EDL. In contrast, the contraction and relaxation times of the cross-transplanted EDL became considerably slowed, but did not attain the values of the normal SOL. Histochemical staining for ATPase and SDH activity demonstrated similar transformations of fiber types. The degree of transformation of twitch and histochemical characteristics in cross-transplanted muscles was greater than the values reported after cross-innervation of the same muscles. The cross-transplantation model has certain advantages over nerve cross-union experiments because the cross-transplanted muscle is placed in the normal functional environment of the other muscle.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47444/1/424_2004_Article_BF00584286.pd