Cytochemische Unterschiede zwischen Plasmazellen und Myelomzellen

Zusammenfassung Mit cytochemischer Methodik wurde die Aktivität von saurer Phosphatase, bei p_H 7,2 wirksamen Phosphatasen, alkalischer Phosphatase, unspezifischen Esterasen und Aminopeptidase in Knochenmarkausstrichen von 200 Patienten mit verschiedenen Erkrankungen und reaktiven Knochenmarksveränderungen sowie 38 Patienten mit Plasmocytom, darunter ein Fall von Plasmazellenleukämie, untersucht. Normale Plasmazellen zeichnen sich durch deutliche ATPase-Aktivität, eine mäßige Aktivität von saurer Phosphatase und durch schwache Esteraseaktivität aus. Keine Fermentreaktion fand sich bei Verwendung der Substrate Glycerophosphat, Adenosin-5- und Adenosin-3-monophosphat, beim Nachweis der alkalischen Phosphatase, der Aminopeptidase und bei Benutzung von Naphthol-AS-D-chloracetat als Substrat für den Esterasenachweis. Myelomzellen zeichnen sich durch verstärkte Aktivität von saurer Phosphatase und unspezifischer Naphthol-Esterase aus. Die ATPase-Aktivität ist im Vergleich zu normalen Plasmazellen deutlich vermindert oder fehlt völlig.Die mögliche Bedeutung der Befunde wird erörtert.Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

Adenosine receptor density and the depression of evoked neuronal activity in the rat hippocampus in vitro

The relationship between the heterogeneous distribution of A-1 adenosine receptors and the capacity of adenosine to depress neuronal activity was examined in the rat hippocampus. Utilizing autoradiographic techniques, the distribution of A-1 adenosine receptors was assessed by the binding of [3H]cyclohexyladenosine ([3H]CHA) to cryostat sections of rat brain. The apical dendritic region of CA1 showed a differential distribution of adenosine receptors between the stratum radiatum and stratum lacunosum/moleculare. The physiological relevance of this binding difference was studied in the hippocampal slice by examining the capacity of adenosine to depress evoked potentials in these two strata. It was observed that the receptor differences correlated with differential sensitivities to adenosine modulation of the evoked potentials. These data suggest that receptor density, as shown by binding techniques, may provide not only a qualitative but also a quantitative map of the sites of adenosine action.     

Parallel investigations of the effects of adenosine on evoked potentials and cyclic AMP accumulation in hippocampus slices of the rat.

In slices of rat hippocampus, adenosine and its receptor agonist, 2-chloro-adenosine, were both found to (a) enhance the intracellular accumulation of cyclic adenosine monophosphate (cAMP) and (b) depress neuronal evoked responses to electrical stimulation. The differences in the dose/effect curves for the biochemical and electrophysiological changes cast doubt on a causal relationship between the two effects.     

Early detection of metastasis by alterations in the cellular immune system in the murine liver and blood

We investigated the reaction of the cellular immune system of liver and blood in the C57BL/6 mouse to a metastasizing Lewis lung carcinoma. The cellular immune system of the liver consists of mature and immature macrophages, B-cells, T-cells including their subpopulations, and natural killer cells, and their percentage frequencies differ significantly from those in the corresponding mononuclear blood cell (MBC) compartment. This suggests that the hepatic immune cells represent a system with autonomous function showing a typical homing of its members. Imminent metastasis to the liver is signalled by impressive alterations in the percentage frequencies of nonparenchymal liver cells (NPLC). There are a dramatic loss of mature macrophages, an increase in immature macrophages, a reduction of T-helper cells leading to a low CD4/CD8 ratio, and an increase in natural killer cells. In the blood, the corresponding precursor cells show comparable changes with a delay of at least 2 days. Early metastasis is accompanied by a significant increase in mononuclear NPLC producing tumour necrosis factor . The alterations in percentage frequencies of the NPLC during tumour metastasis differ markedly from the changes in these cells in the liver during endotoxinaemia.     

The control of Staphylococcus epidermidis biofilm formation and in vivo infection rates by covalently bound furanones

In order to overcome the continuing infection rate associated with biomaterials, the use of covalently bound furanones as an antibiofilm coating for biomaterials has been investigated. Furanones have previously been shown to inhibit growth of Gram-positive and Gram-negative bacteria. The aim of these studies were to covalently bind furanones to polymers and to test their efficacy for inhibiting biofilm formation of Staphylococcus epidermidis and in vivo infection rate. Two methods of covalent attachment of furanones were used. The first, a co-polymerisation with a styrene polymer, and second, a plasma-1-ethyl-3-(dimethylaminopropyl) carbodiimide (EDC) reaction to produce furanone-coated catheters. Biofilm formation by S. epidermidis in vitro was inhibited by 89% for polystryene-furanone disks and by 78% by furanone-coated catheters (p<0.01). In an in vivo sheep model we found furanones were effective at controlling infection for up to 65 days. Furanones have potential to be used as a coating for biomaterials to control infection caused by S. epidermidis.     

Propentofylline (HWA 285) protects hippocampal neurons of Mongolian gerbils against ischemic damage in the presence of an adenosine antagonist

The effect of the xanthine derivatives theophylline and propentofylline (HWA 285) on postischemic selective nerve cell damage was studied in the hippocampus of the Mongolian gerbil and assessed by measuring the decrease of Nissl staining in the CA1 area. Theophylline administered 15 min prior to a 2-min period of bilateral carotid occlusion led within 4 days to a marked damage of CA1 neurons which was not seen in untreated animals. Prolongation of the ischemic period to 5 min led to the same degree of damage in theophylline-treated and untreated animals revealing that the protective power of endogenous adenosine is limited. In contrast to theophylline, treatment with propentofylline (10 mg/kg, i.p.) antagonized cell death; such a protection by propentofylline was also achieved after 5 min ischemia in animals treated with theophylline. This indicates that propentofylline does not exert its protective effect via adenosine-mediated mechanisms.     

Pharmacological blockade of Cl- pumps or Cl- channels reduces the adenosine-mediated depression of stimulus train-evoked Ca2+ fluxes in rat hippocampal slices.

Stimulus train-evoked decreases of the extracellular Ca2+ concentration (delta Ca) were measured with ion-sensitive electrodes in the CA1 area of rat hippocampal slices. The adenosine receptor antagonist, theophylline, led to a marked increase of delta Ca in the synaptic and in the soma layer reflecting an increased activation and enhanced frequency potentiation of pyramidal neurons in the absence of endogenous adenosine action. The theophylline effect was significantly reduced in the presence of the C1 channel blocker, 4,4'-diisothiocyano-2,2'-stilbenedisulfonate (DIDS) or of the Cl- pump blocker, furosemide. The data indicate that the adenosine-mediated modulation of the repetitive input strength is related to the function of Cl- ions.     

Neuropsychological Deficit and Academic Performance in Children and Adolescents Following Traumatic Brain Injury

Evaluated the utility of neuropsychological testing in predictingacademic outcome in children 1 year following traumatic braininjury (TBI). Fifty-one schoolage children who were admittedto hospital after TBI were assessed with a battery of neuropsychologicalmeasures at 3 months postinjury. Academic achievement was assessedat 3 and 12 months postinjury. The neuropsychological batteryincluded intelligence testing and measures of memory, learning,and speed of information processing. Academic outcome was assessedin terms of post-TBI changes in reading, spelling, and arithmetic;changes in teacher ratings of school performance; and changein school placement. According to logistic regression analysis,change in placement from regular to special education at 1-yearpost-TBI was predicted by injury severity and by neuropsychologicalperformance at 3 months post-TBI. Findings suggest that neuropsychologicaltesting is useful in identifying children with special educationalneeds subsequent to TBI.