Kjeld Fredens

The Gordon phenomenon induced by the eosinophil cationic protein and eosinophil protein X

Cerebellar Purkinje cell degeneration after intracerebral injection of eosinophil granulocytes or extracts thereof is known as the Gordon phenomenon. The reaction is said to be highly selective. An eosinophil-derived neurotoxin (EDN) has recently been reported to induce the Gordon phenomenon. However, we report here that two eosinophil-derived proteins, eosinophil cationic protein (ECP) and eosinophil protein X (EPX), may induce the Gordon phenomenon after intraventricular injection. The potency of ECP is far greater than that of EPX and the latter is possibly identical to EDN. The Fink-Heimer staining for degenerating nerve fibers and boutons, however, indicated that the selectivity of the Gordon phenomenon is not as specific as was previously thought, since this method revealed degeneration of all brain areas in proximity to the ventricular system.

Effect of diethyldithiocarbamate (DEDTC) on sulphide silver stained boutons reversible blocking of Timm's sulphide silver stain for “heavy” metals in DEDTC treated rats (Light Microscopy)

SummaryAdult albino rats were given a single intraperitoneal injection of diethyidithiocarbamate (DEDTC) in doses from 7 to 1000 mg per kg body weight and sacrificed by vascular perfusion with buffered sodium sulphide 5 min to several days after DEDTC treatment. Sections of the brains were cut on a cryostat and stained with a physical developer (Timms method).Intravital DEDTC treatment prevented subsequent sulphide silver staining of the hippocampal mossy fibre boutons, other synaptic fields within the hippocampal region, the neuropil in the amygdala, and all other parts of the forebrain except the olfactory bulb and the islands of Calleja. This effect was virtually identical to that recently reported for another chelating agent, dithizone.The effect of a single injection is reversible and its magnitude and duration depend upon the dose.It is suggested that DEDTC combines with transition and group IIb metals present in specific synaptic boutons in the forebrain.

Eosinophil activation in ulcerative colitis:studies on mucosal release and localization of eosinophil granule constituents

Activation of eosinophil granulocytes(eosinophils) seems to contribute to the pathophysiologyof several inflammatory conditions. This process wasevaluated in 18 patients with ulcerative colitis and in 18 healthy controls using intraluminalsegmental perfusion of the sigmoid colon and rectum andimmunoanalysis for eosinophil cationic protein (ECP) inthe perfusate. Immunohistochemistry for eosinophils and neutrophils was made in simultaneouslytaken biopsies and in biopsies from surgical specimenstaken from additional 10 patients. The mucosal releaseof ECP was increased severalfold in patients with UC. The bowel biopsies demonstrated a laminapropria infiltrated with eosinophils. The degree ofeosinophil activation/degranulation was related to theintensity of the inflammatory reaction. Activated eosinophils and extracellular deposits of ECPwere, in particular, seen in crypt abscesses and inareas with damaged surface epithelium. Since ECP ishighly cytotoxic, its release at the site ofinflammatory bowel lesions might reflect a potentialpathophysiological mechanism.

In vitro studies of the interaction between heparin and eosinophil cationic protein

Eosmophil cationic protein (ECP) is a protein specific to the granules of human eosinophil granulocytes. ECP is highly cationic and may damage tissue if not inactivated. Heparin is a highly anionic substance present in mast cells and basophil granulocytes. The present in vitro study shows that ECP can inactivate the anticoagulant activity of heparin probably by the formation of a complex between the two molecules. This function may be of importance for the microenvironment of allergic diseases where secretion of heparin may promote penetration of mast cell products through tissues. Also this may constitute one mechanism whereby the cytotosic action of ECP is neutralized.

Relationship of afferent inputs to the lattice of high NADPH-diaphorase activity in the mouse superior colliculus

SummaryIn the intermediate gray layer of the superior colliculus there is a lattice of high NADPH-diaphorase activity which represents the terminal distribution of a number of extrinsic afferent systems. These include inputs from the dorsal cholinergic column and cells in the precommissural nucleus and dorsolateral wedge of the central gray substance. Other afferents that terminate in the intermediate gray layer, such as the input from the nucleus of the brachium of the inferior colliculus (BIN), are almost completely segregated from the above inputs and show very little overlap with the NADPH-diaphorase lattice. It is suggested that the input from the precommissural nucleus and central gray substance may have a role in nociception while the input from BIN may provide an important source of auditory information.

Genetic variation in the histoarchitecture of the hippocampal region of mice.

SummaryTimms sulphide-silver method and the histochemical procedures for the demonstration of AChE, MAO and SDH were applied to the brains of three strains of adult mice of either sex: C57/BL/6J, DBA/2J and NMRI.Differences between strains were found 1) in the sulphide-silver pattern of the molecular layer of area dentata, probably reflecting differences in entorhinal, ipsilateral and/or commissural connections, 2) in the distribution of the mossy fibers, 3) in the AChE-staining of a suprapyramidal zone of regio inferior, probably reflecting differences in septal connections, 4) in the AChE-staining of the induseum griseum.The staining patters for MAO and SDH did not vary, at least not qualitatively, between the strains investigated.Variation in adult age and sex did not influence the results.Since the differences observed seemed to reflect a pattern of genetic differentiation, five more inbred mice (A/J, AKR/A, BALB/c/A, C3H/Tif, St/6Fi) were included to strengthen the hypothesis that different genetic systems are operating at separate septo-temporal levels in the same areas during the development of the hippocampal formation.

The effect of intravital chelation with dimercaprol, calcium disodium edetate, 1-10-phenantroline and 2,2′-dipyridyl on the sulfide silver stainability of the rat brain

SummaryDimercaprol, calcium disodium edetate, 1-10-phenantroline and 2,2′-dipyridyl were injected intraperitoneally in adult albino rats in doses ranging from 10 to 1500 mg per kg body weight. Ten animals were injected intracerebrally. At various survival times (2 minutes to several hours) their effects on the staining pattern of heavy metals as revealed by the sulfide silver method of Timm were determined. EDTA was virtually ineffective while dimercaprol, phenantroline and dipyridyl reduced the staining in many regions of the brain. A noteworthy effect of phenantroline was that it reduced the staining of a cortical area, corresponding remarkably well in extent, shape and location to the neocortical somatosensory area.

Golgi Potassium-dichromate Silver-nitrate Impregnation

SummaryGolgi preparations were made by consecutive treatment of formalin-fixed brain and liver with potassium dichromate and silver nitrate. Impregnated tissue dissected from thin slices of the blocks were studied by X-ray powder diffraction methods, in a diffractometer and a Guinier camera. Such tissue proved to contain crystalline silver chromate, Ag2CrO4, both while still in the silver nitrate solution and after dehydration in ethanol and clearing in xylene and xylene-Dammar resin. No other compounds containing chromium or silver were detectable. Formalin-fixed tissue merely treated with silver nitrate contained silver chloride, but in impregnated tissue the amount was too scarce to be visible. Hence, silver chloride was no integral part of the Golgi precipitate.A number of mostly ethereal oils traditionally used for clearing histological sections, did not cause the appearance of metallic silver in detectable amount in the Golgi preparations. However, after treatment with clove oil and creosote metallic silver was detected in the tissue.

The Effect of Oxine and Alloxan on the Sulfide Silver Stainability of the Rat Brain

SummaryAdult albino rats were injected intraperitoneally with oxine and alloxan in doses ranging from 100 to 400 mg per kg body weight. Two minutes to several hours following injection the animals were killed by vascular perfusion with buffered sodium sulfide and the brains immediately removed and frozen. Cryostat sections were prepared and stained according to Timms procedure. A few animals were injected intracerebrally. In contrast to earlier reports by others it was found, under appropriate conditions, that oxine markedly reduced the staining of most parts of the neuropil of the forebrain while alloxan had no effect on the sulfide silver picture at all.

Eosinophils in human cervical ripening

OBJECTIVE Cervical ripening has many similarities to an inflammatory reaction. Eosinophil granulocytes are involved in several inflammatory responses. The objective was to investigate the presence of eosinophils in human cervix uteri during different conditions. STUDY DESIGN Cervical biopsies were obtained from non-pregnant (n = 6), women in early pregnancy (n = 11) and from three groups of women at term: spontaneous vaginal deliveries (n = 5); vaginal deliveries after pretreatment with Prostaglandin E2 (n = 7); and from women who underwent planned Caesarean section (n = 7). Immunohistochemical staining for eosinophil granulocytes (ECP, EG2) were performed. The biopsies were analysed blinded. RESULTS Eosinophils showing degranulation in the tissue were found in all specimens from vaginal deliveries. No eosinophils, or very few were seen in the biopsies from non-pregnant, early pregnant women or planned caesarean section. Prostaglandin treatment had no effect on the results. CONCLUSION Eosinophils participate in cervical ripening at term in women, and seem to arise mainly after labour.