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  • Erik Dahl
  • 1970
The post-natal evolution of thecal gland in the domestic fowl has been explored, and a hypothesis for this development is proposed. It is suggested that the surface epithelium of the ovary forms crypts and submicroscopic clefts (ingrowing cords) which contribute with epithelial elements required for the regeneration of some of the ovarian elements,(More)
  • Erik Dahl
  • 1973
Intracerebral vessels of the parietal lobe of the rhesus monkey have been examined by electron microscopy with special reference to the relationship between the leptomeninges and the cerebral cortex. A “perivascular reticular sheath”, in apparent communication with the subarachnoid space surrounds intracerebral arterioles. Myo-endothelial junctions occur in(More)
  • Erik Dahl
  • 1973
The fine structure of the pancreatic nerves of the domestic fowl has been studied. Naked axon beadings were found in membranous contact with endocrine as well as exocrine cells. From an anatomical point of view it seems reasonable to suggest that the endocrine glands might be subjected to some influence of the autonomic nervous system.
On the basis of ontogeny and adult morphology, an interpretation of the arrangement of optic neuropiles and fibre connexions of the Crustacean compound eye is presented. In the embryo of phyllopods and decapods, the ommatidia, the lamina ganglionaris, and the medulla externa are developed synchronously from a common medial proliferation zone. As this zone(More)
The localization of biogenic monoamines in ganglionic tissues from Anodonta piscinalis, Helix pomatia, and Buccinum undatum has been studied by means of the histochemical fluorescence method of Falck and Hillarp. In cerebral, visceral, and pedal ganglia (besides nonfluorescent nerve cells) neurons emitting a green or yellow fluorescence were found. No other(More)
Why are scientific collaborations so difficult to sustain? Inspired by the vision of Wil-liam Wulf (1989, 1993) and others, researchers over the last twenty-five years have made a number of large-scale attempts to build computer-supported scientific collaboration environments, often called collaboratories (National Research Council 1993). Yet only a few of(More)
  • Nils Magnus Ulvik, Erik Dahl
  • 1981
Membrane-bounded spherical vesicles found in rat Sertoli cells have been examined quantitatively during the cycle of the seminiferous epithelium. Most of the vesicles were localized to the basal and columnar portions of the Sertoli cell cytoplasm. The thin lateral projections of the Sertoli cells contained very few vesicles. Morphometric analysis of the(More)
BACKGROUND In recent years, convincing evidence has emerged implicating tumor necrosis factor alpha as a causative factor in radiculopathy and discogenic back pain. But although preliminary open-label studies demonstrated promising results for the treatment of low back pain with tumor necrosis factor-alpha inhibitors, early optimism has been tainted by a(More)
BACKGROUND The inflammatory cytokine tumor necrosis factor-alpha has been shown to play a pivotal role in the development and maintenance of a wide variety of neuropathic pain conditions. Not surprisingly, systemic treatment with drugs that block tumor necrosis factor have been demonstrated to alleviate pain and pain-related behaviors in clinical and(More)
  • Erik Dahl
  • 1971
The granulosa cells of the ovarian follicle of the rat and the domestic fowl have been studied with the light and electron microscope. The nuclei of the granulosa cells were irregular with indentations and large in proportion to the cytoplasm of the cell. The mitochondria had a dense, dark matrix with only few cristac. The Golgi apparatus was moderately(More)