Cleft-like Spaces Research Articles

The operative treatment of scapulothoracic bursitis in professional pitchers.

Four professional pitchers with resistant scapulothoracic bursitis who have required surgical excision of the thickened bursa are reported. The average time duration of symptoms prior to surgery was 18.8 months. Conservative therapy consisting of rest, shoulder exercises, antiinflammatory medications, and cortisone injections failed to resolve the bursitis, and each pitcher was unable to compete secondary to pain. The incision was posterior, just distal to the tip of the scapula. The specimens contained cleft-like spaces lined by synovial tissue consistent with a bursa. All four pitchers returned to professional baseball the year following surgical excision of the bursa. We recommend early, aggressive, conservative therapy for scapulothoracic bursitis in the throwing athlete. Pitchers with a thickened, resistant scapulothoracic bursitis should have the bursa surgically excised.

Ultrastructure of epithelial thymic cysts of the chicks.

The medulla of the chick thymus contains variable numbers of intercellular and intracellular cysts. The epithelium varies from squamous to columnar or stratified and contains cystic, endocrine-like, and lymphoid cells. The lumen-lining cystic cells contains microvilli, moderately developed rough- and smooth-surfaced endoplasmic reticulum, and Golgi complex. Mitochondria, free ribosomes, and varying number of microfilaments are observed. Endocrine-like cells are separated from the lumen by the cystic cells, which in places are extremely attenuated. The cytoplasm is characterized by the presence of membrane-limited secretory granules. Cleft-like spaces, partially lined by microvilli, are also encountered. Numerous vesicles, some in tight association with the core rootlets, are evident. Cystic cells with single or multiple cysts, lined with microvilli, are also observed. The lumina of these cystic elements contain flocculent or dense granular material, amorphous masses, cellular elements, or debris. Morphological evidence suggests synthetic and secretory activities of the cystic cells in the young chicks.

Neurobiological studies of experimental diphenylhydantoin intoxication--III. Electron microscopic studies on development and disintegration mechanism of altered axon terminals and synaptic endings in rat cerebellum with chronic diphenylhydantoin intoxication.

The processes of development and disintegration of axonal spheroids were electron microscopically studied in the rat cerebellum with chronic diphenylhydantoin intoxication. According to the severity and character of membrane accumulation, the whole course ranging from development to disintegration of altered axon terminals and synaptic endings in the DPH-intoxicated rat cerebellum was classified into the following four stages--initial, moderate, advanced and terminal. The initial stage was characterized by the appearance of a small number of interconnected tubules 150 to 350 A in diameter in non-enlarged axon terminals and synaptic endings. Usually these tubular structures tended to congregate in a certain part of axoplasm so that there were no intimate relationships between them and ordinary cell organelles. The moderate stage was characterized by an increased number of interconnected tubules in slightly or moderately swollen axon terminals and synaptic endings. The advanced stage was characterized by an extraordinary number of interconnected tubules in extremely highly swollen axon terminals and synaptic endings. Membranous scrolls and/or membranous strands separated by a cleft-like space were also found in an association with interconnected tubules so that the morphological organization of spheroids in the rat cerebellum with chronic DPH intoxication was very analogous to those of infantile neuroaxonal dystrophy. The terminal stage was characterized by the following three axonal events, i.e., rarefaction and coagulation necroses, and phagocytosis of spheroids by glial elements, presumably astrocytic in origin. The formation and fate of such axonal spheroids have not as yet been shown and discussed by electron microscopists. Thus the present paper was the first to reveal the electron microscopic observations suggestive of the details of development and disintegration mechanisms of spheroids by means of animal experimentations.

Neurobiological Studies of Experimental Diphenylhydantoin Intoxication

The effect of chronic administration of diphenylhydantoin on the fine structures of the rat cerebellum was ultrastructurally investigated. Materials from nine control rats and 16 experimental rats to which 200 to 300 mg/kg b.wt. of diphenylhydantoin was administered orally for 12 months were studied with the light and electron microscopes. The most striking changes were observed in the presynaptic boutons located predominantly in the molecular layer and the neuropil of deep cerebellar nuclei and sometimes in the granule cell layer. The changes consisted of the proliferation of either interconnected tubules 150 to 350 A in diameter associated with membranous scrolls and/or membranous strands separated by a cleft-like space, or parallel tubules about 600 A in diameter with a honeycomb-like architecture in the cross section, and hypertrophy of the boutons. Other alterations were a generalized increase in the density of the axoplasmic matrix, the accumulation of mitochondria, vesicular structures and dense bodies, an increased number of neurofilaments and a decreased number of synaptic vesicles. The axon displayed morphological abnormalities similar to those found in the terminal boutons. Along with the synaptic and axonic changes mentioned above, the perikaryal alterations in the Purkinje cell and in granule cell layers and deep cerebellar nuclei were also found, but they were generally not so prominent so that they were considered to reflect a non-specific reaction to synapto-axonic changes rather than a primary degenerative change. However, in contrast to the neuronal changes, no indication of damage of the glial elements was found, nor were the vascular changes.

Morphology and distribution of cytoplasmic inclusions in adrenoleukodystrophy

We report some additional observations on the pathognomonic cytoplasmic inclusions in a typical case of adrenoleukodystrophy (ALD). Study of the linear inclusions by means of tilt-stage electron microscopy indicated that they represent trilaminar sheet-like structures distinct from materials seen in various other storage disorders. This study emphasizes that the inclusions in the adrenal and testicular parenchymal cells morphologically differ from those in the brain macrophages. In the latter they occur as membrane-bound discrete structures while in the parenchymal cells they are always seen lying free in the cytoplasm and associated with cleft-like spaces. This morphologic variation of the inclusions is noteworthy and probably reflects a biochemical difference in the storage materials in these two most severely affected organs. In addition, this study demonstrates the presence of linear inclusions within macrophages in otherwise normal-appearing liver, spleen, thymus and also in the renal tubular cells. These findings suggest that the abnormal materials containing very long chain fatty acids enter the blood stream and become sequestered in the reticuloendothelial system and possibly are also excreted in the urine. Detection of these abnormal fatty acids in blood and urine may simplify diagnosis of ALD.

Ultrastructural aspects of normolipidemic xanthomatosis.

Electron microscopic aspects in ten cases of normolipidemic cutaneous xanthomatosis have been investigated. Two additional types IV and V hyperlipoproteinaemic xanthomatosis have also been included. Ultrastructural findings in all cases were similar. Abundant histiocytic cells with numerous intracytoplasmic lipid vacuoles, lysosomes, and myelin-figures, were the striking features. Moreover, in older lesions microfilaments and lipid vacuoles were found in some fibroblastic cells, as well as long space collagen around them. In some specimens we observed: giant multinucleated histiocytic cells, crystalline cleft-like spaces in histiocytes and some mastocytes with lipidic crystals in the extracellular space, as well as lipid vacuoles in Schwann cells, endothelial cells and pericytes. Rod-shaped tubulated bodies were found in some endothelial cells, with multiple basal vascular laminae. In xantelasma palpebrarum and in disseminate plane xanthoma the histiocytary foamy cells adopted a perivascular arrangement, as in hyperlipoproteinemic xanthomatosis. We concluded that ultrastructural aspects of different xanthomatosis are fairly similar as a consequence of the large amount of intracytoplasmic lipids accumulated in xanthomatosus cells. In xanthelasma palpebrarum and in disseminated plane xanthoma this cell phase is reached by similar pathways to those for hyperlipoproteinemic xanthomatosis, whilst in xanthoma disseminatum and juvenile xanthogranuloma the pathways seem to be different. A classification of normolipidemic xanthomatosis is also provided.

The development and structure of Hassall's corpuscles in the guinea pig. A light and electron microscopic study.

The development and structure of Hassall's corpuscles was studied with the light and electron microscopes in 57 guinea pig foetuses, ranging in age from 30 to 65 days gestation. The first evidence of Hassall's corpuscles was seen with the electron microscope between 33–35 days gestation, but the corpuscles showed their main development between 35–46 days gestation. By the end of this period the corpuscles were composed of islands of cells closely resembling keratinized stratified squamous epithelium. Between 46 and 65 days gestation, some corpuscles became infiltrated with polymorphonuclear leucocytes and developed cleft-like spaces around their periphery. These changes were interpreted as evidence of degeneration. No evidence was seen to suggest any specific function for the corpuscles and it is suggested that they develop as the result of a species-dependent manifestation of the potential for differentiation of some thymic medullary epithelial cells.