Perithelial Cells Research Articles

Chronobiological studies on the blood-brain barrier

Horseradish peroxidase (HRP) is a useful tracer for a study of the transportation of exogenous materials across vascular walls. After i.v. administration of HRP, reaction products of HRP can be recognized in the granular perithelial cells of small cerebral blood vessels at particular times of day. It suggests that there is a time-dependent fluctuation in the permeability of small cerebral blood vessels.

Influences of age and vasopressin on the uptake capacity of fluorescent granular perithelial cells (FGP) of small cerebral vessels of the rat.

Fluorescent granular perithelial cells (FGP) were found in the perivascular space around fine cerebral blood vessels. Their profiles and intracellular inclusions varied with the age of the animals. The FGP are able to take up exogenous substances administered intraventricularly. With light and electron microscopy, the relation between the uptake capacity of FGP and the aging of animals was studied using horseradish peroxidase (HRP). The effects of vasopressin on the uptake of HRP also were examined. The results can be summarized as follows: 1) The uptake capacity of FGP diminished with aging, that is, the reaction product of administered HRP was found abundantly in FGP in young rats, while it was sparse in the FGP of old rats and 2) vasopressin increased the incorporation of HRP into the FGP of both young and old rats. The possible role of vasopressin in modulating the uptake capacity of FGP is considered, and the difference between FGP and other perivascular cells are discussed.

Uptake of exogenous substances and marked infoldings of the fluorescent granular pericyte in cerebral fine vessels.

Exogenous substances such as trypan blue and horseradish peroxidase administered intraventricularly are taken up by granular pericytes in cerebral fine vessels. These cells are provided with elongated and complicated infoldings. Pinocytotic vesicles occur often along the infoldings, and ends of infoldings are swollen and assume vesicular shapes. The specific morphology of the granular perithelial cells is considered to favor a removal of metabolic wates in cerebral tissue.

Involvement of Peripheral Nerve and Muscle in Fabry's Disease

Light microscopic and ultrastructural studies of biopsy specimens from the sural nerve and the gastrocnemius muscle in a patient with Fabry's disease showed accumulation of lipids in endothelial and perithelial cells of the vessel walls. In addition, the peripheral nerve exhibited deposition of lipids in the perineurial cells, occasionally in unmyelinated and myelinated axons, and infrequently in Schwann cell cytoplasm. In the muscle biopsy specimen, stored lipid was found in the sarcoplasm. Quantitative histologic studies showed loss of large unmyelinated and thin myelinated nerve fibers. Excruciating pain and loss of sweating, characteristic of this disorder, may result from loss of these fiber categories. The peripheral neuropathy is probably secondary to perikaryal deposition of lipid as described previously in the literature.

Electron Microscopy of Urinary Sediment in Fabry's Disease

<h3>To the Editor.—</h3> Authors of the CLINICAL NOTE "Urinary Ultrastructural Findings in Fabry Disease" (237:1121, 1977), Sheila M. Katz, MD, and Patricia J. Lyons, MD, concluded that electron microscopic examination of the urine may be useful in the diagnosis of Fabry's disease with renal involvement. In 1970 Duncan¹reported three cases of Fabry's disease studied by electron microscopy. In two of his cases urinary sediment showed the presence of laminated, round osmiophilic bodies, similar to those found in renal foam cells. Duncan suggested that electron microscopic studies of urine for osmiophilic bodies may be of use as an indication of glomerular recovery in a follow-up of treated patients. Recently electron microscopic studies of gingival mucosa have also been used in the diagnosis of Fabry's disease. Osmiophilic bodies were found in endothelial, perithelial, fibroblastic, phagocytic, and epithelial cells of gingival mucosa of affected persons.² Early diagnosis of this interesting

Electron microscopy of urinary sediment in Fabry's disease

<h3>To the Editor.—</h3> Authors of the CLINICAL NOTE "Urinary Ultrastructural Findings in Fabry Disease" (237:1121, 1977), Sheila M. Katz, MD, and Patricia J. Lyons, MD, concluded that electron microscopic examination of the urine may be useful in the diagnosis of Fabry's disease with renal involvement. In 1970 Duncan¹reported three cases of Fabry's disease studied by electron microscopy. In two of his cases urinary sediment showed the presence of laminated, round osmiophilic bodies, similar to those found in renal foam cells. Duncan suggested that electron microscopic studies of urine for osmiophilic bodies may be of use as an indication of glomerular recovery in a follow-up of treated patients. Recently electron microscopic studies of gingival mucosa have also been used in the diagnosis of Fabry's disease. Osmiophilic bodies were found in endothelial, perithelial, fibroblastic, phagocytic, and epithelial cells of gingival mucosa of affected persons.² Early diagnosis of this interesting

The ultrastructure of Sturge-Weber disease.

Five infantile and one adult case of Sturge-Weber disease were studied pathologically. The calcification occurring under the leptomeningeal angiomatosis increased with advancing age. Light and electron microscopy of two cases showed the smallest, and therefore possibly the earliest, calcifications occurred in perithelial cells. It is hypothesized the cause of calcification is anoxic injury to endothelial, perithelial and possibly glial mitochondria due to stasis and abnormal vessel permeability in the cerebral vessels composing the Sturge-Weber angioma.

The role of acid esterase in the pathogenesis of xanthoma. A histochemical study in rabbits.

Previous studies of our group indicated that two types of cells are involved in the pathogenesis of atheroma. The one type, myocytes, are poor in acid esterase activity, store lipid droplets which they cannot hydrolyze and are transformed into foam cells. The other type, macrophages, are rich in this enzyme activity, can and do hydrolyze the esters with possible healing by fibrosis. In the present study the importance of acid esterase activity in experimental xanthoma in hyperlipidemic rabbits was studied. Perithelial cells of small blood vessels were found to be poor in acid esterase activity and to contain bulky lipid masses. With time, increasing numbers of cells with high enzyme activity were found mainly at a distance from the vessels. These cells, which mostly contained finely emulsified lipids are believed to be macrophages. Thus, in both atheroma and xanthoma, vessel wall cells take a "passive" part in formation of the lesion, while blood borne cells play a role in disposing of the lipid with eventual possibility of healing.

The histogenesis of Kaposi sarcoma: a histochemical and electronmicroscopical study (author's transl)

1. Histologically, Morbus Kaposi is primarily characterized by a proliferation of streams composed of spindle-shaped cells, by vascular slits lined by cells, and by a minor cellular inflammatory reaction. 2. The cells lining the vascular slits resemble endothelial cells and exhibit strong alkaline phosphatase activity and a clear leucinaminopeptidase activity. They contain Weibel-Palade bodies. 3. The ultrastructural analysis of the tumor cells shows a proliferative formation resembling capillary sprouts with and without lumina. The lumina are composed primarily of poorly differentiated endothelial cells. A second typical cellular component are fibroblast-like tumor cells possibly derived from perithelial cells. 4. Indicative of M.K. are also extravasation and phagocytosis of erythrocytes with intracytoplasmic decomposition, and storage of myelinlike structures somewhat resembling Schwannian-cells. 5. M.K. is characterized by a multifocal neoplasia of capillary like structures and by a progressive sarcomatous development.

Alterations in the hippocampus of aged mice.

The hippocampus of C57B1/6 mice was examined histologically and electron microscopically. Male and female mice at 3 and 8 months of age and female mice at 16 months of age were studied. PAS positive foci, containing particles 1-2 mu in diameter, were observed in the hippocampal region of 8 and 16 month old mice. These particles were diastase sensitive. Electron microscopically, in similar mice, a vacuolating change was observed in the cytoplasm of perithelial cells (pericytes) in the same area.

Fabry's disease on the mechanism of the peripheral nerve involvement.

A sural nerve biopsy of a patient with Fabry's disease showed depletion of larger myelinated fibres, but smaller myelinated and unmyelinated fibres were intact. Epineurial and to a lesser degree endoneurial vessels revealed abundant lamellar inclusions in the endothelial and perithelial cells. Larger myelinated nerve fibres contained glycogen granules in the vacuoles caused by splitting of the adaxonal membranes. A skin biopsy revealed abundant inclusions in the secretory cells and myoepithelial cells of the sweat glands. The lumen of the gland was packed with inclusions like those in the vessel walls. The pain and anhydrosis might be caused by accumulation of glycolipid in the vasa nervorum and sweat glands and not by autonomic nerve involvement.

Enzyme histochemical and ultrastructural alterations in the brains of Friesian calves with GM1 gangliosidosis.

Histoenzymic and ultrastructural alterations in the brains of seven calves with GM1 gangliosidosis are described. A decreased oxidative enzyme activity in neurons was accompanied by an increase in acid phosphatase activity. Membranous cytoplasmic bodies were present in neurons and glia. The periodicity of the membranes was about 5.5 to 6.0 nm. Electron-dense, membrane-bound inclusions were present in perithelial cells. The lesions were compared with those of gangliosidoses in other species.

The central nervous system in Fabry's disease. An ultrastructural study.

An ultrastructural study of the central nervous system (CNS) in a case of Fabry's disease revealed intraneuronal inclusions of four types in the amygdala. These included zebra bodies and granulomembranous bodies similar to those seen in Hurler's syndrome, an inclusion made of concretions of delicate membranes and amorphous material, and lipofuscin bodies. Perithelial cells throughout the nervous system contained zebra bodies and granulomem-branous bodies, as well as inclusions resembling zebra bodies on end. Endothelial cells contained myelin ovoids. The inclusions seen ultrastructurally in the CNS differed from those seen in other regions of the body.

Perivascular accumulation of lipids in the infant human brain

The accumulation of sudanophilic material in and around small telencephalic vessels was studied in 215 randomly collected brains of infants and children up to 8 years in relation to age and the primary lethal disease process. Before the fourth postnatal week lipid deposits occur in the premyelination glia and in endothelial and perithelial cells. After this age, lipid droplets and lipid-laden macrophages are present in variable amounts around small veins and arterioles, predominantly in the subcortical white matter and deep cerebral cortex and, occasionally, in the internal capsule and around subependymal veins. The highest amounts are present between the age of 3 and 6 months during the gradual disappearance of the lipid-laden premyelination glia, and then constantly decrease up to the age of 3 years. The occurrence and intensity of perivascular lipid deposits are apparently independent of cerebral oedema and without relation to any primary lethal disease. These lipid aggregates contain unsaturated triglycerides, cholesterol esters and phospholipids, whereas there is no evidence of sulphatides and cerebrosides, They are considered to be physiological findings and are attributed to the export of residual and excess lipid material not used in the formation of myelin.

Evidence for the chylomicron origin of lipids accumulating in diabetic eruptive xanthomas: a correlative lipid biochemical, histochemical, and electron microscopic study.

Plasma lipoprotein alterations in nine insulin-dependent diabetics with hyperlipemia have been related to the lipid accumulating in eruptive xanthomas evolving in these patients. Histochemical and electron microscopic examination of xanthomas have been correlated with the lipid analyses in order to obtain additional evidence regarding the lipoprotein origin of lipids accumulating in the lesions. Both analytical and morphologic evidence suggested that circulating chylomicrons significantly contribute to the xanthoma lipids. All the patients had large quantities of circulating triglyceriderich chylomicrons which carried approximately 70% of the triglyceride found in the plasma. The fatty acid pattern of chylomicron and xanthoma triglycerides were similar. Triglyceride constituted the major lipid found in the xanthomas when they were sampled during their eruption. These findings, take in conjunction with histochemical and electron microscopic evidence of chylomicron particles in the dermal capillary walls, support the theory that blood lipoproteins, and particularly chylomicrons, permeated the vascular walls and the triglycerides carried by these lipoproteins apparently accumulated in tissue macrophages and perithelial cells which evolved into foam cells. Initiation of appropriate therapy resulted in clearance of the chylomicronemia and a concomitant resolution of the xanthomas as reflected by a decrease in total xanthoma lipid. Sequential studies of resolving xanthomas in five patients revealed that xanthoma triglyceride was mobilized more rapidly than cholesterol, resulting in a redistribution of the xanthoma lipids, so that the resolving lesions were cholesterol rich. Consistent with this change in lipid composition, correlative electron microscopy revealed loss of amorphous material from many of the foam cell vacuoles.

Fine structural localization of cholinesterase activity in the rat brain stem

Thiolacetic acid is hydrolyzed in the rat medulla oblongata by four separate enzyme systems, i.e., by specific cholinesterase, nonspecific cholinesterase, nonspecific esterase, and possibly cathepsin C. The activity of these enzymes can be distinguished by inhibition studies. Specific cholinesterase activity is largely confined to neurons, where it is chiefly associated with portions of the endoplasmic reticulum and with synapses. Only some synapses showed activity and this was confined to pre- and postsynaptic membranes and to some synaptic vesicles. Nonspecific cholinesterase activity is prominently found in neuroglia cells, particularly fibrous astrocytes, and perithelial cells. Within these cells the reaction product was particularly evident on the nuclear membrane and in the Golgi complex. Perithelial cells contained much enzyme activity, which was primarily associated with the granules of the endoplasmic reticulum. Dense bodies found in neurons, neuroglia cells and perithelial cells contain an organophosphate-resistant esterase, or cathepsin C, which hydrolyzes thiolacetic acid. Some of these enzymatically active dense bodies appeared to arise from the Golgi complex. Glutaraldehyde is advocated as a general fixative for the central nervous system; however, caution is advised concerning its use to demonstrate this type of enzyme activity in the brain.

NONCHROMAFFIN PARAGANGLIOMA (GLOMUS JUGULARE TUMOR) OF MIDDLE EAR

MORE THAN 100 years ago Valentin 1 described swelling surrounding the ramus tympanicus of the glossopharyngeal nerve in its course through the tympanic canal which he designated the gangliolus In 1878 Krause 2 wrote concerning this swelling around the ramus tympanicus, describing vascular tissue consisting of a foundation of connective tissue with elastic fibers; it contains arteries, veins and net-like capillaries. The arteries are branches of the ramulus tympanicus out of the A. pharyngea adscendens, which is 0.12 thick and accompanies the N. tympanicus. The former vascular tissue is characterized by larger or smaller number of three-sided pyramid-shaped or star-shaped perithelial cells of 0.007-0.015 in diameter, the nuclei of which are about 0.004 mm. Also, at times these cells can pile up around the twisted vessels in such way that utricular formations suggest the structure of the G. intercarotica. He suggested the name