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Biomedical subjects

W Roggendorf

Publications and source records attributed to W Roggendorf.

85 records · Page 5Linked to original sources
PubMed1981

Effects of chronic exposure to diluted automotive exhaust gas on the CNS of normotensive and hypertensive rats.

Regarding the potential impact of traffic-born air pollutants on public health, attention during the last years has been increasingly focused on the possible effects in high-risk groups of the population. In order to evaluated this point further, the combined influence of both, chronic arterial hypertension and long-time exhaust gas exposure on the CNS has been studied. Both, normotensive Wistar) and spontaneously hypertensive rats (SHR) of either sex were exposed 5 X 8 hours per week for up to 18 months to atmospheres polluted by the emissions of an idling Otto engine with CO concentrations held constant at about 0,90 and 250 ppm, respectively. Biochemical data, body weight, and blood pressure were checked regularly. Characteristic histomorphological findings in the non-exposed SHR brains were hyalinosis and hyperplasia of intracerebral arterioles and -- in some cases -- small focal hemorrhages and infarcts. In the exposed SHR brains, large infarcts of the hemisphere and in the basal ganglia were found, which possibly corresponds to the increase of the mortality rate in SHR. We assume that the increase hematocrit plays an important role in the disturbance of microcirculation of the CNS.

Air Pollutants↗
PubMed1981

Histological examination of the rat after long-term exposure to subtoxic automotive exhaust gas.

Regarding the potential impact of traffic-born air pollutants on public health, in recent years attention has increasingly been focused on the possible effects on the cardiovascular system. In order to investigate this problem further, the influence of long-term exhaust gas exposure on rats has been studied. One hundred Wistar rats of either sex were exposed 5 X 8 h/week up to 28 months to an atmosphere polluted by the emissions of an idling Otto engine, CO concentrations held constant at 90 ppm. A second group (50 rats) was exposed to 250 ppm for 6 months. Blood parameters and body weight were controlled. Specimens of CNS, heart, vessels, kidney etc. were investigated light microscopically. Focal necroses of the myocardium with inflammatory reactions as well as interstitial fibrosis were found in the heart muscle of the 90 ppm group. In the 250 ppm group endothelial proliferations, edema of the intima and deposits of proteoglycanes in the media were observed. We conclude that subtoxic concentrations of CO which only lead to slight morphologic changes may aggravate preexisting lesions caused by high risk conditions, e.g., hypertension or hypercholesteremia.

Animals↗
PubMed1980

[The differential diagnosis of chronic tympanic effusion (author's transl)].

Three patients are reported in whom sound-conduction deafness was caused by malignant tumors in the tubal-tympanic area of the middle ear. In all patients, physical examination (inclusive of the ear and nasopharynx) had essentially been normal for a long time. In each patient, the tympanogram obtained indicated a tympanic effusion which, however, proved to be therapy-resistant. The first patient was found to have a malignant melanoma of the auditory tube while the second patient had an adenoid cystic carcinoma of the middle ear. The last patient had a primary carcinoma which at first showed only peritubal and submucosal growth.

Adult↗
PubMed1978

Ultrastructure of venules in the cat brain.

Intracerebral venules of the cat were examined to establish criteria for a distinct separation between the venous and arterial system, and to characterize, in greater detail, the mural construction of individual venules. The intracerebral venules compared with those of other organs. Venules do not have a vascular wall composed clearly of endothelium, media, and adventitia, as is characteristic of arteries and arterioles. The venous endothlium has a similar structure to that of capillaries. The periendothelial cells of the venule differ in shape depending on the vascular diameter. The number of periendothelial cell processes in postcapillary venules increases progressively. Segments in which the basal lamina of the endothelium merges with that of the glia cover a smaller portion of the circumference than in venous capillary loops. In collecting venules, the endothelium is almost completely enveloped by periendothelial cells which have a larger number of filaments. There are no typical smooth muscle cells in the intracerebral venules. The perivascular space becomes wider in collecting venules, contains adventitial cells, phagocytes and a great number of collagen fibers.

Animals↗
PubMed1977

Spastic constriction of cerebral vessels after electric convulsive treatment.

The brains of nine cats were subjected to bitemporal electric convulsive treatment. The current (AC, 220 V, 50 Hz, ca. 500 mA, 500 ms) was applied two to five times. Pial vessels were observed through a skull window. Immediately after current application, some pial arteries exhibited segmental spastic constriction which usually did not disappear until the animals were killed. Before sacrificing the animals, 20 min after convulsive treatment they were perfused with a carbon suspension. In some cortical areas blackening was impaired indicating that perfusion was not complete. Electron-microscopic investigation revealed that spasm also occurred in arterioles of the brain parenchyma. Many arterial vessels, some of them possessing only one muscular cell sheat, had collapsed so that the lumen was merely a small cleft. The spasms were irregularly distributed and confined to small segments of the vessel. Small arteriolar vessels were more affected than large pial arteries. Arterial spasms continued for 20 min. In a total of 39 control animals spastic constriction was observed only once; this animal had been subjected to prolonged hypocapnia.

Animals↗
PubMed1977

Ultrastructure of arterioles in the cat brain.

A total of 110 arterioles were examined in the brains of cats; different sites were studied including the cortex, putamen, pons and crus cerebri. No internal elastic laminae were seen in the subendothelial space, although occasional fragments of elastic material were present in the larger arterioles. The media was composed of one, two or three layers of smooth muscle cells which interlocked in such a way that the vessel wall thickness was constant. Numerous tight junctions were seen between adjacent smooth muscle cells and between the endothelium and smooth muscle cells. Apart from the usual cell organelles, the smooth muscle cells of arterioles had numerous dense patches on the cell surface. The structure of the adventitia varied according to the diameter of the vessel and the site in the brain; it contained adventitial cells, bundles of collagen fibres and nerve fibres. Innervation of arterioles was more constant in the brain stem than in the cortex. Metarterioles had less specialised, atypical smooth muscle cells, a discontinuous media and numerous, extensive myoendothelial tight junctions; they were not innervated by nerve fibres. The diameter of metarterioles was less than 10 micronm whereas that of arterioles was 10-45 micronm. The possible functional aspects of arteriolar innervation are discussed.

Animals↗
PubMedDate not supplied

The morphology of spastic intracerebral arterioles.

Pial and parenchymatous vessels of cat cerebral cortex were subjected to electrical stimulation by direct current by the application of a silver gel electrode to the vessel wall. A current of small intensity (5V, 10mA, 2s) was sufficient to produce spastic constriction of the pial arteries. Arterial spasm was always segmental and lasted up to 20 min. Intracerebral vessels were stimulated by applying a DC of 20 to 100 V, 20 to 150 mA for 30 s to the brain. Intracerebral muscular vessels showed varying diameters and spastic segments in frozen sections and by electron microscopy. The lumen of spastic vessels was collapsed. The vessel wall convoluted, indicating that the factors causing spastic constriction are different from those responsible for physiological vessel wall constriction. In many cases the perivascular tissue of moderately constricted or spastic arterial vessels was destroyed while the tissue around capillaries always remained intact. It is suggested that periarterial tissue destruction is the result of the sudden and powerful constriction in muscular arteries.

Animals↗
PubMedDate not supplied

Light microscope and immunohistological investigations on the brain of Borna disease virus-infected rabbits.

We studied the distribution and composition of perivascular cellular infiltrates and the distribution of the virus-specific antigen of Borna disease in the brains of rabbits inoculated either intracerebrally or intraperitoneally with infectious virus suspensions. Using standard histopathological and immunofluorescence techniques, there was, in all animals, a meningeal inflammatory reaction together with perivenous cellular infiltrates which were most numerous in the structures of the limbic system and basal ganglia, but also prominent in the spinal ganglia and area postrema. Studies with fluorescent anti-IgG antibody (direct technique) showed IgG in 20-25% of the cells in any one perivascular cuff, suggesting that most of the infiltrating cells were T-cells and that B-cells were fewer. Studies with virus-specific antibody showed that, in the early stages of the infection, there was evidence of a globular antigen mainly in neurons, while, at later stages, virus antigen was also demonstrated in oligodendrocytes and microgliocytes. The route of inoculation of the virus had no determining effect on the character or distribution of the cellular infiltrates or on the distribution of virus-specific antigen in the nervous system.

Animals↗
PubMedDate not supplied

Interleukin 10 is expressed in human gliomas in vivo and increases glioma cell proliferation and motility in vitro.

Interleukin 10 (IL-10) is a cytokine with a broad spectrum of immunosuppressive activity, but itoffs role in the oncogenesis of solid tumors is still unclear. In previous experiments we have shown that IL-10 specific mRNA is produced within glial tumors in vivo. The aim of the present study was to investigate the expression of the IL-10 protein in vivo and to identify the cells producing IL-10 within the tumor tissue. Expression levels significantly increased with malignancy of the gliomas. 87.5% of grade III and IV, but only 4% of grade II tumors expressed high levels of mRNA. Elevation of IL-10 serum levels was found in 11% of low grade and in 63.6% of high grade glioma patients. In situ hybridization analysis with combined immunohistochemistry revealed that: a) IL-10 is not produced by infiltrating B- or T- lymphocytes, b) both microglia and astroglia contributed to IL-10 expression in malignant gliomas in vivo. These data suggested the functional role of IL-10 in glioma progression. Therefore, the effects of IL-10 on proliferation and migration of glioma cells were determined in vitro. Two human glioma cell lines were grown as monolayer as well as spheroids in the presence of different concentrations of IL-10. IL-10 increased cell proliferation significantly in both culture systems with a dose optimum of 25 ng/ml. Glioma cell motility was enhanced with 25 ng/ml as the optimal dose. Adding the IL-10 specific antibody reversed both effects. We conclude from our data that IL-10 is involved in the progression of glial tumors, especially in the enhancement of tumor cell proliferation and migration which promotes infiltration of the surrounding tissue.

Brain↗