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Biomedical subjects

T H Schiebler

Publications and source records attributed to T H Schiebler.

At least 37 records · Page 2Linked to original sources
PubMed1978

[Uptake of peroxidase by activated nerve cells of the hypothalamus (author's transl)].

After thirst or adrenalectomy followed by dehydration electron microscopy reveals an activation and an increased uptake of peroxidase in the nerve cells of the supraoptic, paraventricular, ventromedial and praemamillar nuclei. The amount of peroxidase which is taken up runs parallel with the activation of the corresponding nerve cells. After rehydratation the activity of the nerve cells and the uptake of peroxidase decrease. The incorporation of the enzyme by the nerve cells differs depending on the region investigated: After thirst peroxidase is taken up especially by the nerve cells of the supraoptic and paraventricular nuclei. After adrenalectomy, however, this is true for the ventromedial and praemamillar nucleus. In the magnocellular nuclei peroxidase is preferentially incorporated by the perikarya, whereas in the parvocellular nuclei the uptake of the enzyme predominates in the dendrites. Within the nerve cells peroxidase is only seen in heterophagic bodies. The ependyma above the paraventricular nucleus takes up peroxidase in low amounts via the cell membrane which borders the III. ventricle; high amounts are incorporated by the lateral and basal plasmalemma.

Animals↗
PubMed1978

[Glia of median eminence. Electron microscopic studies of normal, adrenalectomized and castrated rats ].

The glia is investigated in an oral and middle region of the median eminence (EM). Both zones have in common that they can be subdivided in the ependyma and subependyma (with ependymal cells, tanycytes and some oligodendroglial cells, astrocytes and glia which cannot be further classified), internal zone (with astrocytes, oligodendroglia and microglia) and external zone (with astrocytic tanycytes, microglia and a few astrocytes). Quantitative differences exist between the oral and middle part of the EM since the area which is occupied by the glia decreases per section in the caudal direction. For the first time a new type of glia cells is described which are designated as astrocytic tanycyte; they posses the structural features of tanycytes as well as of astrocytes.--After adrenalectomy and castration the area of the glia is bigger in the external zone than in untreated animals. Under the same conditions the number and size of the lipoprotein granules of the glia increase. A general activation of the glia of the EM occurs which is considered to be a reaction which runs parallel with the stimulation of the neurosecretory systems.

Adrenal Glands↗
PubMed1977

Light and electron microscopic observations of the autonomic innervation of the mouse gallbladder mucosa. A histochemical, cytochemical, and secretory study.

The autonomic innervation of the mouse gallbladder mucosa was studied using histo- and cytochemical methods. In a light microscopic investigation the distribution of acetylcholinesterase (AChE) activity and formaldehyde-induced fluorescence was studied histochemically. Nerve fibres and small varicosities showed concentrations of AChE activity very close to the epithelium in the subepithelial connective tissue. No adrenergic nerves were observed in the mucosa. When using the electron microscope and employing the potassium permanganate fixation/staining technique only one sort of axonal enlargement was encountered, viz. the cholinergic type. These varicosities contained numerous agranular vesicles (500-600 A in diameter). No varicosities of the adrenergic (dense-cored vesicles) type were observed. Signs of increased secretory activity in the epithelium were observed in the first few minutes after cholinergic stimulation. After repeated in vivo stimulation, there was an almost total depletion of glycoprotein granules, best seen when using the cytochemical PA-CrA-silver technique. The findings suggest that the subepithelial connective tissue and the epithelium of the mouse gallbladder mucosa have a cholinergic innervation.

Acetylcholinesterase↗
PubMed1975

[The development of the guinea pig gallbladder epithelial cells. I. Light microscopical and carbohydrate-histochemical investigations (author's transl)].

The development of the guinea pig gallbladder epithelium was studied from the 19th day of intrauterine life to the 31st postnatal day by means of histological and histochemical staining reactions. At first, the epithelium is a columnar pseudostratified one. Its transformation into a simple columnar eptihelium is terminated by the 31st day of the intrauterine life. Then the epithelial cells become more columnar and their nuclei acquire a basal position. Somewhat later the epithelium invaginates the underlying mesenchyme. Up to the 57th day the epithelium contains much glycogen. Neutral and carboxylated mucosubstances are demonstrable after the 30th day. From the 48th day onwards sulphated mucosubstances can be visualized in some cells in the depth of the invaginations and from the 51st day in the epithelial cells of the gallbladder. "Light" mucoid cells appear first in the epithelium of day 58. After the 6th postnatal day the "light" cells are rarely seen in the invaginations. The development of the gallbladder epithelium is completed about the 10th postnatal day. The epithelial mucosubstances of the gallbladder of the adult animal could be classified as GC- mucins and S-mucinsA, 1.0 MgCl2.

Animals↗
PubMed1975

[The development of the guinea pig gallbladder epithelial cells. II. Electron microscopical and enzymhistochemical investigations (author's transl)].

The development of the guinea pig gallbladder epithelium follows a distinct time schedule. During the first phase (up to 30th day of intrauterine life) the epithelial cells increase in number. They remain small and undifferentiated. In the second phase, from the 30th to the 44th day, cytodifferentiation is a dominating feature. The epithelial cells increase in height, the nuclei become more basal, the cells acquire their final zonal structure and the cell organelles exhibit their characteeristic appearance. Weak enzyme activities can be observed. In the third phase, from the 45th day until birth, there is functional differentiation and the adult pattern of enzyme distribution is established. Glycogen appears first on day 29, increases in amount and then disappears by day 57. There is a marked development of the Golgi apparatus associated with increased synthesis of secretory material. Between the 59th embryonic day and the 6th day of life mucoid cells with different functional states appear in the gallbladder epithelium. Later on these cells can be visualized only in the depths of the invaginations. After birth the epithelial cells become more columnar and by 10 days after birth the adult appearance of the epithelium is fully established.

Animals↗
PubMed1975

Relations between development of the capillary wall and myoarchitecture of the rat heart.

The type of the blood supply to the myocardium appears to be closely related to its structural arrangement. The heart of adult poikilotherm animals is either entirely spongious, supplied from the ventricular cavity or its spongious musculature is covered by an outer compact layer with vascular supply. The size of the compact layer increases with increasing heart weight. The changes in the heart size during the ontogenetic development of honoiotherms are accompanied by the gradual transformation of the vascularless spongious musculature into a compact myocardium supplied thrugh coronary vessels. Up to the development of coronary arteries (in the rat up to the 17th day of embryonic life - ed) the myocardium is entirely spongious and supplied from mentricular cavity. Two types of primitive vascular bed are characteristic for this period: a) intertrabecular spaces, which penetrate deep into the ventricular wall as direct continuation of the endocardium, and b) intramyocardial clefts without endothelial lining. During further development of the terminal mascular bed, the outgrowth of endothelial cells into the myocardial clefts is important. The first capillaries with closed endothelial wall can be observed on the 18th ed. At this time various developmental stages o the terminal blood bed can be observed simultaneously. Within the following period (20-21 ed) the thick capillary walls become narrow and pericytes occur. The process of differentiation spreads in both ventricles and in septum from the base to the cardiac apex and is practically finished by the 14th day of postnatal life. The longitudinal orientations of myofibres starts between the 20th and 22nd ed. The final arrangement of muscle cells and capillaries into three layers (outer and inner longitudinal, central circular) is terminated during the second postnatal week.

Animals↗