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Biomedical subjects

I Marx

Publications and source records attributed to I Marx.

At least 19 recordsLinked to original sources
PubMed1991

[The pancreatic toxicity of cyclosporin A. An experimental study in rats].

Animal experiments were conducted to elucidate effects of cyclosporine A (CsA) treatment on pancreas. A daily dose of 15 mg/kg B.W. of cyclosporine A was orally administered to recipient animals (rats), over a period of 28 days. Both endocrinic and exocrinic pancreas tissues were morphometrically investigated, using optical light microscopy and electron microscopy. Increase in the exocrinic pancreas portion in response to cyclosporine A treatment was suggested by these morphometric findings. Disorders in the exocrinic pancreas were additionally revealed by electron microscopy. Some of the mitochondria exhibited degenerative alterations, while decline in matrix density as well as separation or rupture of mitochondrial cristae were recorded from others. The assumption might be derived from these results that even therapeutic CsA doses were capable of inflicting disorders on mitochondrial functionally and thus of generating toxic action.

Administration, Oral↗
PubMed1988

Isolation of a new polysaccharide-digesting bacterium from a salt marsh.

A new marine bacterium that digested a variety of storage and structural polysaccharides, including agar, was isolated. Strain 2-40 is a nonfermentative gram-negative, polarly flagellated rod that sometimes grew as a filamentous helix and secreted a melaninlike pigment. Its characteristics conform to those of no previously described species.

Journal Article↗
PubMed1987

31P-NMR spectroscopy and ultrastructural studies on nephrotoxicity of cyclosporine A.

NMR-spectroscopy and electron microscopy were applied in order to find out whether nephrotoxic effects of cyclosporine A in combination with ischaemia on rat kidney are of significance for the energy metabolism of the organ. CSA was administered in daily doses of 15 mg/kg rat over 20 days. Use was made of the particular advantage of 31P-NMR-spectroscopy to follow up the dynamics of high-energy phosphate concentrations in the same tissue. Ultrastructural changes were observed in the region of the proximal tubule. Some mitochondria showed degenerative changes, others increased density of cristae. The total number of mitochondria was increased. This observation together with the coexistence of vacuolarly degenerated mitochondria and mitochondria with increased activity after CSA treatment is interpreted as expression of a compensatory mechanism that keeps constant the totality of high-energy phosphates despite damage to some mitochondria.

Adenine Nucleotides↗
PubMed1987

[Ultrastructural changes in articular cartilage affected by a non-physiological pH value of the synovial fluid].

The physiological pH-value of the synovial fluid (pH 7.2-7.4) is important for the integrity of normal articular cartilage. After the intraarticular injection of acid (pH 4.0) or alkaline (pH 10.0) isoosmolale buffer solutions into the knee joints of young rabbits ultrastructural changes are seen by the aid of transmission electron microscopy. The number of cell organelles in the chondrocytes (rough endoplasmic reticulum, Golgi-complex, mitochondria) is diminished and the number of intracytoplasmic filaments is increased. The intercellular matrix shows a looseness of the collagen fibre mesh work, swollen and split collagen fibres, the appearance of numerous coarse rounded structures with an electron dense envelop, and a loss of matrix granules. These results are interpreted as regressive changes, and they are discussed in the context of an activation of proteinases.

Animals↗
PubMed1984

Morphometric study on the absolute volume of differentiating hepatocytes in rats.

Quantitative changes in the mean absolute volume of rat hepatocytes during prenatal development were studied by light microscopic stereological methods. Combining these light microscopic measurements with electron microscopic relative volume (volume density) data (Daimon et al. 1982) enabled the evaluation of the mean absolute volumes of cytoplasmic organelles of fetuses and newborns. On the 15th day of gestation the mean absolute volume of hepatocytes was 1,523 +/- 10.7 microns3. After 3 days hepatocytes were enlarged 66.2% (2,531.5 +/- 108.2) and at birth 157.1% (3,915.6 +/- 190.8). The comparison of the absolute volume and the volume density of each cell organelle made possible the interpretation of much functional and morphometric data of the development of hepatocytes.

Animals↗
PubMed1984

Stimulation of wound healing, using brain extract with fibroblast growth factor (FGF) activity. III. Electron microscopy, autoradiography, and ultrastructural autoradiography of granulation tissue.

A bovine brain fraction with FGF activity (fibroblast growth factor) increased the formation of granulation tissue of rats in an experimental wound healing model. It was characterised by intensified formation of new capillaries, stimulation of the synthesis function of fibroblasts and myofibroblasts, and proliferation of freshly developed granulation tissue. The results obtained from light microscopy and autoradiographic electron microscopy with 3H-thymidine suggested significant increase in the labelling of activated, undifferentiated endothelial cells in vascular sprouts and of differentiated endothelial cells in developed capillaries. FGF S3 appeared to speed up the differentiation of freshly formed endothelial cells. Also labelled were pericytes and other fibroblastoid cells, undifferentiated mesenchymal cells, juvenile undifferentiated fibroblasts, mature fibroblasts, myofibroblasts, and macrophages. Pericytes are presumed to be preferential precursors of myofibroblasts, on account of their occurrence in time and similar ultrastructural parameters. Close neighbourhood of lymphocytes and labelled fibroblasts gave rise to the assumption of specific effects, such as stimulation by lymphokines.

Animals↗
PubMed1982

Correlated ultrastructural and morphometric studies on the liver during prenatal development of rats.

Quantitative and qualitative changes in liver tissues during prenatal development were studied by electron microscopy and morphometry. On the 15th day, 30% of fetal liver volume consisted of hepatocytes, and the extrahepatocytic spaces amounted to 63%. The hemopoietic cells occupied 93% of the extrahepatocytic spaces. Immature bile canaliculi were observed and amounted only to 0.14% of extrahepatocytic spaces. The hepatocytes were irregular in shape and possessed several large lipid droplets which amounted to 19% of the cytoplasm. Although the rough surfaced endoplasmic reticulum (RER) was well developed, the smooth surfaced endoplasmic reticulum (SER) was not yet differentiated. The typical peroxisomes with nucleoid and glycogen were not observed in the cytoplasm. On the 18th day the volumetric densities of hepatocytes and bile canaliculi were increased. The typical peroxisomes with nucleoid appeared in the cytoplasm. The accumulation of glycogen which amounted to 12% of the cytoplasmic volume had taken place, while the volume of lipid droplets decreased significantly. In glycogen areas the differentiation of SER began. At birth the histogenesis of the liver was well established. The hemopoietic cells decreased in number and were confined to perisinusoidal spaces. The volumes of biliary capillaries and sinusoids were comparable with these of young rats now. The volumetric density of hepatocytes increased and occupied about 74% of the liver. The volumetric densities of mitochondria, SER, peroxisomes, secondary lysosomes, and lipid droplets increased significantly in comparison with those of the 18 days old fetus, while RER, Golgi area, and primary lysosomes were rather constant. The volumetric density of glycogen decreased rapidly at birth.

Adult↗
PubMed1981

[Electron microscopic findings during hypothermic storage preservation of the liver. II. (author's transl)].

Porcine livers were preserved by simple hypothermic storage for 6 h using plasma-protein-fraction 5%, albumin 5%, Collins C2, and Ringer-lactate followed by a morphometric evaluation of the electron-microscopic changes. The morphometric parameters reflecting swelling of mitochondriae showed the most pronounced changes and were suited best for reproduction. The best result was achieved by using Collins C2-storage. The endoplasmic reticulum was found to be only slightly swollen in all preservation solutions investigated here, at the same time a degranulation of granular endoplasmic reticulum could be demonstrated. The increase in volume of lysosomes per unit-volume was not significant.

Animals↗
PubMed1980

[The significance of electron microscopy for the assessment of membranous glomerulonephritis (author's transl)].

In 35 biopsy specimens taken from 21 patients with membranous glomerulonephritis (mGN) the ultrastructure of the glomeruli was investigated with special regards to the degradation of the immune complexes. Electron microscopy allows the most comprehensive assessment of the manifold basement membrane changes. This is of high value for the practical diagnosis.

Antigen-Antibody Complex↗
PubMed1978

Quantitative ultrastructural characterisation of rabbit erythroblasts and of 3H uridine incorporation into their nuclear components.

Electron microscopic-autoradiographic and morphometric investigations were carried out in erythroblasts from rabbit bone marrow. 1. to obtain quantitative data for the erythroblast classes. 2. to determine quantitative-morphometrically the incorporation rate of 3H uridine into the cell components of the different erythroblast classes. 3. to evaluate the influence of UV irradiation on the incorporation of 3H uridine. According to ultrastructural criteria erythroblasts are divided into 3 classes: basophilic erythroblasts (BE), polychromatic erythroblasts (PE) and orthochromatic erythroblasts (OE). The areas of the 3 classes of erythroblasts are in a ratio of 1:0.5:0.43. In all classes the portion of the nucleus is between 56 and 58.8%. The portion of mitochondria decreases from 13.3% (BE) to 9.3% (PE), and to 6.3% (OE) respectively. Simultaneously the portion of heterochromatin in the nuclear area rises from 24.2% (BE) to 49.8% (PE), and to 63.2% (OE) whereas the percentage of euchromatin decreased correspondingly. Nucleoli were found only in 78% of the BE and in 3.4% of the PE. For the quantitative determination of the silver grains and silver filaments, respectively, the morphometric procedures have been adapted to the particular conditions. So it was necessary to estimate the areas covered by silver grains of filaments. The silver grains or filaments localised in the nuclear area are in the range from 84.6 to 93.4%. The percentage of silver grains of the total cellular area is 14.4% in BE, 6.8% in PE and 4% in OE. In a similar way the relative values of the nucleolus (total) and the euchromatin and heterochromatin are reduced. UV irradiation of bone marrow in vitro for 10 to 20 min does not cause any significant changes in the incorporation of 3H uridine. This result is in contrast to other published experiments on the influence of UV on the RNA synthesis. It is assumed that the irradiation dose was too low to induce a measurable effect on the RNA synthesis or the point of investigation was too early.

Animals↗
PubMed1978

[Comparative study on the dependence of quantitative results in the electron microscopic autoradiography on the type of developer (Microdol X, Phenidon) (author's transl)].

It was the aim of the investigation to compare quantitative results of electron microscopic autoradiographs after the use of different developers (Microdol X, Phenidon) adapting morphometrical methods. Erythroblasts of rabbit were tested after incorporation of 3H-uridine in vitro. Both developers showed the same tendency at higher rates of incorporation (basophilic erythroblasts and polychromatic erythroblasts). Using Phenidon, however, we could obtain only half the values for the individual cell components. At high rates of incorporation Microdol X results in an overlapping of the silver filaments. Thus, more distinct grains can be reached by Phenidon. At smaller rates of incorporation (orthochromatic erythroblasts) after using Phenidon a quantitative evaluation is however influenced by too many factors of uncertainty so that according to our investigations Microdol X is better suited for a quantitative evaluation of electron microscopic autoradiographs.

Autoradiography↗
PubMed1977

[Quantitative and qualitative changes in the heart muscle of the left ventricle in male rats during development and maturation in the first 6 months of life].

In order to characterise the postnatal development and maturation of heart muscle cells the musculature of the left ventricle of male rats has been investigated electronmicroscopically at birth, at the 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 14th, and 21st day of life, as well as after the 1st, 2nd, 3rd, 4th, 5th, 6th month. On the basis of these investigations quantitative and qualitative data have been obtained. The development of the heart muscle cells is characterised by 2 processes. 1. Processes of synthesis and development - The ribosomes/polysomes which are to be found in great numbers are a characteristic of the synthesis of the myofilaments which plays an important role in the 1st phase of postnatal development. This synthesis of myofilaments takes place in the sarcoplasm by the formation of new individual myofilaments, in the interior and at the border of existing myofibrils, and at the level of the Z-lines. Mitochondria are developed in particular by the germination of small mitochondria the percentage of which amounts to about 16% at birth. The sarcoplasmic reticulum is developing in its longitudinal as well as transversal forms only during the 1st month. The disci intercalares, however, have been formed in the main already at birth. Cells are furthermore developing by mitotic processes during the first days. 2. Degradation processes - 2.1. The degradation is characterised by focal autophagocytotic processes in mitochondria concerning the cristae as well as the matrix and the outer membrane. During these processes autophagocytotic vacuoles are developing partly with myelin membranes. In addition, whole mitochondria are transformed into autophagocytotic vacuoles. Later on, mitochondria are also condensed and transformed into mitochondrial lipofuscin. 2.2. The autophagocytotic degradation of glycogen together with the sequestration and formation of vacuoles and myelin membranes are particularly striking. Lipofuscin, however, is to be observed in larger quantities only from the 4th month onwards. The investigations have shown that decisive phases of development can be determined: the day of birth, the 3rd, 4th, 5th, and 7th, and 14th day, as well as after the 1st, 3rd, and 6th month. This determination of the specific developmental phases of the heart muscle makes it possible to carry out investigations in a more economical and purposeful way.

Animals↗
PubMed1976

[Electron microscopic and light microscopic studies of optical and cortical afferents in the lateral geniculate body, pars dorsalis, of albino rats with special attention to synaptic organization].

1. In the CGLd of the albino rat there are to be found two forms of retinal terminals in electronmicroscopic investigations, they are identical with 2a and 2b terminals described formerly in Golgi-preparations. 2. The small 2b terminals are situated previously in the extraglomerular neuropil, which is identical with the terminal part of P-neuron dendrites. They establish asymmetric GRAYtype I contacts with dendrites and spines of the relay-cell-dendrites. 3. The large 2a terminals form filamentous contacts with the smooth surfaces of the dendrites of the stem-and branching-zones. Synaptic contacts (GRAY I) are established with the grape-like appendages in the branching zone of P-neuron dendrites. 4. In the glomeruli of the CGLd there are three main components, which are the nerve endings of large optic axons, the interneuron dendritic terminals and the relay-cell-dendrites. They are surrounded by astrocytic processes. 5. In the extra-glomerular neuropil there are numerous small nerve endings, they form GRAY type I contacts with relay-cell-dendrites and their spines. They are partly identical with the type I endings in Golgi-preparations (cortical terminals). 6. After the eye enucleation and ablation of the visual cortex the type 2a and 2b and type 1 terminals degenerate. There are two forms of degeneration, the light and the dark one. 7. After eye enucleation two forms of degenerations in the degenerating retinal axons occur, which are the "watery" and the "dense" form. Besides the astrocytes the oligodendrocytes remove the destroyed particles. 8. The ultrastructural characteristics of the interneuronal dendritic terminals and their possible funktion are discussed. 9. There is added a table of the synonyma of CGLd structures.

Animals↗
PubMed1976

[Adrenoleukodystrophy. Clinical-pathologic case history and literature review].

This article presents the clinical and pathological history of a 10-year-old boy with adrenoleukodystrophy as well as a tabular survey of 17 additional cases of which the necropsy records were published in the literature. So far as the case of adrenoleukodystrophy directly observed by the authors themselves is concerned, commencement of the disease was in the seventh year of life, with symptoms of Addison's disease and diffuse inflammatory cerebral sclerosis being observed at about the same time. The cerebral disease manifested itself as a progressive pseudobulbar and pyramidal tract symptomatology and as a progressive cerebral psychosyndrome reminiscent of an endocrinal psychosyndrome. Morphologically, the adrenoleukodystrophy was characterized by severe dystrophy of the cortex of the suprarenal gland and the brain are considered the points of action of a still unknown noxa.e suprarenal gland as well as by extensive sudanophilic processes of decomposition in the cerebromedullary substance, putamen, pallidum, and thalamus. Striated cells and cytoplasmic filamentous inclusions observed in the brain and suprarenal glands in a number of cases reported in the literature were not found by the present authors. The cortex of th

Addison Disease↗