Search PubMed⌕ Search

Biomedical subjects

U Heinzmann

Publications and source records attributed to U Heinzmann.

72 records · Page 4Linked to original sources
PubMed1982

X-ray induced dysplasia in the developing telencephalic choroid plexus of mice exposed in utero.

Pregnant NMRI-mice were X-irradiated with single doses of 0.95 Gy (100 R) and 1.9 Gy (200 R) on day of gestation (dg) 12. For sampling, anesthetized animals were perfused with buffered glutaraldehyde solution or fixed by immersion in Karnovsky solution. LM, SEM, and TEM studies were carried out on brains prenatally and up to the age of 20 months to follow the radiation effects on the developing lateral choroid plexus. Radiation-induced changes were found using all three methods and at all stages studied. The normally sickle-shaped and stretched choroid plexus is shortened and irregular, and the dome-shaped plexus cells are flattened. Their superficial fine structures, i.e., the microvilli and cilia, are altered. Three stages of severity can be distinguished and the internal hydromicrocephalus increases from stage I to III. Intercellular spaces of the treated plexus epithelium are often dilated, but the tight junctions at the ventricular surface seem to be intact. The interstitium shows large dilations in comparison with the controls. Thus, gross changes and alterations in the fine structure can be induced in the choroid plexus by doses of 0.95 Gy and 1.9 Gy, which persist throughout postnatal life.

Animals↗
PubMed1976

[Histochemical and histological investigations on the human fallopian tube under different hormonal influences. I. Demonstration of ATPase with special reference to reactive ciliated cells (author's transl)].

The localization of the Mg++-activated adenosine triphosphatase (ATPase) in the human Fallopian tube has been studied by means of histochemical methods. The samples were obtained from 18 women in the age from 23--62 years. Some of them were treated by various steroid hormones. Endosalpinx ciliary ATPase-activity represents dynein and is therefore an indicator of ciliary motility. Estrogens and gestagens have a different influence on the ATPase-activity. All cilia of one ciliated cell react in the same manner and may be regarded as a reaction unit. The relation of negative to positive ciliary borders differs characteristically in the tubal isthmus, ampulls and infundibulum and coincides with commonly known phenomena of egg transport through the oviduct. Postovulatory, reaction units increase in ampulla and infundibulum compared with the proliferative phase. The oviducts of postmenopausal women possess but a scanty outfit of reaction units. Short-time treatment with estrogen in the early secretory phase results in a great number of reaction units in all tubal segments; a similar treatment in the proliferative phase diminishes the reaction units in the ampulla. Midcycle progesterone treatment activates the ciliary ATPase in the isthmus. Low doses of lynestrenol (minipill) in the proliferative phase leads to a decrease of reaction units in all tubal segments; the pattern of ciliary reaction under low doses of lynestrenol at the time of ovulation coincides with that of the proliferative phase. Treatment with a contraceptive steroid (0,05 mg ethinylestradiol and 0,25 d-norgestrel) causes a considerable activation of the ciliary ATPase in all portions of the oviduct.

Adenosine Triphosphatases↗
PubMedDate not supplied

Imaging of immunolabeled membrane receptors in uncoated SEM specimens.

Epidermal growth factor receptors (EGFR) were labeled with 10 nm immunogold and examined on uncoated specimens of A431 human epidermoid carcinoma cells. A field emission gun and a high-sensitivity YAG ring detector were used to demonstrate the affinity labeling simultaneously in the secondary-electron (SE) and backscattered-electron (BSE) modes with a low accelerating voltage (Vo). At Vo = 2 kV, the SE and BSE signals were too weak to identify all markers, while at Vo = 3-7 kV labeling was observed unambiguously in both the SE and BSE modes with smaller and higher working distances. Increasing the Vo to above 7 kV sometimes provokes instability of the specimens. A Vo of > or = 10 kV produces charging artifacts in the SE image, but permits a BSE image of the gold markers providing additional topographic information. In conclusion, immunogold labeling can be used with good results for uncoated specimens.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Post-mortem volume measurements of limbic system and basal ganglia structures in chronic schizophrenics. Initial results from a new brain collection.

Volumes of the hippocampal formation, external and internal pallidum, caudate, putamen, and nucleus accumbens were measured in both hemispheres of recently collected post-mortem brains of 18 chronically ill schizophrenics and 21 control subjects. In the schizophrenic group, the hippocampal formation and the internal pallidum were significantly smaller in the right and left hemisphere, whereas external pallidum, putamen, caudate and accumbens were not significantly changed. Volumes of the hippocampus and of all evaluated parts of the basal ganglia were in the male schizophrenics more reduced than in the female patients. The right and left hemispheres were equally affected in both sexes. Since the mean brain weight was in patients and controls nearly identical, the volume differences can not be explained by a general brain atrophy or hypoplasia but rather indicate a more focal lack of brain tissue, by which some clinical features of the disease might be explained.

Adult↗
PubMedDate not supplied

Vascular corrosion casts of the nasal mucosa. An experimental study in the rabbit.

Ten-rabbits of either sex, weighing between 1.8 and 2.7 kg were used for studies on the angioarchitecture of the nasal mucosa of the septum and the anterior concha. Via the common carotid artery, Batson's corrosion compound No. 17 was introduced into the vascular system of the nose after rinsing with Ringer's solution. After digesting the connective tissue between the vessels, vascular corrosion casts were obtained. The replica of the endonasal angioarchitecture offers a unique opportunity to examine the various vascular layers of the nasal mucosa as well as the junction and relationships between different vessels in the different levels of the tunica propria. Our results can be regarded as a useful extension of earlier investigations in this field.

Animals↗
PubMedDate not supplied

Distribution of disialoganglioside GD2-antigen and binding of anti-GD2 antibodies on spheroids of neuroblastoma cell line.

The ganglioside GD2 is highly expressed on human tumors of neuroectodermal origin. We investigated by scanning electron microscopy the ganglioside GD2 distribution on the surface of spheroids of the neuroblastoma cell line SK-N-LO. About 50% of cells showed GD2 on the plasma membrane and the distribution of GD2 on most of these cells was heterogeneous, with more GD2 at the contact sites of the cells. The binding kinetics of the chimeric anti-GD2 antibody ch14.18 labelled with I-125 on spheroids (average diameter: 450 microns) was determined by gamma counting. Over 4 hours the antibody concentration was raised substantially but up to 24 hours there was only a very slow further increase. A clustered pattern of bound chimeric anti-GD2 antibody ch14.18 was found on a cross-section of the spheroid by autoradiography.

Antibodies, Monoclonal↗