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Biomedical subjects

V Rothenbühler

Publications and source records attributed to V Rothenbühler.

5 recordsLinked to original sources
PubMed1978

Extracellular growth hormone deposits in pituitary adenoma.

Ultrastrucutral examination of 184 pituitary adenomas demonstrated the presence of extracellular accumulations of electron dense material in 3 out of 64 cases with acromegaly. Fibrillary structures were seen in larger deposits of such material. This material was only observed in biopsies fixed directly with osmium tetroxide; initial fixation with glutaraldehyde did not retain the material and left empty spaces. Positive immuno-histochemical reaction with specific antibodies demonstrated that the extracellular material contained growth hormone (GH). The presence of this extracellular material could not be related to the age or sex of the patient nor to the duration of symptoms, size of the tumor, presence of diabetes mellitus, or concomitant secretion of prolactin. The pericapillary fibrous sheath was heavily thickened in the patient with the longest duration of symptoms, intermediate in thickness in the second and normal in the third.

Adenoma↗
PubMed1977

The size of growth hormone granules in pituitary adenomas producing acromegaly.

Measurements of the diameters of large numbers of granules in electron micrographs of pituitary adenomas in cases of acromegaly do not show that a typical size exists which allows of the retrospective diagnosis of the hormone secreted by the tumour. The granule diameters found in single cases show a normal distribution. The average values determined in 19 unselected cases of acromegaly range between 160 and 342 nm. They are also normally distributed about the mean for the entire group which is 238 nm. With histo-immunological electron microscopic techniques h GH can be demonstrated in small, medium and large granules. The size of hormone granules is determined by functional factors such as the speed of hormone synthesis and hormone release but not by the type of hormone secreted.

Acromegaly↗
PubMed1977

Pituitary adenoma calcification.

Calcifications have been found in 9 of 137 different pituitary adenomas (6.6%) that have been examined with skull roentgenograms, light microscopy, and electron microscopy. Electron microscopy was most efficient because seven cases showed positive findings. Skull x-ray films showed calcification in four and light microscopy in only two cases. Six adenomas showed signs of increased prolactin production (either by direct determination or presence of galactorrhea). Two pateitns with calcifications on skull x-ray films and negative microscopic examinations did not show signs of any hormone secretion. The ultrastructural examination showed that the process of calcification started in single necrotic cells undergoing fibrillary transformation. No large areas of necrosis were present as seen in other forms of dystrophic calcification. The deposits consisted of dense accumulation of radially oriented hydroxyapatite crystals. The observations suggest that local factors and the type of hormone secreted may play an important role in the calcification pattern of pituitary adenomas.

Adenoma↗