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Biomedical subjects

R Fahlbusch

Publications and source records attributed to R Fahlbusch.

At least 235 records · Page 13Linked to original sources
PubMed1985

[Intra- and perioperative acoustic evoked brain stem potentials in cerebellopontile angle operations].

From a series of 35 cases with intraoperative monitoring of acoustic evoked brainstem responses 4 cases with cerebellopontine angle surgery are presented in detail. The aim of neuromonitoring is to provide the surgeon with an additional instrument to assess the functional state of the hearing pathway with objective neurophysiological criteria during dissection near the eighth nerve and brainstem. Thus, a near total loss of potential during a neurovascular decompression of the trigeminal nerve could be reversed by modifying the surgical procedure. In 2 cases of acoustic neurinoma with preserved wave I this peak was obtainable throughout the procedure with a good postoperative result. Transient amplitude attenuation and latency increase was seen with a meningioma, which normalized before the end of operation with good postoperative hearing and brain-stem function. The relationship between intraoperative BAEP changes and postoperative brain-stem and eighth nerve function, and the value of neuromonitoring are discussed with regard to surgery around the internal auditory meatus and the eighth nerve.

Adult↗
PubMed1984

Cytotoxic effects of alkyl-lysophospholipids in human brain tumor cells.

The cytostatic activity of alkyl-lysophospholipids (ALP) was investigated in vitro with cells from 2 astrocytomas, 2 glioblastomas and a meningioma. In all lines the incorporation of [3H]thymidine into the tumor cells was inhibited by ALP. This effect was dependent on the ALP dose and incubation time. Incorporation rates were less than 5-10% of the control rates after an incubation time of more than 48 h with the ALP compound at a concentration of 20 micrograms/ml. 2-lysophosphatidylcholine, the ester-linked lysophospholipid, did not reveal any cytostatic effects. As a morphological criterion for severe cell damage, the trypan blue dye exclusion test was performed. Results were closely correlated with those of the thymidine incorporation inhibition assay. Further morphological evidence for actual damage of the tumor cell, caused by ALP incubation, was obtained by light microscopy of cytocentrifuge preparations and scanning electron microscopy. Membrane defects of tumor cells incubated with ALP were observed both in light and scanning electron microscopy, whereas untreated control cells remained intact. In cytocentrifuge smears of tumor cells, karyorrhexis occurred after 24 h of ALP treatment. After 48 h the cells looked almost completely damaged, and only fragments remained. Microvilli, blebs and ruffles, which indicate high surface activity and are characteristic morphological features of neoplastic astroglial cells in scanning electron microscopy, were severely disturbed by ALP incubation. Finally, the ability of tumor cells to adhere to glass and plastic surfaces was affected.

Antineoplastic Agents↗
PubMed1983

Hyperthyroidism due to a TSH secreting pituitary adenoma: case report, treatment and evidence for adenoma TSH by morphological and cell culture studies.

A 36-year-old woman with recurrent hyperthyroidism, inappropriately elevated serum TSH, and an 8 mm pituitary microadenoma is described. Transsphenoidal adenomectomy rapidly reduced serum TSH to normal and restored the euthyroid state with retention of other anterior pituitary functions. Tissue removed at operation was examined by light and electron microscopy and cell culture. The tissue was neoplastic, composed of irregular often elongated cells which immunostrained positively only with antisera to beta-TSH. The cells contained small granules (100-170 nm) usually along the cell membrane. In cell culture TSH alone was secreted and the rate of secretion declined with time. We conclude that the patient had a TSH secreting microadenoma as a cause of her hyperthyroidism.

Adenoma↗
PubMed1983

[A prolactin-producing microadenoma as the cause of galactorrhea and delayed puberty in an adolescent boy].

The case history of a 16 years old boy with delayed puberty and the sudden onset of galactorrhea is presented. Prolactin analyses and X-ray studies of the sella turcica lead to the diagnosis of a pituitary tumor. A prolactin producing microadenoma was selectively excised via the transsphenoidal route. Serum prolactin resumed normal concentrations within hours after the operation. During the next months the boy showed the signs of normal puberty with increasing concentrations of serum testosterone. Because serum prolactin concentrations remained within the normal range, therapy with bromocriptine was not necessary. A spermiogram however, performed seven months after the operation, showed signs of a viscosipathy and terato-asthenozoospermia.

Adenoma↗
PubMed1982

Spontaneous development of hyperprolactinaemia.

Spontaneous development of hyperprolactinaemia was investigated by measuring prolactin levels in 34 hyperprolactinaemic females with a normal sella turcica, in 19 females with a radiologically proven prolactinoma, and in 19 females with a histologically proven prolactinoma after transsphenoidal surgery. Prolactin levels remained unchanged or declined in 69 patients followed over a period of up to 6 years. In one patient with a normal sella turcica, prolactin levels increased accompanied by the development of a radiologically detectable microprolactinoma. In one patient with a radiologically proven macroprolactinoma the increase of human prolactin (hPrl) levels was accompanied by infiltrative and parasellar prolactinoma growth. One patient showed a dramatic increase of post-operative persisting elevated hPrl levels without radiological changes. These findings suggest that prolactinomas in general have a limited growth potential which should be considered in the management of hyperprolactinaemic patients.

Adenoma↗
PubMed1982

Influence of pregnancies on prolactinomas.

Hyperprolactinaemic patients desiring pregnancy with a normal sella turcica or radiological evidence for a microprolactinoma without suprasellar extension were treated with bromocriptine. Females desiring pregnancy with large adenomas or suprasellar extension were treated by transsphenoidal surgery and in most instances post-operatively with bromocriptine. This differentiated management allowed the outcome of 65 pregnancies with delivery at term without complications related to the sella turcica. Considerable variations of prolactin levels during pregnancy suggesting different oestrogen sensitivity of the prolactinoma cells were encountered. However, a rapid fall of the prolactin levels in 60 patients after termination of pregnancy indicated that oestrogen stimulation does not cause persisting growth of the adenoma. In contrast, in 10% of pregnancies of hyperprolactinaemic patients a reduction of the prolactin levels has been observed leading to spontaneous ovulatory cycles in 5 patients.

Adenoma↗
PubMed1982

Multiple cellular forms of corticotrophs in surgically removed pituitary adenomas and periadenomatous tissue in Cushing's disease.

Transsphenoidally removed samples of pituitary adenomas from 14 patients with Cushing's disease and 5 patients with Nelson's syndrome always contained groups of uniform small ACTH-cells. Antibodies against the pro-opiocortin precursor fragments beta-endorphin, ACTH, and 16k-peptide recognized material in typical adenoma cells. A subpopulation of these cells, varying in number from sample to sample, specifically exhibited alpha-melanotropin immunoreactivity. Most periadenomatous samples showed signs of severe degeneration. Typical Crooke cells only occurred in samples from patients with Cushing's syndrome, but, with this exception, no clear differences between pituitaries of patients with Cushing's and Nelson's syndromes could be discerned. Two other forms of ACTH-immunoreactive cells were observed: rare, single, highly immunoreactive cells, with characteristics of both normal and Crooke cells, and numerous syncytial groups of cells in an advanced state of disintegration, presumably the remnants of hyperplastic follicles. The four different corticotrophs are characterized according to their fine structure and immunoreactivity in this study.

Adenoma↗
PubMed1981

[Hyperprolactinemia in the male: clinical aspects and therapy].

Fifty-seven male patients with hyperprolactinemia have been investigated. Macroadenomas were found in 49 patients of whom 24 had received pituitary surgery before elevated PRL levels were discovered. In 8 patients radiology of the pituitary fossa revealed either evidence of microadenoma or a completely normal sella turcica. Prolactin levels ranged from 582 to 498 000 microU/ml. All patients with macroprolactinomas, including those who had undergone previous surgery, had PRL levels above 5000 microU/ml. Disturbances of libido and sexual potency were prevalent in the majority of patients, less frequently accompanied by gynacecomastia and galactorrhea. However, visual disturbances were the reason for the first visit to the doctor in the majority of patients. Pituitary surgery led to improvement of visual field defects, though prolactin levels were never normalized. Postoperative radiotherapy had no significant influence on PRL levels. In contrast, bromocriptine therapy led, in the majority of patients, not only to improvement of hypogonadal symptoms but also to normalization of PRL levels.

Adolescent↗
PubMed1981

[Pituitary adenomata. Status of diagnosis and therapy (author's transl)].

The advances in pituitary surgery are based on the diagnosis of neuroendocrinological function and the microsurgical operative technique with the help of which pituitary adenomata are approached by the transsphenoidal route in approximately 90% of cases and transcranially in about 10%. On the one hand, hormone-active microadenomata can presently be detected in good time endocrinologically and 80-90% can be removed selectively while retaining the pituitary. On the other hand, it can be shown that the greater the tumor the more frequently hormone excesses persist after the operation. Tumors can be directly visualized in the cranial computer tomogram if they ar not smaller than 5-7 mm. Also, larger extrasellar remains of tumors left after operation can be demonstrated by computer tomography. Larger suprasellar adenomata produce a chiasma syndrome which improves in 80% of patients after transphenoidal operation. The slight operative risk is shown in a total of 737 operations for pituitary adenomata in the last 11 years.

Adenoma↗