[Procedures in instability of the operated mobile segment following lumbar intervertebral disk surgery].
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Bone Screws↗
Biomedical subjects
T M Markwalder
Publications and source records attributed to T M Markwalder.
Hormonotherapy of meningiomas with medroxyprogesterone acetate. Immunohistochemical demonstration of the effect of medroxyprogesterone acetate on growth fractions of meningioma cells using the monoclonal antibody Ki-67.
The effect of medroxyprogesterone acetate (MPA) on growth fractions of ex vivo meningiomas is demonstrated in using the Ki-67 monoclonal antibody in three cases of meningiomas operated on in two stages and in meningioma specimens from a group of eight patients operated on in one single stage after MPA therapy. Growth fractions in samples from five meningioma patients not treated with MPA were determined for comparison. In the three cases of two-stage operation of the tumors, the percentage of Ki-67-positive cells in meningioma tissue was lower by a factor of 6, 5, and 3, respectively, after MPA therapy. In meningioma specimens from patients receiving no MPA therapy, Ki-67-positive cells were present in 1.02 +/- 0.48%; in samples from MPA-treated tumors the percentage of Ki-67-positive cells was 0.41 +/- 0.40 (different at p less than 0.02 [Wilcoxon's test]). In comparison to our previously published data on untreated meningiomas analyzed for progesterone receptors (PR), MPA significantly reduced the PR activity. There was no obvious correlation between PR activity and potential suppression of the tumor growth fraction. It is concluded that MPA is attractive because it reduces the growth fractions of most meningiomas and might be suitable for adjuvant hormonotherapy.
Antibodies, Monoclonal↗
[Brachialgia of radicular origin aand its treatment].
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Brachial Plexus Neuritis↗
Endocrine manipulation of meningiomas with medroxyprogesterone acetate. Effect of MPA on receptor status of meningioma cytosols.
Fifteen patients with intracranial or spinal meningiomas have been treated with the semisynthetic progestational agent medroxyprogesterone acetate (MPA, Depo-Provera) prior to surgical removal of the tumors in order to investigate the influence of MPA on the progesterone receptor (PR) status of meningioma cytosols. MPA acted as a competitive binder to meningioma-PR: The mean PR values were 15.6 fmol/mg protein (range 0-69) and 338.3 fmol/g tumor (range 0-1190), respectively. In comparison, mean PR values of our untreated meningioma series (n = 58) were 54.9 fmol/mg protein (range 0-586) and 2813 fmol/g tumor (range 0-17,168), respectively. In cases of two-stage resection of meningiomas MPA significantly decreased PR activity in the cytoplasm of meningioma cells. We conclude that MPA binds to meningioma PRs, however, its effect on the growth rate of meningiomas has still to be elucidated.
Cytosol↗
Failure to demonstrate a vasoconstrictive effect of vasopressin on the internal carotid and middle cerebral arteries: a transcranial ultrasound Doppler study.
Vasopressin (AVP) was infused into four healthy human volunteers to explore by Doppler ultrasound the vasoconstrictive action of AVP on the internal carotid (ICA) and the medial cerebral artery (MCA, transcranial Doppler technique). Although AVP levels rose to 74.2 pg/ml (+/- 13 pg, SEM) no significant changes of flow velocity were observed in the ICA as well as the MCA. There was no effect on the pulsatility index of the MCA velocity profile indicating that peripheral vascular resistance remained unchanged during AVP infusion. These results do not support an effect of AVP at high physiological levels on the vascular diameters of the ICA, MCA and cerebral arteriolar system in humans.
Adult↗
Clinicopathological relations of cerebral cavernous angiomas: observations in eleven cases.
Eleven cases of cerebral cavernous angiomas (cavernomas) were observed within a period of 3 years. Two patients presented with cerebral hemorrhage, five with epilepsy, three each with a progressive focal neurological deficit, and one with papilledema. The unruptured lesions had a heterogeneous density on computed tomography with relatively little contrast enhancement. Two lesions contained major cysts. In one of these cases, the cyst measured 5.5 cm in diameter, had an enhancing membrane, and was surrounded by brain edema. Angiography did not show hypervascularity in any instance. During exploration and histological processing, special attention was paid to signs of previous silent hemorrhages and to the degree of encapsulation of the lesion. Iron deposits (signs of previous hemorrhages) were seen to varying degrees inside all cavernomas as well as in the surrounding gliotic cerebrum, and a causal relation between iron deposits and epileptic seizures seems likely. Encapsulation was minimal with the ruptured cavernomas and particularly prominent with the cystic lesions. The membrane of the giant cystic lesion with peripheral brain edema had a histological structure similar to that of the membranes of chronic subdural hematomas. It is suggested that continuous growth of cavernoma cysts is the result of recurrent hemorrhages from sinusoids of the malformation and from the neocapillary network of the cyst membranes.
Adolescent↗
Influence of neomembranous organisation, cortical expansion and subdural pressure on the post-operative course of chronic subdural haematoma--an analysis of 201 cases.
The post-operative clinical course of a series of 201 patients with chronic subdural haematoma has been analyzed with respect to neomembranous organisation, cortical expansion and subdural pressure in the form of a prospective (53 cases) and retrospective (148 cases) study. With the exception of one patient (primary craniotomy and membranectomy) all other 200 cases were treated according to a standardized treatment protocol consisting of burr-hole craniotomy with (170 cases) or without (30 cases) closed-system drainage. Post-operative mortality (within one month after surgery) was 2%. There was a 4.5% recurrency rate and a 2% infection rate. Morbidity solely related to chronic subdural haematoma was 2% and was characterized by a mild neurological deficit. The level of subdural pressure had no influence on the post-operative clinical course, whereas marked intra-operative cerebral re-expansion favoured a more rapid clinical improvement. Although standard deviations were within a broad range, a nearly linear inverse relation could be assumed between the amount of peri-operative cerebral expansion and the degree of neomembranous organisation of the haematomas. Subdural neomembranes seem to represent the crucial opponents to cerebral re-expansion and they prolong the duration of neurological restitution.
Aged↗
Estrogen and progestin receptors in acoustic and spinal neurilemmomas. Clinicopathologic correlations.
Estradiol and progestin receptors were studied in 20 patients with neuraxial Schwann cell tumors, and their presence was correlated to the clinicopathologic features and the amount of preoperative corticosteroid therapy. Based on an arbitrary cutoff value of 200 fmol per gram of tumor as indicative of a positive receptor value in breast cancer, 4 and 13 of the neurilemmoma tissue samples could be considered as positive for estrogen and progesterone receptors, respectively. Whereas there was no convincing correlation between the estrogen and progestin receptor activity and the age, sex, or menopausal status of the patients, overweight patients had significantly higher estrogen and progestin binding values. The correlation between the amount of preoperative prednisone therapy and the amount of [3H]estradiol and [3H]promegestone binding revealed no dose relationship. Correlating [3H]estradiol and [3H]promegestone content with the histologic type of the schwannomas (Antoni types A and B, respectively), we were not able to draw conclusions, because of the predominance of Antoni type A over Antoni type B tissues in our material. The necessity of nuclear receptor assays, ligand specificity testing, and in vitro studies is stressed as a prerequisite for answering the questions whether neurilemmomas contain genuine sexual steroid hormone receptors and whether these receptors are regulated via an estrogen-estrogen-receptor system as is the case in classical sexual steroid hormone target tissues.
Adult↗
Antiestrogenic therapy of meningiomas--a pilot study.
Six patients with inoperable, nonoperative, or recurrent meningiomas were treated with the antiestrogenic agent tamoxifen (Nolvadex) during an 8-12-month period. Computer tomographic, scintigraphic, and clinical evidence of an unspecific tumor response was only encountered in one patient after 4 months of therapy with tamoxifen. The 2-year results did not indicate a favorable response to antiestrogenic treatment. The significance of sex-steroid receptors and their possible prognostic value in endocrine therapy of meningiomas is discussed.
Aged↗
Chronic subdural hematomas: to drain or not to drain?
A consecutive series of 21 adult patients with chronic subdural hematoma was studied in respect to postoperative resolution of subdural collections and clinical improvement after burr hole evacuation without subdural drainage. This series was compared to a previously studied series of patients with chronic subdural hematoma in whom postoperative closed system drainage had been installed. Using the identical protocol for treatment and postoperative follow-up, we obtained identical results with respect to time-related neurological improvement and persistence of subdural collections in the undrained and drained series, except that the steadily progressive clinical improvement during the early postoperative phase (24 hours) in all cases of the drained series was not universal in the undrained cases. Our study suggests that, to avoid the possibility of early postoperative clinical deterioration, burr hole craniostomy and closed system drainage is advisable. We think that subdural drainage is not necessary when the installation of the drainage system seems to be technically difficult, as it may be in cases with considerable perioperative cortical expansion.
Adult↗
Operative management of 194 cases of combined maxillofacial-frontobasal fractures: principles and surgical modifications.
The treatment modalities and results of 346 cases of frontobasal and midface fractures, 194 of which had to be managed by surgery, are reported, and the operative results are evaluated. The importance of an early one-stage operative repair of combined frontobasal-maxillofacial fractures is stressed. The indications for the pure transethmoidal, combined transethmoidal-transfrontal, and single neurosurgical handling of these patients are analyzed. Important surgical modifications that are decisive in the operative management of these fractures are described.
Cerebrospinal Fluid Rhinorrhea↗
Dependency of blood flow velocity in the middle cerebral artery on end-tidal carbon dioxide partial pressure--a transcranial ultrasound Doppler study.
The end-tidal carbon dioxide partial pressure (PCO2) response curves for the flow velocity in the middle cerebral artery were studied in 31 normal subjects with transcranial Doppler techniques. An exponential curve with an exponent of 0.034 mm Hg-1 was found to be a good fit to the recorded data. By means of this relationship, recordings of flow velocity in cerebral arteries can be normalized to a standard value of PCO2. Physiological aspects of cerebrovascular reactivity to PCO2 and the clinical implications of the PCO2 response curve are discussed. The normal material provides a reference for assessing pathological responses.
Adolescent↗
Estrogen and progestin receptors in meningiomas: clinicopathological correlations.
Estradiol and progesterone receptors were studied in 44 patients with meningiomas and correlated to the clinicopathological features and amount of preoperative corticosteroid therapy. Thirty-four (77%) of the meningiomas contained high titers of specific high-affinity cytosol [3H]promegestone (R 5020) binding sites (mean 2,902 fmol/g tumor; range 0-9,598 fmol/g tumor) whereas only miniscule amounts of a nonspecific cytoplasmic [3H]estradiol binding component (mean 48 fmol/g tumor; range 0-201 fmol/g tumor) were detectable. No nuclear binding activity for [3H]estradiol was demonstrable. There was no convincing correlation between high PR activity and the age, sex, or menopausal status of the patients. The correlation study between the amount of preoperative corticosteroid therapy with the amount of [3H]promegestone binding revealed no dose relationship. Correlating [3H]promegestone content with the histologic type, we found 96% of meningothelial, 71% of transitional, and 40% of fibroplastic meningiomas to contain progesterone receptors. The necessity of in vitro studies is stressed to assess the biosynthesis and biological activity of the progesterone receptor in meningiomas, which is apparently not estrogen regulated, as is the case in other estrogen target tissues.
Cytosol↗
Biological expression of steroid hormone receptors in primary meningioma cells in monolayer culture.
Primary meningiomas have been grown in monolayer culture and tested for the presence of steroid hormone receptors and sensitivity to various steroids and steroid antagonists. None of the 10 solid tumors or the primary cultures derived from them contained estrogen receptors, either in the cytoplasm or in the nucleus. Progesterone receptors were present in 50-70% of the solid tumors and some of the primary cultures. Four of four and five of five primary cultures contained, respectively, androgen and glucocorticoid receptors. When one of the primary cultures was tested for growth sensitivity to estrogen, tamoxifen, progesterone, hydrocortisone, and dihydrotestosterone, the last two had noticeable stimulatory effects on growth by day 5. Interestingly, only androgen and glucocorticoid receptors were present in the primary tumor cells in culture, suggesting that these receptors mediated the effects of their respective hormones on growth.
Cells, Cultured↗
Sexual steroid hormone receptor assays in human astrocytomas.
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Astrocytoma↗
Estrogen and progesterone receptors in meningiomas in relation to clinical and pathologic features.
Tumor estradiol and progesterone binding sites were studied in 34 patients with meningioma. Twenty of the meningiomas contained very low titers (mean, 45 fmol/g of tumor; range, 0-201 fmol/g of tumor) of a nonspecific cytoplasmic [3H]estradiol binding component, whereas 26 of the tumors contained high titers of specific high-affinity cytosol [3H]promegestone (R5020; progesterone) binding sites (mean, 1476 fmol/g of tumor; range, 0-8328 fmol/g of tumor). No nuclear binding activity for [3H]estradiol could be detected in 12 of the 34 meningiomas studied, irrespective of the progesterone binding activity. There was no correlation between high progesterone binding activity and the age or the sex of the patient, nor between tumor location and cellular mitotic index. However, progesterone binding activity was present more frequently in meningothelial (95%, 18/21 patients) than in transitional (55%, 5/9 patients) or fibroplastic (25%, 1/4 patients) tumor histologic types. These data suggest that the cellular biosynthesis of the progesterone binding component in meningiomas is not estrogen regulated as it is in other classic estrogen target tissues, such as the breast.
Adolescent↗
Acute cerebrovascular accident after treatment with cis-platinum and methylprednisolone.
A 53-year-old woman with recurrent ovarian cancer sustained an intracerebral hemorrhage after the 4th course of a chemotherapy regimen which included cis-platinum (DDP). She received high-dose methylprednisolone as an antiemetic along with the DDP. No metastases or abnormal vascularity were found on histological examination of the right frontal lobe which had been removed surgically. Causes of cerebrovascular accidents during and following chemotherapy are discussed.
Antineoplastic Combined Chemotherapy Protocols↗
Acute painful cavernous sinus syndrome in unruptured intracavernous aneurysms of the internal carotid artery. Possible pathogenetic mechanisms.
Three cases of painful ophthalmoplegia with acute onset due to an unruptured aneurysm of the intracavernous portion of the internal carotid artery are reported. The possible pathogenetic mechanisms responsible for this unusual mode of clinical manifestation are discussed and the neurovascular relationships of the cavernous sinus are analyzed in respect of ischemic versus compressive damage to the intracavernous neural structures.
Abducens Nerve↗