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Biomedical subjects

G Blaauw

Publications and source records attributed to G Blaauw.

54 records · Page 3Linked to original sources
PubMed1983

Presence of progesterone receptors and absence of oestrogen receptors in human intracranial meningioma cytosols.

The occurrence of oestrogen and progestin receptors in cytosols from human intracranial meningiomas was studied with a dextran-coated charcoal assay and Scatchard plot analysis. [3H]-Oestradiol and [3H]-promegestone (17 alpha, 21-dimethyl-19-norpregna-4,9-diene-3,20-dione, R-5020) were used as tracers. Using this method, no high-affinity binding sites for oestradiol were observed, whereas progestin binding was identified in 18 out of 20 meningioma cytosols. The number of progestin binding sites was identical in meningioma cytosols obtained from female patients (192 +/- 57 fmol/mg protein, mean +/- S.E.M., n = 12) and those obtained from male patients (230 +/- 57 fmol/mg protein, n = 6), as was the dissociation constant of the complex (1.5 +/- 0.3 vs 1.4 +/- 0.3 nmol/l respectively). Only progestins (progesterone, R-5020 and megestrol acetate) competed successfully with tritiated R-5020. Oestrogens, androgens and cortisol showed no appreciable cross-reaction. It was concluded that the cytosols from human intracranial meningiomas contain progesterone receptors in the absence of oestrogen receptors. The presence of these progesterone receptors may indicate that (anti)-progestational treatment could be of potential value in cases which cannot be treated by surgery alone.

Adult↗
PubMed1983

Carpal tunnel syndrome in childhood.

Two children are reported who had a bilateral carpal tunnel syndrome. In one patient mucopolysaccharidosis IS, in the second mucopolysaccharidosis IV was present.

Age Factors↗
PubMed1980

Subdural cysts and diencephalic tumor.

Four children with diencephalic emaciation, three of whom had subdural cysts (effusions), are described. In two of these cases the initial diagnosis was subdural effusion, which delayed the correct diagnosis. Three of the four patients with emaciation of diencephalic origin had large tumors in which the involved part of the diencephalon accounted for only a small part of the total tumor bulk. The fourth patient had a large glioma of the optic chiasm.

Brain Diseases↗
PubMed1979

Cranial extradural cyst.

A large skull defect due to an extradural collection of clear and colourless fluid in a 59-years-old man is described. Hesitantly, we consider this to be the consequence of skull erosion due to Pacchionian granulations.

Bone Diseases↗
PubMed1979

Radiotherapy in brain-stem gliomas in children.

Twenty-one children with brain-stem glioma are discussed. Sixteen received radiotherapy and five were too sick to be irradiated. The mean survival was 3.4 weeks for the non-irradiated group and 8.7 months for the treated group, two of the latter being still alive five and ten months after diagnosis. From the literature and our cases the effect of radiotherapy in brain-stem glioma in childhood is not clear. Differences in patient-selection criteria and the mode and doses of irradiation between the reported series may account for the divergent results, but in our cases radiotherapy did not prolong survival as significantly as compared with the reported series. Elevated intracranial pressure is not rare in patients with a brain-stem glioma, as may be concluded from the present series and from the literature.

Adolescent↗
PubMed1978

Morphology and origin of arachnoid cysts. Scanning and transmission electron microscopy of three cases.

Three surgically removed primary arachnoidal cysts were studied with scanning electron microscopy (SEM) and two of the cases with transmission electron microscopy (TEM). The cells lining the cyst cavity had microvilli at the surface, true cilia were absent. In the cytoplasm multivesicular bodies, many pinocytotic vesicles, some large vacuoles and strands of tonofilaments were prominent features. The cells were interconnected by desmosome-like junctions and were separated from the surrounding tissue by a distinct but sometimes incomplete basal membrane. Based on these findings it is concluded that arachnoid cysts are derived from the outer arachnoid cells (subdural neurothelium), the formation of the cysts being attributabel to secretory capacity of the subdural neurothelium.

Adult↗
PubMed1976

Carotid ligation for carotid aneurysms.

Thirty patients with subarachnoid haemorrhage due to rupture of a carotid aneurysm were treated by ligation of the common carotid artery. Two patients died as a result of the procedure, two patients developed persisting hemisphere deficit. Eight of the ten patients who developed cerebral ischemia after the operation were operated within ten days after the bleeding. At present out aim is to guide the patient safely through the first ten days after his haemorrhage and perform ligation at the end of the second week. After a follow up period of 1-8 years recurrent haemorrhage did not occur. Common carotid ligation, preferably with control of carotid artery end pressure, cerebral blood-flow and EEG is considered to be a valuable method to treat ruptured intracranial carotid aneurysm.

Adolescent↗
PubMed1975

Cranial venous system and the posterior fossa in spina bifida aperta.

A study of the cerebral venous system in children with S.B.A. was undertaken, and this report concerns the gross structure of this structure of this system in the posterior fossa. Noteworthy is the closeness of the torcular to the foramen magnum. The lateral sinuses ran near to the foramen magnum to the sigmoid sinuses. The dura of the posterior fossa consisted of a plexiform structure in which no clear distinction could be made between various sinus systems normally present in the dural layers of the posterior fossa, thus constituting an occipital plexus. The walls of the sinuses were weak and were vulnerable to mechanical pressure. The foramen magnum of the skulls of children with S.B.A. was larger than in normal children. The distance of the torcular to the ventral margin of the foramen magnum was smaller in S.B.A. This distance remained unchanged at least until nine months of age in normal children as well as in children with S.B.A., although there was an increase in size of the foramen magnum in both with advancing age.

Cranial Fossa, Posterior↗
PubMedDate not supplied

Computed tomography-guided scalp marking of cerebral surface lesions; an alternative to stereotaxis for small convexity lesions.

Marking of the skull prior to craniotomy on the basis of CT images can prove to be a difficult problem. The method reported here essentially consists of a procedure which involves tilting and manoeuvreing the head within the scanner so that the surface marker is perpendicular to the skull at the site of the lesion. This is easy, useful and not time consuming.

Brain↗
PubMedDate not supplied

Progesterone receptor synthesis in human meningiomas: relation to the estrogen-induced proteins pS2 and cathepsin-D and influence of epidermal growth factor, Forskolin and phorbol ester in vitro.

Autonomous expression of progesterone receptors (PR) in human meningiomas is well established. To evaluate whether, similar to progesterone receptors, other estrogen-inducible proteins are also autonomously expressed in meningiomas, concentrations of pS2 and cathepsin-D (Cath-D) were measured in 52 meningiomas. No pS2 protein was detectable in 52/52 tested meningiomas. The Cath-D protein was measurable in all 52 meningiomas, but the mean concentration of Cath-D in meningioma cytosols was 2.4-fold lower than that of a group of 54 breast tumors (p < 0.001). These results indicate that autonomous expression is a PR-related rather than an estrogen receptor-related phenomenon and, consequently, that estradiol is probably not responsible for PR synthesis in human meningiomas. To evaluate the role of other, non-estradiol-dependent signalling pathways in PR synthesis, the effects of EGF, Forskolin and phorbol ester on PR synthesis were tested in vitro. No PR was detectable after the addition of EGF to six different primary cultures. Forskolin and TPA addition caused a morphological change in meningioma cells, but did not induce PR or pS2 synthesis in two different primary meningioma cultures. We conclude that PR synthesis in human meningiomas cannot be triggered by switching on the signalling pathways activated by these growth factors.

Breast Neoplasms↗
PubMedDate not supplied

TP53 mutations in human meningiomas.

Overexpression of p53 has been reported to play a role in the development of neoplasms of the central nervous system. Meningiomas are generally benign intracranial tumors originating from the meninges. Overexpression of the p53 protein in meningiomas and an association with histological type and recurrence has been reported. Mutation of the TP53 gene leads to a more stable p53 protein in quantities high enough for detection by immunohistochemistry. In the search for these mutations the core domain of the TP53 gene of meningiomas has been analyzed. Only a very low incidence of mutations was reported. The apparent discordance between overexpression of p53 protein and TP53 gene mutations may be explained by mutations located outside the core domain. This issue was addressed in the present study. All 11 exons of 17 meningiomas were analyzed for DNA alterations by PCR single-strand conformation polymorphism (PCR-SSCP) analysis with subsequent sequencing. PCR-SSCP analysis showed a various number of band shifts and nucleotide alterations, caused either by alterations in the flanking introns or common polymorphisms (codon 36 and 72). The allele frequencies of the polymorphisms found in this small population of tumors resemble the frequencies reported in the literature. In addition, three nucleotide changes located in introns 2, 3 and 7 were found in 11, 3 and 4, respectively, of 17 specimens. Based on this study and on reports by others we conclude that it is not very likely that TP53 mutations are involved in the etiology of meningiomas.

Adult↗