Presenile Alzheimer dementia characterized by amyloid angiopathy and large amyloid core type senile plaques in the APP 692Ala-->Gly mutation.

Mutations at codons 717 and 670/671 in the amyloid precursor protein (APP) are rare genetic causes of familial Alzheimer's disease (AD). A mutation at codon 693 of APP has also been described as the genetic defect in hereditary cerebral hemorrhage with amyloidosis of the Dutch type (HCHWA-D). We have reported a APP692Ala-->Gly (Flemish) mutation as a cause of intracerebral hemorrhage and presenile dementia diagnosed as probable AD in a Dutch family.

Signet-ring cell oligodendroglioma--report of two cases and discussion of the differential diagnosis.

Two cases of oligodendroglioma consisting largely of signet-ring cells were analyzed histopathologically, immunohistochemically and at the ultrastructural level. The signet-ring cells were negative for a panel of tumor lineage markers including glial fibrillary acidic protein, and were negative for Ki-67 (MIB-1 immunohistochemistry). In contrast with the abundance of lysosomal structures reportedly present in the so-called eosinophilic granular cells in oligodendrogliomas, degenerating mitochondria were mainly seen in the cytoplasm of the signet-ring cells.

Cytogenetic, molecular genetic and pathological analyses in 126 meningiomas.

In a series of 126 meningiomas, tumor and patient characteristics were investigated and statistically analyzed. A combined cytogenetic and molecular genetic approach was used to study chromosomal abnormalities and loss of markers on chromosome 22q. This approach was successfully applied to 93 meningiomas.

Familial occurrence of polymorphous oligodendroglioma.

A case of familial polymorphous oligodendroglioma, occurring in a brother and sister, is presented. Polymorphous oligodendrogliomas have a characteristic histopathology consisting of scattered multinucleated giant cells against a typical oligodendroglial background. The oligodendroglial character of the tumors was underlined by positive immunostaining for antigalactocerebroside, anticarbonic anhydrase, and anti-leu-7, without expression of glial fibrillary acidic protein.

Nasopharyngeal presentation of pituitary tumors. Differential diagnosis and treatment.

The intranasal presentation of pituitary tumors is rare. We describe six patients with supposedly intranasal carcinomas, treated by surgery, local chemotherapy, and/or radiotherapy. Because of the favorable clinical course, immunohistochemical reexamination of tumor tissue was done, which showed a macroprolactinoma in four and a nonfunctioning pituitary adenoma in two patients.

The pleomorphic xanthoastrocytoma and its differential diagnosis: a study of five cases.

Five brain tumors with the histopathologic features of pleomorphic xanthoastrocytomas (PXAs) are presented. Computed tomography scans showed a remarkable homology. Two cases had atypical localizations for a PXA, while one 46-year-old patient did not conform to the normal age distribution of this tumor.

Ultrastructural and immunohistochemical segregation of gemistocytic subsets.

Gemistocytes are frequently encountered in cases of reactive gliosis as well as in glial tumors. Recently, miniature forms of gemistocytes (minigemistocytes) were recognized as cellular constituents of oligodendrogliomas. Antibodies specific for the intermediate filaments glial fibrillary acidic protein and vimentin are reactive with gemistocytic cells, but do not react specifically with these cells.

Prognostic implications of glial fibrillary acidic protein containing cell types in oligodendrogliomas.

In oligodendroglial tumors the intermediate filament glial fibrillary acidic protein (GFAP) may be expressed by cells with the morphologic characteristics of typical oligodendrocytes (gliofibrillary oligodendrocytes [GFOC]) and by miniature forms of gemistocytes (minigemistocytes) as well. These latter cell types have been regarded as transitional cells that represent intermediate forms between an oligodendroglial and an astrocytic phenotype. Furthermore, in oligodendrogliomas GFAP may be expressed by intermingled classic large gemistocytes, which are not considered transitional cells.

Computed tomography-guided and stereotactic techniques in the diagnosis and treatment of cerebral tuberculoma.

The advantages of computed tomography-guided preoperative localization of brain lesions are illustrated in four cases of solitary tuberculoma and in one case of tuberculous abscess of both the cerebrum and the cerebellum. The role of stereotactic diagnostic techniques is emphasized. The clinical presentation and the computed tomography findings in these patients were equivalent to those from glial or metastatic tumors.

The influence of the extent of surgery on the neurological function and survival in malignant glioma. A retrospective analysis in 243 patients.

A retrospective analysis was performed on 66 patients with anaplastic astrocytoma (AA) and 177 patients with glioblastoma multiforme (GM). The prognostic importance of age, performance status, tumour location, extent of surgery and radiation treatment was studied. Radiation therapy gave a significant improvement in survival in both AA (p less than 0.

[Intracranial tuberculoma, a special space-occupying process].

In four men and in one woman we found an intracranial local tuberculous infection (4 tuberculomas and 1 tuberculous abscess) in the period 1982-1988. Clinical presentation and computer tomography do not allow discrimination of intracranial tuberculomas from other space-occupying lesions. The value of the stereotactic biopsy for the diagnosis is emphasized and some characteristics of this intracranial process are discussed.

Heterogeneity of growth hormone (GH) release by individual pituitary adenoma cells from acromegalic patients, as determined by the reverse hemolytic plaque assay: effects of SMS 201-995, GH-releasing hormone and thyrotropin-releasing hormone.

We used the reverse hemolytic plaque assay to study the dynamics of GH secretion by individual pituitary adenoma cells from eight acromegalic patients. There was a considerable variation between the adenomas with respect to the percentages of GH-secreting cells (25-78.5%) and also with respect to the amount of GH released per individual pituitary adenoma cell (mean plaque areas varying from 901-3559 micron 2).

Basilar artery giant fusiform aneurysms caused by congenital defect of the internal elastic lamina and media.

Giant fusiform aneurysms of the basilar artery were found in a 6-year-old boy who subsequently died after rupture of the aneurysm, and in a 64-year-old man who showed signs of ischemia and compression of the brain stem. Autopsy disclosed strikingly similar abnormalities of the wall of the basilar artery, consisting of a defect of the internal elastic lamina and absence of the media. A congenital anomaly may play a role in the pathogenesis of this abnormality, in both young and some elderly patients.

The effects of bromocriptine, thyrotropin-releasing hormone, and gonadotropin-releasing hormone on hormone secretion by gonadotropin-secreting pituitary adenomas in vivo and in vitro.

The characteristics and dynamics of hormone secretion in vivo and in vitro were investigated in six patients with gonadotropin-secreting pituitary adenomas. All six tumors secreted and contained FSH and different combinations of LH, beta-LH, and alpha-subunit. In addition, immunohistochemical examination of the pituitary tumor tissue showed staining with both LH and FSH in three and either LH or FSH in the other three tumors.

High incidence of somatostatin receptors in human meningiomas: biochemical characterization.

Thirteen human meningiomas were tested for their content of specific somatostatin (SRIH) receptors using an in vitro binding assay with meningioma homogenates as well as receptor autoradiography. All tumors had measurable amounts of somatostatin receptors. Receptor density, however, greatly varied among the tumors, ranging from low levels to more than 400 fmol/mg protein.

The sensitivity of growth hormone and prolactin secretion to the somatostatin analogue SMS 201-995 in patients with prolactinomas and acromegaly.

The somatostatin analogue SMS 201-995 has recently been shown to be effective in suppressing GH secretion in most acromegalic patients. In the present study it was investigated whether PRL release in prolactinoma and acromegalic patients might also be sensitive to SMS 201-995 and whether co-secretion of PRL in acromegaly plays a role in determining the sensitivity of GH secretion to SMS 201-995. The s.

Delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage: clinicoanatomic correlations.

Fifty-seven of 176 prospectively studied patients with aneurysmal subarachnoid hemorrhage (SAH) developed delayed cerebral ischemia. Clinical features included hemispheric focal signs (13), decrease in level of consciousness (14), or both (30), and mutism (15). Forty-seven patients showed hypodense lesions on CT in one (19) or multiple vascular territories (22), or diffusely in one or both hemispheres (6).

Intracerebral malignant schwannoma.

A case of highly malignant primary intracerebral schwannoma is presented in a boy aged 15 years. The histological, ultrastructural and immunocytochemical properties were consistent with a partly epithelioid schwannoma. All reports so far published of 18 intracerebral schwannomas were of benign tumors, one case was semi-malignant.

Congenital malformations of the spinal cord without early symptoms.

Description of 11 patients with congenital malformations of the spinal cord. Six of them were males, five females and the age varied from 7 to 70 years. Most of these cases produced clinical neurological signs indicating spinal cord disease in later life during an intercurrent disease.

Pyruvate kinase inhibition in the diagnosis of gliomas with an intermediate degree of malignancy.

The aim of the investigation was to see if the histological diagnosis of brain tumors showing an intermediate degree of malignancy can be improved by the measurement of L-alpha-alanine inhibition of pyruvate kinase isoenzymes. The inhibition of pyruvate kinase activity was measured in 51 gliomas with different grades of malignancy. It was confirmed that benign tumors have a low level of inhibition (less than 50%) and that the more malignant the tumor, the higher the level of inhibition became, reaching more than 75%.

Monoclonal antibody selectively reactive with myelin sheaths of the peripheral nervous system in paraffin-embedded material.

We have produced a monoclonal antibody (PM43) selectively reactive with formalin-fixed paraffin-embedded peripheral nervous system (PNS) myelin. The hybridomas were generated by fusion of mouse myeloma cell line Sp2/0 with spleen cells of BALB/c mice immunized with cultured human melanocytes. Hybridomas were screened by the indirect immunoperoxidase assay.

Different responses of growth hormone secretion to guanfacine, bromocriptine, and thyrotropin-releasing hormone in acromegalic patients with pure growth hormone (GH)-containing and mixed GH/prolactin-containing pituitary adenomas.

There is great variability in the GH secretory responses to different stimuli in patients with acromegaly. In the present study, we compared the effects on GH secretion of two compounds (bromocriptine and TRH), which presumably act directly at the pituitary level, with the effect of the centrally acting alpha-adrenergic agonist guanfacine in 14 untreated acromegalic patients. These in vivo responses of GH release were correlated with the results of immunocytochemical studies of the pituitary adenomas.

Oncocytic variant of choroid plexus papilloma.

Two cases of oncocytic plexus papilloma are presented which were in the fourth ventricle and cerebello-pontine angle in women aged 70 and 63 years, respectively. The cytoplasm of the transformed tumor cells was enlarged, eosinophilic, and granular; and it was characterized ultrastructurally by innumerable mitochondria. Most of them had lamellar cristae, a clear matrix, and contained dense granules.

Hereditary neuralgic amyotrophy. Clinical, genetic, electrophysiological and histopathological studies.

Clinical, genetic, electrophysiological and histopathological studies in a four-generation family with hereditary neuralgic amyotrophy (HNA) are described. Clinically two kinds of attack could be distinguished: (1) the classical type with pain and weakness lasting for weeks to months, leaving atrophy and sometimes residual weakness; 2) attacks consisting of recurrent pain and weakness lasting for a few days and occurring about once a week for several months, also resulting in persisting atrophy and weakness. Genetically a strong association was found between HNA and hypotelorism, probably due to pleiotropism of one single gene.

The role of prolactin in the inhibitory action of bromocriptine on growth hormone secretion in acromegaly.

Unlabelled: Bromocriptine treatment results in clinical improvement and inhibition of plasma GH levels in only part of the acromegalic patients. The possible role of the simultaneous presence of Prl and GH in GH-secreting pituitary adenomas was investigated with regard to the inhibitory action of bromocriptine on GH secretion and the paradoxical increase of GH release in reaction to TRH. Surgically obtained pituitary tumour tissue from 35 consecutive acromegalic patients was studied immunohistochemically.