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Biomedical subjects

G T Bots

Publications and source records attributed to G T Bots.

At least 37 records · Page 2Linked to original sources
PubMed1989

Optic glioma with intraocular tumor and seeding in a child with neurofibromatosis.

We treated a 3-year-old boy with neurofibromatosis who had an optic glioma, intraocular extension with seeding, and iris tumors. On the basis of results of ultrasonography, computed tomography, magnetic resonance imaging, and fine needle aspiration, other intraocular and orbital tumors were excluded. Because of the malignant intraocular aspect, the optic nerve glioma was extirpated. Histologic examination confirmed the diagnosis of an optic nerve glioma with intraocular extension, seeding, and iris nodules. In this juvenile pilocytic astrocytoma with secondary perineural fibrous hyperplasia, several mitoses were found in the orbital and intraocular parts. In the optic canal, three small islands were found that were compatible with the diagnosis of malignant astrocytoma, grade 3. The iris nevi appeared as iris pits and not like the Lisch nodules typical of neurofibromatosis. Café au lait spots were present on the skin. The family history was positive for neurofibromatosis. The results of this study demonstrate that optic gliomas are true astrocytomas and not hamartomas, and have a continuous scale from benign to malignant differentiation.

Child, Preschool↗
PubMed1989

Somatic pairing of chromosome 1 centromeres in interphase nuclei of human cerebellum.

Interphase nuclei isolated from paraffin-embedded tissue of four normal brains were hybridized with biotinated repetitive DNA probes specific for the (peri)centromeric regions of chromosomes 1 and 7. Hybridization results were visualized with a peroxidase-DAB system after which the number of specific signals per nucleus was counted using bright field microscopy. Using the probe specific for chromosome 7 (p7t1), both the cerebral and the cerebellar samples showed 2 spots in 82% and 83%, respectively, of the nuclei. In situ hybridization with the chromosome 1 probe (pUC1.77) showed two spots in 69% of the cerebral nuclei. In cerebellar samples, hybridization with pUC1.77 resulted in only one large spot per nucleus in 82% of the cells. The average spot size in nuclei with one signal was about 1.6 times as large as that in nuclei with two signals. These observations suggest that the single large spot in the cerebellar cells is not the result of monosomy of chromosome 1 but that it reflects somatic pairing of the two chromosome 1 centromeres. Based on the size and the fraction of nuclei with one large spot, the small granular neuron is the most likely candidate. The difference between cerebral and cerebellar samples indicates that this somatic pairing of chromosome 1 is a cell-type-dependent phenomenon.

Cell Nucleus↗
PubMed1988

Beta-protein deposition: a pathogenetic link between Alzheimer's disease and cerebral amyloid angiopathies.

Cerebral amyloid angiopathy (CAA) refers to a group of hereditary (hereditary cerebral hemorrhage with amyloidosis, HCHWA and sporadic (SCAA) disorders characterized by amyloid fibril deposition restricted to the leptomeningeal and cortical vasculature leading to recurrent hemorrhagic and/or ischemic accidents. On clinical and biochemical grounds, two forms of HCHWA can be distinguished. The amyloid subunit of the HCHWA of Icelandic origin is related to Cystatin C, while amyloid from patients of Dutch origin (HCHWA-D) is related to the beta-protein (or A4), the main component of vascular and plaque core amyloid in Alzheimer's disease (AD) and Down's syndrome (DS) [corrected]. SCAA is an increasingly recognized cause of stroke in normotensive individual amounting to 5-10% of all cerebrovascular accidents. We now report the isolation and partial amino acid sequence of the amyloid subunit from a case of SCAA and a new case of HCHWA-D. The recognition that a heterogeneous group of diseases are linked by similar pathological and chemical features suggests that diversity of etiological factors may promote a common pathogenetic mechanism leading to amyloid-beta (A beta) deposition, and open new ways of research in AD and CAA as they are related to dementia and stroke.

Alzheimer Disease↗
PubMed1988

Different processing of Alzheimer's beta-protein precursor in the vessel wall of patients with hereditary cerebral hemorrhage with amyloidosis-Dutch type.

Hereditary cerebral hemorrhage with amyloidosis in patients of Dutch origin is an autosomal-dominant type of amyloidosis restricted to the small vasculature of the brain and clinically characterized by recurrent strokes. Amyloid fibrils from the leptomeninges of two patients were isolated and the primary structure determined. The complete sequence of the amyloid protein shows homology to the vascular (beta-protein) and plaque amyloid (A4-protein) obtained from Alzheimer's Disease. However, it is three residues shorter (39 instead of 42) than that reported for the plaque amyloid. The difference at the carboxy terminal may reflect specific degradation that occurs in the vessel wall and not in the brain parenchyma.

Alzheimer Disease↗
PubMed1988

Haemorrhagic necrosis of the grey matter of the spinal cord due to accidental injection of iopamidol in a patient with multiple neurofibromas; a clinico-pathological study.

Cervical laminectomy was performed in a 34-year-old man with multiple spinal neurofibromas because of a slowly progressive medullary compression. Four weeks later a rapid deterioration necessitated iopamidol myelography by left lateral cervical puncture at C2 level. Despite the establishment of adequate spinal fluid contact, resulting in imaging of the subarachnoid space, part of the contrast medium entered the spinal cord, thus delineating a syrinx from the upper cervical extending to the upper thoracic level. After the puncture the patient developed triplegia, involving the left arm and both legs and a paresis of the right arm. He died from aspiration pneumonia. Autopsy revealed haemorrhagic necrosis of the spinal grey matter. This adverse effect of myelography is argued to have been conditioned by the extreme immobility and displacement of the spinal cord due to the presence of multiple neurofibromas. The deterioration four weeks after the operation was probably caused by a further compression of the spinal cord.

Adult↗
PubMed1988

Hereditary cerebral haemorrhage caused by cortical amyloid angiopathy.

This article describes 136 patients with hereditary cerebral haemorrhages; all patients belonged to families (originally) resident in Katwijk (The Netherlands). Cases of hereditary cerebral haemorrhage have also been reported in NW-Iceland, and in the Dutch coastal village of Scheveningen. Katwijk is a Dutch fishing-village, located 20 miles north of Scheveningen. These 136 cases were encompassed in three large pedigrees, and the disorder followed an autosomal dominant mode of inheritance. No connection between the pedigrees from Iceland, Scheveningen and Katwijk has as yet been established. In our series, sclerosis with amyloid deposits could be observed in roughly a quarter of the small arteries and arterioles in the cerebral cortex and the covering arachnoid. The pathological vessels were irregularly distributed in areas and clusters, possibly leading to superficial cerebral infarcts and, secondarily, to haemorrhages. Our findings are identical with those described in patients from Scheveningen, but different from the Icelandic group. In addition to some differences in the age at onset and in the distribution of the angiopathy, it has recently been demonstrated that the amyloid in our patients is constituted by a microprotein which shows a homology to the beta-protein in Alzheimer's disease and Down's syndrome, while the amyloid in Icelandic cases is formed by an aggregation of cystatin C (gamma trace). An unexpected finding in most of our patients is the accumulation of senile plaque-like lesions in the cerebral cortex. We did not observe Alzheimer's fibrillary tangles in any of our cases.

Amyloidosis↗
PubMed1988

Microwave irradiation of human brain tissue: production of microscopic slides within one day.

A three step method using microwave irradiation enabled microscopic slides of human brain tissue to be obtained within one working day: steps 1 and 2 hardened and solidified brain tissue; step 3 completed formalin fixation. The efficacy and precision of the method was compared with slides of conventionally processed brain tissue that had been fixed in formalin for six weeks. The microscopic quality of the sections was excellent with good presentation of brain tissue and equalled that of conventionally processed slides.

Adult↗
PubMed1988

Dysphagia in inclusion body myositis.

Four elderly patients with inclusion body myositis and dysphagia are described. Dysphagia was the presenting symptom in three, preceding generalised weakness by 1.5 to 7 years. Myotomy of the cricopharyngeal muscle improved the symptoms and signs in 3 of the 4 patients. It is suggested that inclusion body myositis is not an infrequent cause of dysphagia in elderly people, and is amenable to treatment.

Aged↗
PubMed1987

Unclassified familial cardiomyopathy with ventricular dysrhythmia.

The case is described of a boy with some right ventricular dysplasia and episodes of ventricular tachycardia of left bundle branch block pattern who had symptoms from the age of 1 month. Angiography and cardiac biopsy demonstrated major involvement of the left ventricular myocardium. A sister of the patient presented at the age of 2 months with predominantly left ventricular cardiomyopathy; clinical signs and angiography suggested the presence of right ventricular dysplasia as well. She died suddenly at the age of 9 years. Her brother, now aged 14 years, is being treated with antiarrhythmic drugs. The hypothesis of this cardiomyopathy being a variant of "arrhythmogenic right ventricular dysplasia syndrome" is discussed.

Bundle-Branch Block↗
PubMed1987

Choroid plexus papilloma in the posterior fossa.

Choroid plexus papillomas in the posterior fossa can present with different clinical signs and symptoms. The tumors in the patients we discuss in this article originated from different sites of the choroid plexus. One patient, who had a fourth ventricle papilloma, experienced unsteady gait and episodes of dizziness over many years. The tumor was cystic an calcified, and adherent to the brain-stem. The second patient had only signs of increased intracranial pressure. A soft tumor was located in the cerebellomedullary cistern. The third patient, with a papilloma in the cerebellopontine angle, complained of hearing loss. This tumor was firmly adherent to the dura mater and looked exactly like a meningioma. The appearance on computed tomography scan, the macroscopic aspect, and the vascular supply of a papilloma in the posterior fossa can vary considerably.

Adult↗
PubMed1987

Hereditary cerebral hemorrhage with amyloidosis in patients of Dutch origin is related to Alzheimer disease.

Hereditary cerebral hemorrhage with amyloidosis in Dutch patients is an autosomal dominant form of vascular amyloidosis restricted to the leptomeninges and cerebral cortex. Clinically the disease is characterized by cerebral hemorrhages leading to an early death. Immunohistochemical studies of five patients revealed that the vascular amyloid deposits reacted intensely with an antiserum raised against a synthetic peptide homologous to the Alzheimer disease-related beta-protein. Silver stain-positive, "senile plaque-like" structures were also labeled by the antiserum, yet these lesions lacked the dense amyloid cores present in typical plaques of Alzheimer disease. No neurofibrillary tangles were present. Amyloid fibrils were purified from the leptomeningeal vessels of one patient who clinically had no signs of dementia. The protein had a molecular weight of approximately equal to 4000 and its partial amino acid sequence to position 21 showed homology to the beta-protein of Alzheimer disease and Down syndrome. These results suggest that hereditary cerebral hemorrhage with amyloidosis of Dutch origin is pathogenetically related to Alzheimer disease and support the concept that the initial amyloid deposition in this disorder occurs in the vessel walls before damaging the brain parenchyma. Thus, deposition of beta-protein in brain tissue seems to be related to a spectrum of diseases involving vascular syndromes, progressive dementia, or both.

Alzheimer Disease↗
PubMed1987

Hemostatic agents: brain tissue reaction and effectiveness. A comparative animal study using collagen fleece and oxidized cellulose.

In a series of 26 young rabbits, three cortical lesions were made in each hemisphere. Two of these holes were filled with collagen fleece (CF) and oxidized cellulose (OC), respectively, while the third was left empty as a control. The bleeding time was measured. Hemostasis with CF was statistically significantly faster than with OC, which in turn was statistically significantly faster than with no hemostatic agent. The animals were killed successively on Days 7, 14, 28, 42, and 241 after operation. Histopathological investigation showed that CF did not induce more tissue reaction that the control lesion and that CF was resorbed faster than OC. The removal of OC occurred from the borders of the material, moving gradually inward. With CF, there was an immediate ingrowth of reactive cells throughout the material. In contrast to OC, CF did not induce the formation of polynucleated giant cells. From these results, it can be concluded that CF is a fast, safe, and absorbable topical hemostatic agent suitable for use in neurosurgical procedures.

Animals↗