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W Straks

Publications and source records attributed to W Straks.

14 recordsLinked to original sources
PubMed1991

Ventricular tachycardia after in vivo DC shock ablation in dogs. Electrophysiologic and histologic correlation.

BACKGROUND: DC shock catheter ablation for the treatment of ventricular tachycardia (VT) may induce VT episodes that disappear within days. METHODS AND RESULTS: A 30-J cathodal shock was delivered to the endocardial left ventricular wall in 15 closed-chest dogs. All dogs had VT during the first day after ablation. Eleven of these dogs were studied on the first day. Extensive epicardial and endocardial activation mapping in vivo, in Langendorff-perfused hearts, and in tissue blocks in a tissue bath localized the site of origin of VT to subendocardial Purkinje fibers in a border zone surrounding the central necrotic ablation lesion. Intracellular recording showed that this zone consisted of a subendocardial superficial layer (SSL) of cells with abnormal characteristics, a resting membrane potential (RMP) of -58 +/- 11 mV (mean +/- SD), and an action potential amplitude (APA) of 61 +/- 20 mV. In addition, the steepness of phase 0 of the action potential was markedly reduced. In three dogs abnormal automaticity was found in a very small area. Immediately below the SSL, cells were normal with an RMP of -78 +/- 5 mV and an APA of 107 +/- 8 mV. Histology confirmed a thin SSL with edematous and necrotic cells, hemorrhage, and infiltration. The other four dogs were studied at 1 week after ablation when VT was absent. Microelectrode impalement in the SSL was either impossible or showed nearly normal action potential characteristics. Histological examination showed a markedly thickened fibrotic subendocardial layer at places where impalement was impossible. Normal subendocardium was found in other areas of the border zone. CONCLUSIONS: Our results indicate that VT after DC shock ablation originates from cells with abnormal automaticity in the superficial subendocardial border zone around the central ablation lesion. Within 1 week edematous and necrotic cells in this border zone are replaced by a fibrotic layer, and this transition is associated with the disappearance of VT.

Animals↗
PubMed1988

Pulmonary hyalinizing granuloma.

A patient with pulmonary hyalinizing granuloma (PHG) is presented. PHG is a rare disease with very specific histological characteristics. Roentgenograms display multiple bilateral pulmonary nodules which may be cavitated. Evidence exists that the nodules are the result of an exaggerated chronic immune response. The course of the disease is generally favourable. PHG should be considered in patients showing multiple bilateral pulmonary nodules.

Female↗
PubMed1986

Electrical catheter ablation in the left and right ventricular wall in dogs: relation between delivered energy and histopathologic changes.

Electrical catheter ablation of arrhythmogenic sites is now being used for the treatment of ventricular tachycardias. However, the extent and type of the ablation lesion in relation to energy level are controversial and not well known. In 10 beagles, single cathodal shocks of 30 (4 dogs), 80 (2 dogs) or 250 J (4 dogs) were delivered to the endocardial ventricular wall (5 dogs left ventricular, 5 dogs right ventricular). One week after ablation the dogs were killed for histopathologic examination. In the left ventricular wall, ablation lesion volumes calculated from measured extensions in three perpendicular directions were 0.4 and 0.9 cc at 30 J, 1.9 cc at 80 J and 2.8 and 3.4 cc at 250 J; in the right ventricular wall they were 0.4 and 0.5 cc at 30 J, 1.3 cc at 80 J and 2.5 and 4.2 cc at 250 J. In the right ventricular wall all 30 to 250 J lesions were transmural, whereas in the left ventricular wall only 250 J lesions were transmural. All lesions showed a necrotic area surrounded by granulation tissue with degenerated myofibrils. Thus, the size of the ablation lesion depends on delivered energy, whereas the pattern of histopathologic change is identical in the 30 to 250 J energy range. These results suggest that with accurate localization of the arrhythmogenic site one low energy shock may be successful with less myocardial damage.

Animals↗
PubMed1985

Glycosaminoglycans in myxoma of the jaw: a biochemical study.

Myxoma of the jaw is classified as an odontogenic tumor although final proof for an odontogenic origin is lacking. In the present study glycosaminoglycans (GAG's) in the extracellular matrix of a jaw myxoma were analyzed and compared with known data on GAG's in dental tissues. It was noted that the GAG's formed approximately 1% of the total tumor weight and 17% of the dry weight. Hyaluronic acid formed 72.4% of the GAG-fraction. Neither this high GAG-content nor the high fraction of hyaluronic acid are found in dental tissues and it is concluded that the myxoma matrix differs from the matrix in dental pulp and periodontal ligament.

Adult↗
PubMed1983

Primitive neuroectodermal tumour of the maxilla. Light microscopy and ultrastructural observations.

Primitive neuroectodermal tumour is a rarely encountered lesion, mainly occurring within the central nervous system. A case is reported in which the tumour was situated in the anterior maxilla. Light microscopy and ultrastructural features that made it possible to differentiate the lesion from other small round-cell tumours are discussed. Combined surgical and radiotherapeutic intervention proved to be successful in eradicating the neoplasm.

Child↗
PubMed1982

Sertoli cell and sertoli-Leydig cell tumors of the ovary. A report of three cases with ultrastructural findings.

Three tumors of the ovary containing Sertoli cells were studied by light and electron microscopy. Two of these tumors were well-differentiated neoplasms with epithelial cells often forming tubules. These cells were cylindrically shaped, contained round to oval nuclei and stood on a thin basement membrane. The cytoplasm was fibrillary and showed rough and smooth endoplasmic reticulum, lipid droplets and secretory granules. At the luminal borders the cells were often irregular and displayed apocrine-like activity. Having compared our data with results of studies from the literature of normal Sertoli cells, Sertoli cell adenomas of the testis and cells from other parts of the male reproductive system and those of normal ovarian stroma, we conclude that the Sertoli cell is most probably the cell of origin of these tumors. The third tumor was undifferentiated with a sarcomatoid appearance and contained islands of cartilage, which we consider to be metaplastic.

Adult↗
PubMed1982

Menkes' kinky hair disease. II. A clinicopathological report of three cases.

The neuropathologic abnormalities in three new cases of Menkes' kinky hair disease are described. Principally the three cases were the same. Hypoplasia of the cerebellum, with a basal arachnoïdal cyst, was present in all three cases. The cysts were not described before in Menkes' disease. There was nerve cell loss and gliosis in the cerebral cortex, cerebellum and thalamus. The reduction of myelinated axons was widespread and the disease does not belong to the leukodystrophies. Cortical lamination disturbances were present indicating that the disease develops as early as the sixth fetal month. Abnormal arborization of Purkinje cells with swelling of dendrites was present and thought not to be identical with the Purkinje cell abnormalities seen in amaurotic idiocy. The difference in severity of the copper deficiency in 2 patients is compared with the situation in "brindled" and "blotchy" mutant mice.

Brain↗
PubMed1978

Computerized axial tomography and cerebral scintigraphy in leukodystrophy. A study of two boys presumably suffering from lysosomal disease.

Two unrelated boys, 12 and 9 years old, suffered from a diffuse cerebral disease that followed a parallel, subacute course. Mental regression, loss of hearing and vision, spastic-ataxic and pseudobulbar disturbances, and atrophy of the optic nerves occurred in both. Enzyme studies and the liver biopsy of one of the patients suggest a "lysosomal disease." The hallmark of both patients is the striking similarity of the cerebral scintigraphy and the computerized axial tomography (CT). Cerebral scintigraphy showed annular and crescent-shaped areas of increased radioactivity in the parietoccipital region. The CT indicated bilateral, symmetric bands of elevated density after contrast enhancement in the paraventricular white matter in the same region. These findings and the neurologic symptoms are compatible with leukodystrophy. Thus cerebral scintigraphy and CT appear to be useful aids in the diagnosis of metabolic brain disease. Computerized axial tomography is preferred for distinguishing whether lesions are in white or gray matter.

Brain↗
PubMed1978

Metachromatic leukodystrophy: a comparative study of the ultrastructural findings in the peripheral nervous system of three cases, one of the late infantile, one of the juvenile and one of the adult form of the disease.

The ultrastructural findings in the peripheral nerve of three cases of M. L. D., namely of the late infantile, the juvenile and the adult form are described. The pathological changes consist of two phenomena: segmental demyelination and lysosomal storage of sulfatides, both probably separate results of a deficiency of the enzyme Arylsulfatase A. Some differences are found in the degree of segmental demyelination and the type of lysosomal storage products. A possible relation between these differences and the supposed difference in the defect of the enzyme Arylsulfatase A, responsible for the different subtypes of the disease, is postulated.

Adolescent↗
PubMed1977

[Fucosidosis].

Explore the source record for details and available documents.

Fabry Disease↗
PubMed1977

Fucosidosis. II. Ultrastructure.

The ultrastructural changes of a sural nerve biopsy, liver biopsy and the autopsy of a case (I) of fucosidosis are described. Light microscopy revealed the presence of foam cells in various organs. The contents of the vacuoles stained positive with P.A.S. and Sudan. Electron microscopical examination showed inclusions in hepatocytes, Schwann cells and neurons. These inclusions had a single limiting membrane and contained heterogeneous structures, vesicular, multivesicular and membrane like structures, forming concentric lamellae. In another patient (case III) with a different clinical presentation and a different enzyme pattern (a reduced alpha-L-fucosidase activity, in combination with a reduced arylsulfatase A activity) similar abnormalities as in case I were found in a sural nerve and liver biopsy. It is suggested that the combined reduction of enzyme activity is responsible for the disease.

Autopsy↗
PubMedDate not supplied

A congenital variant of glycogenosis type IV.

Three related patients are described with glycogenosis type IV with an unusual clinical presentation resulting in perinatal death. Stored material showed birefringent Maltese crosses and was present in skeletal muscles, heart, central nervous system, and liver. Muscular dysfunction resulted in a fetal hypokinesia sequence with arthrogryposis and lung hypoplasia. A subdivision of glycogenosis type IV in four subtypes is proposed, based on age of onset. Measurement of the enzyme activities in different tissues does not permit, at the moment, a distinction between the subtypes.

1,4-alpha-Glucan Branching Enzyme↗