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Biomedical subjects

N K Blank

Publications and source records attributed to N K Blank.

At least 37 records · Page 2Linked to original sources
PubMed1981

Myelination of central nervous system axons in tissue culture by transplanted oligodendrocytes.

Unmyelinated mouse cerebellar cerebellar cultures in which oligodendrocyte differentiation had been suppressed by exposure to cytosine arabinoside developed axonal myelin after superimposition of kainic acid-treated cerebellar explants devoid of myelin-receptive axons. The latter explants contained differentiated oligodendrocytes. The operation of a diffusible myelin-stimulating factor was ruled out by the failure of myelination in cytosine arabinoside-exposed explants not in direct contact with oligodendrocyte-containing transplants.

Animals↗
PubMed1980

Apneic spells in progressive dialysis encephalopathy.

A 53-year-old patient with progressive dialysis encephalopathy is discussed. In addition to the clinical features previously described in this syndrome, the patient had spells of sudden respiratory arrest in close association with the episodic EEG abnormalities characteristic of the syndrome.

Apnea↗
PubMed1979

Toxic effects of kainic acid on mouse cerebellum in tissue culture.

Cultures of mouse cerebellum were exposed for various intervals after explantation to kainic acid, a glutamic acid analog. Purkinje cells and intracerebellar nucleus neurons were destroyed and cortical laminar formation was inhibited by exposure to kainic acid, while granule cells were relatively spared. Prolonged kainate treatment also reduced the granule cell population. The destructive effects of kainic acid were evident upon exposure of Purkinje cells prior to the development of parallel fiber-Purkinje cell synapses, the neurotransmitter for which is believed to be glutamic acid. Glutamate application to intracerebellar nucleus neurons in vitro did not evoke extracellularly recorded excitatory effects, suggesting that these kainate-sensitive neurons do not have significant numbers of glutamate receptors. The combination of these observations suggests that neuronal toxic effects of kainic acid are not exclusively mediated by action on glutamate receptors, but involve other, less specific mechanisms as well.

Animals↗
PubMed1979

Sporadic distal myopathy with early adult onset.

With the exception of the large series of adult-onset hereditary distal myopathy from Sweden, few cases of primary muscle disease with a definite distal predilection have been published. We report 3 sporadic cases of distal myopathy with the following features: (1) early adult onset (26 to 33 years); (2) slowly progressive weakness affecting first the distal leg muscles and later the arms; (3) marked elevation of creatine phosphokinase (more than 10 times the normal value); and (4) electromyographic and histological evidence of myopathy in distal muscles. The differential diagnosis is discussed and other reported cases are reviewed. The differences between hereditary cases reported by others and the sporadic cases reported here form the basis for a tentative subclassification of this syndrome.

Adult↗
PubMed1978

Posterior fossa subdural hematomas in neonates.

Posterior fossa subdural hematomas in the newborn infant are rare but potentially treatable. The infants are normal after birth, but within days, hydrocephalus hypotonia, and irregular respirations develop. Seizures and third nerve pareses are unusual. We report a neonate in whom this process was identified by computerized tomographic brain scan. We also discuss potential misinterpretations of the computerized tomographic brain scan in neonates.

Cranial Fossa, Posterior↗
PubMed1978

Multifocal pontine lesions in cancer patients treated with chemotherapy and CNS radiotherapy.

Multifocal pontine lesions were found at postmortem examination in four patients with various types of malignancy. The patients had undergone extensive evaluation and treatment with multiple chemotherapy regimens as well as radiotherapy to the central nervous system. The histologic character and striking anatomic distribution of the pontine lesions are described and their possible pathogenesis discussed.

Adolescent↗
PubMed1976

'Glioblastoma'. Induction of a reproducible autochonous tumor in rats with murine sarcoma virus.

Inoculation of 0.02 ml of high-titer Kirsten strain Murine Sarcoma Virus into the brains of 10-day-old Wistar/Furth rats yields, with 100 percent incidence, a uniform glioblastoma-like tumor within 16 days. Light and electronmicroscopy confirmed the neuroectodermal origin of the parenchymal cells. The remarkable vascular component was studied with extracellular tracers. The permeability of the abnormal endothelium to constituents of the blood vascular compartment was confirmed. Accessory vascular channels, and blood channels devoid of endothelium entirely, were observed. This reporducible system should provide a useful model for further studies of the biology of brain tumors.

Animals↗
PubMed1975

Wernicke's encephalopathy: an experimental study in the rhesus monkey.

Experimental Wernicke's encephalopathy, induced in rhesus monkeys with a diet lacking thiamine (vitamin B1), is characterized by cavitary necrosis of the striatum as well as a microvacuolar periventricular lesion of the brain stem such as occurs in man. With high resolution light microscopy and electron microscopy, the primary structural alteration in the brain stem lesion, and probably also in the striatum, appears to be that of widespread "blister" formation due to splitting of myelin at the intraperiod line. Microvascular alterations were minimal, even in the most severely affected regions. It is the myelin blisters which give rise to the spongy texture of the neuropil. A similar splitting of myelin has been described in several other experimental encephalopathies, and it is probable that it also occurs in Wernicke's encephalopathy in man.

Animals↗