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S C Apfel

Publications and source records attributed to S C Apfel.

24 records · Page 2Linked to original sources

Effects of administration of ciliary neurotrophic factor on normal motor and sensory peripheral nerves in vivo.

Ciliary neurotrophic factor (CNTF) has a variety of effects on different neuronal populations in vitro, but little has been reported concerning its effects in vivo. This study examined the effects of CNTF administration on peripheral nerves both in young growing rats and in more mature animals. In both young and fully grown rats, CNTF stimulated levels of substance P and calcitonin gene related peptide in sensory spinal ganglia. In immature rats, CNTF increased compound nerve conduction velocity and motor nerve conduction velocity. By contrast, electrophysiological measurements were not affected in fully grown animals. There was a biphasic dose response to CNTF for the electrophysiologic changes with larger changes noted at a dose of 0.1 micrograms/g body weight than at a dose of 0.25 micrograms/g. There were no behavioral changes noted at either dose of the factor. These observations indicate that CNTF administration in vivo can influence neural physiology, and suggest that the factor may be useful for the treatment of disorders involving either sensory or motor peripheral nerves.

Aging↗

Nerve growth factor prevents experimental cisplatin neuropathy.

Cisplatin is a widely used antitumor agent, the dose-limiting toxicity of which is predominantly large-fiber sensory neuropathy. Prevention of such a neuropathy would extend the usefulness of this agent, allowing higher doses and longer periods of treatment. We report here that we have successfully established cisplatin neuropathy in mice measured by using behavioral, biochemical, and electrophysiological techniques, and that subcutaneous administration of human recombinant nerve growth factor (NGF) prevents or delays the neuropathy. Cisplatin administration reduced sensory ganglion levels of the peptide transmitter, calcitonin gene-related peptide, slowed nerve conduction in the tail and impaired proprioception as measured by the ability to balance on a rotating dowel. NGF coadministration appeared to prevent all these abnormalities. Treatment of the human toxic neuropathy with its well-established time of onset, simple clinical course, and the accessibility of nerve to NGF administered systemically may provide the best clinical setting for the first human trials of NGF.

Animals↗

Nerve growth factor prevents toxic neuropathy in mice.

Taxol is a promising new antitumor drug with therapeutic use that is limited by a toxic sensory neuropathy. Taxol is also cytotoxic to dorsal root ganglion neurons in vitro, but this effect is prevented by cotreatment with the trophic protein, nerve growth factor. We sought to develop an animal model and then to determine whether nerve growth factor can prevent taxol neuropathy in vivo. Administration of taxol to mice resulted in a profound sensory neuropathy characterized by decreases in dorsal root ganglion content of the peptide neurotransmitter, substance P, elevated threshold to thermally induced pain, and diminished amplitude of the compound action potential in the caudal nerve. Coadministration of nerve growth factor prevented all of these signs of neurotoxicity. These findings suggest that administration of nerve growth factor may prevent certain toxic sensory neuropathies.

Alkaloids↗

Taxol produces a predominantly sensory neuropathy.

Taxol, a plant alkaloid with promise as an antineoplastic agent, produced a predominantly sensory neuropathy in 16 of 60 patients treated in two phase I trials. This neuropathy occurred only at taxol doses greater than 200 mg/m2. Symptoms typically started 1 to 3 days following treatment, beginning in the hands and feet simultaneously in most patients. Electrophysiologic data suggests both axonal degeneration and demyelination. This previously undefined neurotoxic neuropathy most likely results from taxol's unique ability to produce microtubule aggregation in dorsal root ganglion cells, axons, and Schwann cells.

Adult↗

Neurotrophic factors in the treatment of neurotoxicity: an overview.

In recent years, major advances have been made in our understanding of neurotrophic factors and the role they play in the development and maintenance of the nervous system. This knowledge, combined with major advances in molecular biology, have enabled investigators to begin considering their applications to clinical problems. The toxic neuropathies may prove to be one of the simplest and most practical clinical settings for the early use of neurotrophic factors. In this brief review, we provide an overview of some of the most important neurotrophic factors, and summarize the major preclinical studies which suggest that they may be useful in the treatment of toxic neuropathy.

Animals↗