Nerve function

Ruijten MW, Verberk MM, Salle HJ. 1991. Nerve function in workers with long term exposure to trichloroethene. Br J Ind Med 48 87-92. 

NS (occup) Neurological No effect on peripheral nerve function 60-80 (levels measured) Ishida et al. 1996 Spivey et al. 1980... 

NS (occup) Neurological Peripheral nerve function in adults decreased nerve conduction velocity 30- 70 Araki et al. 1980 Chia et al. 1996 Muijser et al. 1987 Rosen et al. 1983 Seppalainen et al. 1983 Triebig et al. 1984... 

Although histamine is not stored in neurons outside of the central nervous system, mast-cell-derived histamine can modify peripheral sensory nerve function. Both acute and chronic pain states can result from inflammation or peripheral nerve cell injury, and there is substantial evidence that mast cell histamine participates in these disorders. 

Impairment of eighth cranial nerve function is the most important adverse effect of streptomycin. Vestibular function is most frequently affected, but hearing may also be impaired. Audiometric testing should be performed in patients who must receive streptomycin for more than 2 months. Streptomycin occasionally causes nephrotoxicity. 

Nervous system disorders are diagnosed by examining the patient s mental status, cranial nerve function, motor system reflexes, and sensory systems. An electroencephalogram (EEG) tests higher brain and nervous system functions. 

Based on the available data, the concentrations of hexachloroethane at hazardous waste sites are unlikely to reach levels that would elicit a neurological response in humans. However, there have not been any comprehensive studies of brain or nerve function after exposure to hexachloroethane. 

By using tiny probes as neural prostheses, scientists may be able to restore nerve function in quadriplegics and make the blind see or the deaf hear. Thanks to advanced techniques, a single, small, implanted probe can stimulate individual neurons electrically or chemically and then record responses. Preliminary results suggest that the microprobe telemetry systems can be permanently implanted and replace damaged or missing nerves. 

No population has been identified which is unusually susceptible to toxic effects resulting from -hexane exposure. It is possible that individuals with diminished peripheral nerve function may be more susceptible to w-hcxanc neurotoxicity than the general population. This group would include diabetics, alcoholics and the aged. 

Saxitoxins Water-soluble toxins that prevent proper nerve functioning. 

Saxitoxins are water-soluble compounds that prevent proper nerve functioning. They are produced in nature by plant-like marine protozoa called dinoflagellates. Humans typically acquire such toxins by eating bivalve mollusks fed on dinoflagellates. A terrorist would likely deliver a saxitoxin as an aerosol or use it as a poison to contaminate food or water. 

Assuming that this explanation of Parkinson s disease is correct, a possible treatment for the condition is apparent Provide patients with an increased supply of dopamine. With additional levels of dopamine in the body, normal nerve function might be expected to be restored, and the symptoms of Parkinson s might be reduced. This form of therapy appears to make theoretical sense, and it has formed... 

Drugs used in the treatment of hypertension vary greatly in their mode of interference with sympathetic nerve function. In the case of methyldopa the mechanism is complex and still largely unknown. Others, such as guanoxan, guanochlororbethanidine, involve varying degrees of, for example catecholamine depletion, blockade of subsequent release of noradrenaline and, occasionally, a weak receptor-blockade. Bethanidine is perhaps the best-known of this series and... 

Following the discovery that xylocholine blocked transmission at sympathetic nerve terminals, intensive chemical and biological investigations of related compounds revealed that various benzyl quaternary ammonium salts were potent and selective inhibitors of adrenergic nerve function. A review of compounds of this type has been published by Copp [239]. A -2-Bromobenzyl-A(-ethyl-A. A-dimethylammonium tosylate (LIII) (bretylium) has been studied extensively [237, 258], and suppression of adrenergic nerve function has been demonstrated in numerous test situations in various animal species. 

The Peripheral Nerve Function test guideline (OPPTS 870.6850) defines procedures for evaluating certain aspects of the neurophysiological functioning of peripheral nerves. The purpose of the guideline is to evaluate the effects of exposures on the velocity and amplitude of conduction of peripheral nerves. Additional tests may be necessary to completely assess the neurophysiological effects of any substance. 

Monitoring renal and eighth cranial nerve function at onset of therapy is essential for patients with known or suspected renal impairment and also in those whose renal function is initially normal but who develop signs of renal dysfunction. 

Peripheral nerve functions are not affected equally by local anesthetics. Loss of sympathetic function usually is followed by loss of temperature sensation sensation to pinprick, touch, and deep pressure and last, motor function. This phenomenon is called differential blockade. Differential blockade is the result of a number of factors, including the size of the nerve, the presence and amount of myelin, and the location of particular fibers within a nerve bundle. For conduction to be effectively blocked, the local anesthetic must exert its effects over the distance between several nodes of Ranvier. Since the smallest nerves (C fibers) have no myelin, they can be most easily blocked thus, sympathetic functions often are blocked soon after a local anesthetic is applied to a particular nerve bundle. Small myelinated nerves have correspondingly short distances between nodes of Ranvier and therefore are often blocked next. These nerves subserve temperature and sharp pain sensation. Larger nerves then become blocked, accounting for the loss of function up to and including motor innervation. 

Repeat-dose neurotoxicity studies may identify behavioral effects or impaired nerve functions that can interfere with mating or maternal care. Developmental neurotoxicity studies have been conducted for specific pesticide classes, following requirements of US-EPA. If such a study is available it can be examined not only for the study-specific endpoints on the developing brain but also compared to the prenatal toxicity study and the two-generation smdy with respect to general endpoints of pre- and postnatal development, respectively. 

Mechanism of Action An antihypertensive that depletes stores of catecholamines and 5-hydroxytryptamine in many organs, including the brain and adrenal medulla. Depression of sympathetic nerve function results in a decreased heart rate and a lowering of arterial blood pressure. Depletion of catecholamines and 5-hydrox-ytryptamine from the brain is thought to be the mechanism of the sedative and tran-quilizing properties. Therapeutic Effects Decreases blood pressure and heart rate sedation. 

---