ABSTRACT
In a study of chronic lead intoxication in mature chickens, blood lead levels were significantly lower in hens than in roosters receiving the same oral dose of lead. It was then shown that eggshells from lead-treated hens contained 6-12 times the lead concentration of eggshells from control hens. Similarly, the lead content of egg yolks from treated hens was significantly higher than yolks from controls. Lead-treated hens laid significantly more eggs during the period of observation of nearly 3 years because of the increased frequency of laying cycles, which was almost three times that of control hens. A further observation was histologic damage to the mature testes of the rooster.
Subject(s)
Chickens/physiology , Lead Poisoning/veterinary , Ovum/analysis , Age Factors , Animals , Body Weight , Chronic Disease , Egg Shell/analysis , Egg Yolk/analysis , Female , Lead Poisoning/pathology , Lead Poisoning/physiopathology , Male , Oviposition , Poultry Diseases/pathology , Poultry Diseases/physiopathology , Testis/pathologyABSTRACT
In order to study the possible etiologic role of lead in human motor neuron disease we produced chronic lead intoxication in the chicken by daily administration of lead acetate. Control animals received sodium acetate. During life, periodic measurements were made of motor function, motor nerve conduction velocity and response amplitude. After sacrifice, histologic analysis was performed on spinal cord, peripheral nerve and muscle. A syndrome was produced characterized by a fall in motor response amplitude, spinal motor neuron degeneration, motor axonal loss and atrophy of muscle, similar to that seen in human motor neuron diseases.
Subject(s)
Lead Poisoning/physiopathology , Motor Neurons/pathology , Neuromuscular Diseases/chemically induced , Neurotoxins/pharmacology , Animals , Chickens , Female , Lead Poisoning/pathology , Male , Neural Conduction , Neuromuscular Diseases/pathology , Neuromuscular Diseases/physiopathology , Neurotoxins/pharmacokinetics , Peripheral Nerves/drug effects , Peripheral Nerves/pathology , Peripheral Nerves/physiopathology , Spinal Cord/drug effects , Spinal Cord/pathology , Spinal Cord/physiopathologyABSTRACT
Mycoplasma pneumoniae infection has been associated with a variety of neurologic complications involving the central nervous system, the peripheral nervous system and muscle. We present a patient who developed a previously unreported complication: mononeuritis multiplex. This consisted of a severe brachial plexus neuropathy with contralateral cervical monoradiculopathy.
Subject(s)
Brachial Plexus , Neuritis/complications , Pneumonia, Mycoplasma/complications , Adult , Humans , Male , Peripheral Nervous System Diseases/complicationsABSTRACT
The results of evaluation of the autonomic nervous system of a patient with amyotrophic lateral sclerosis are presented. As previously reported, parasympathetic function and sympathetic adrenergic function were normal as assessed by cardiovascular reflexes. However, a disturbance in sympathetic cholinergic function as measured by the sympathetic skin response was demonstrated. We suggest that the latter test be included in all electrophysiological evaluations of autonomic function in amyotrophic lateral sclerosis.
Subject(s)
Amyotrophic Lateral Sclerosis/physiopathology , Sympathetic Nervous System/physiopathology , Cardiovascular System/physiopathology , Cholinergic Fibers/physiology , Galvanic Skin Response/physiology , Humans , Male , Middle Aged , Muscles/physiopathology , Parasympathetic Nervous System/physiopathology , Reflex/physiologyABSTRACT
A prospective study of 20 normal subjects was undertaken to determine the effect of three ankle positions (active dorsiflexion, active plantar flexion, natural or rest position) on comfort and facilitation of quadriceps contraction in isometric strengthening in a supine position with the hip and knee fully extended. Surface EMG activity was found to be greatest for the vastus lateralis followed by the vastus medialis and least for the rectus femoris. Equal facilitation was apparent with either active ankle dorsiflexion or plantar flexion. Both were superior to the natural (rest) position. In situations where isometric quadriceps exercises are required, the authors recommend either active ankle dorsiflexion or plantar flexion to facilitate quadriceps strengthening. The choice between the two positions should be based on patient comfort.
