Ocular problems are common in children with other disabilities. Delay in the detection and treatment of these disorders compounds the already existing disability in these children. Lack of awareness and sensitization among the parents and teachers is a matter of great concern. Therefore, strategies regarding increasing awareness, mandatory ocular examination in these children and early detection and treatment of the ocular disorders is the need of the hour.

Both streptomycin and dihydrostreptomycin in large doses produced neuromuscular blockade in different types of skeletal nerve-muscle preparations. Streptomycin had a quicker, more marked and a longer-lasting action than dihydrostreptomycin. Neostigmine reversed a partial block of streptomycin, but a complete neuromuscular block remained unaffected. Calcium ions antagonized the neuromuscular block of streptomycin rapidly but incompletely.Both streptomycin and dihydrostreptomycin may cause a number of untoward phenomena, particularly injury to the nervous system and hypersensitivity reactions. The main toxic sideeffect in the chronic use of streptomycin is damage to the vestibular mechanisms and the eighth cranial nerve, which was first described in man by Hinshaw and Feldman (1945) and in experimental animals by Molitor and his collaborators (1946, 1950). The latter authors also showed that streptomycin in high dosage caused death in experimental animals as a result of respiratory failure. Brazil and Corrado (1957) studied the motor effects of streptomycin in dogs and in pigeons, and they found that streptomycin possesses neuromuscular blocking properties which are similar to those produced by magnesium. Calcium and neostigmine suppressed the motor effects of acute streptomycin intoxication. Brazil and Corrado (1957) Rat Phrenic Nerve-Diaphragm Preparation.-This was prepared as described by BUlbring (1946). Ten adult rats were used. The isolated tissues were suspended in a 60 ml. bath, containing Tyrode solution with double the amount of dextrose. Single shocks at rates not exceeding 8/min. were applied to the nerve from a square wave stimulator, at 10 to 12 volts and 0.5 to 1.0 msec. duration. Drugs were added directly to the bath through a very fine polythene tube attached to a hypodermic needle. Dog Sciatic-Gastrocnemius Preparation.-Experiments were performed in 10 dogs anaesthetized with sodium pentobarbitone (35 mg./kg.) injected intraperitoneally. One leg was immobilized and the sciatic nerve was exposed between the hamstring muscles and sectioned. The peripheral stump of this nerve was placed on a non-polarizing bipolar electrode. The contractions of the gastrocnemius muscle were recorded with an isometric lever. The muscle was stimulated through the sciatic nerve by a square wave stimulator at a rate of 8/min. at 10 to 12 volts and 0.5 to 1.0 msec. duration. Retrograde injections of drugs were made through the cannulated common iliac artery.Frog Rectus A bdominis Muscle Preparation.-Frogs were pithed and the rectus abdominis muscle was dissected and suspended in a 10 ml. bath containing oxygenated frog-Ringer solution at room temperature. The contractions produced by acetylcholine chloride (0.10 to 1.0 pxg./ml.), when added to the bath and left in contact with the tissue for 90 sec., were recorded. Streptomycin and dihydrostreptomycin were added to the bath 30 sec. before a subsequent addition of acetylcholine and the contractions again recorded for 90 sec. The bath was then washed out. Between success...

I Isolated duodenum of the rat, exposed to ultraviolet (u.v.) light in the presence of NO2 ions, responded with reversible relaxation. 2 The photorelaxation response did not seem to involve any known receptor mechanisms and was independent of any ganglionic or neuronal influences. 3 Changes in the ionic environment of the tissue showed that Na+ and Ca2 + were essential for the photorelaxation. K+depolarized-tissue did not show the photoresponse. 4 The presence of the metabolic inhibitors, iodoacetic acid, 2,4-dinitrophenol, sodium fluoride, sodium azide or potassium cyanide, abolished the photorelaxation response. 5 It is proposed that the photorelaxation of the tissue resulted from the liberation of metabolic energy following NO2 ion-dependent absorption of u.v. light energy, which in turn, interfered with the Na+ ion movement across the cell membrane.

Sumary1. The effects of some drugs known to inhibit transmission in the superior cervical ganglion and at the neuromuscular junction were investigated on the cholinergic nerve-smooth muscle junction, using the rat isolated innervated urinary bladder preparation.