Tellurium and Thelaziasis

TELLURIUM, Tellurium, chemical symbol Te, occupies the 52nd place in the periodic system. A homolog of sulfur and selenium (VI group). Atomic weight 127.5. Tellurium is an amorphous black powder or brittle silver-white pieces with a metallic luster; specific gravity 6.24, melting point 453°. Tellurium directly combines with halogens, oxygen, hydrogen, and many metals. Tellurium compounds are used in biology when studying bacterial life for pigmenting the cells of microorganisms. When inoculating diphtheria bacilli onto a nutrient medium consisting of 50 cm³ of horse serum, 50 cm³ of a 0.8% sodium chloride solution, 2 cm³ of a 1% potassium tellurite solution (K₂Te), and one egg yolk, heated to coagulation at 85-90° for 12-14 hours, distinct colonies of diphtheria bacilli grow, colored in a dark color; all other microorganisms perish. To differentiate living tissue from tissue that has undergone coagulation under the influence of 96% alcohol, formalin, mercuric chloride, etc., the object is treated with a solution (1 : 10,000) of K₂Te and thoroughly washed with a physiological solution; in this case, living cells are stained. Tellurium compounds have a lethal effect on trypanosomes and typhoid bacilli; they produce a clearly expressed effect on the external manifestations of syphilis and on the seroreaction. As a therapeutic agent in humans and in experimental syphilis in animals, a 20% suspension of metallic tellurium in a 5% glucose solution or a 10% oily suspension of tellurium trioxide was used. Dose: 3 intramuscular injections of the tellurium-glucose suspension of 1-2 cm³ each, and then 0.5 cm³ of the 10% suspension, two to three injections per week. The use of tellurium is hindered by: frequent staining of the patient's skin to a blue color, changes in hair color, and a prolonged unpleasant garlic odor upon exhalation. In leprosy, a 10% suspension of metallic tellurium in a 5% glucose solution or a 10% suspension in oil of tellurium diiodide was used at 1-2 cm³ every 5-8 days, depending on the strength of the reaction. With a mild general reaction, improvement in leprosum nodes and tumors was noted; there were cases of regression and improvement in the presence of ulcers.

THELAZIASIS, a disease of the eyes of mammals and birds caused by nematodes of the genus Thelazia Railliet, 1819, family Thelaziidae, order Spirurata, localized in the conjunctival sac of the eye. In cattle, thelaziasis sometimes causes severe enzootics and is usually manifested by conjunctivitis, and in more severe cases by conjunctivo-keratitis. In humans, according to world literature, thelaziasis has been recorded 3 times (caused by the species Thelazia callipaeda Railliet et Henry, 1910). In the USSR, thelaziasis has not been established in humans, but one case of T. callipaeda infection was registered in a dog in the Far East (Dekhterev, 1929). The presence of the parasite in the conjunctival sac of the human eye causes severe irritation, pain, lacrimation, paralysis of the muscles of the lower eyelid, and ectropion. Therapy: the parasite can easily be extracted with eye forceps. Thelazia callipaeda is a thin, thread-like parasite (Fig. 1, 2). The head end is equipped with a buccal capsule and papillae (6 lateral and 8 submedian). The male is 10-14 mm in length, its tail end is narrowed and strongly curved. The spicules are unequal: the large one is 1.37-1.87 mm, the smaller one is 0.13-0.16 mm. There are 9 pairs of preanal papillae and 6 pairs of postanal papillae. The female is 12-18 mm in length, the vulva is at the level of the posterior third of the esophagus. The anus is 0.077-0.115 mm from the tail end. Viviparous. They require an intermediate host, which is apparently an insect. The obligate host is the dog.